Sample records for copper chromate acc

  1. Chromate Reduction by a Pseudomonad Isolated from a Site Contaminated with Chromated Copper Arsenate

    PubMed Central

    McLean, Jeff; Beveridge, Terry J.

    2001-01-01

    A pseudomonad (CRB5) isolated from a decommissioned wood preservation site reduced toxic chromate [Cr(VI)] to an insoluble Cr(III) precipitate under aerobic and anaerobic conditions. CRB5 tolerated up to 520 mg of Cr(VI) liter−1 and reduced chromate in the presence of copper and arsenate. Under anaerobic conditions it also reduced Co(III) and U(VI), partially internalizing each metal. Metal precipitates were also found on the surface of the outer membrane and (sometimes) on a capsule. The results showed that chromate reduction by CRB5 was mediated by a soluble enzyme that was largely contained in the cytoplasm but also found outside of the cells. The crude reductase activity in the soluble fraction showed a Km of 23 mg liter−1 (437 μM) and a Vmax of 0.98 mg of Cr h−1 mg of protein−1 (317 nmol min−1 mg of protein−1). Minor membrane-associated Cr(VI) reduction under anaerobiosis may account for anaerobic reduction of chromate under nongrowth conditions with an organic electron donor present. Chromate reduction under both aerobic and anaerobic conditions may be a detoxification strategy for the bacterium which could be exploited to bioremediate chromate-contaminated or other toxic heavy metal-contaminated environments. PMID:11229894

  2. Alternatives to chromated copper arsenate for residential construction

    Treesearch

    Stan T. Lebow

    2004-01-01

    For decades chromated copper arsenate (CCA) was the primary preservative for treated wood used in residential construction. However, recent label changes submitted by CCA registrants will withdraw CCA from most residential applications. This action has increased interest in arsenic free preservative systems that have been standardized by the American Wood Preservers...

  3. New Approach to Remove Metals from Chromated Copper Arsenate (CCA)-Treated Wood

    Treesearch

    Todd F. Shupe; Chung Y. Hse; Hui Pan

    2012-01-01

    Recovery of metals from chromated copper arsenate (CCA)-treated southern pine wood particles was investigated using binary acid solutions consisting of acetic, oxalic, and phosphoric acids in a microwave reactor. Formation of an insoluble copper oxalate complex in the binary solution containing oxalic acid was the major factor for low copper removal. Furthermore, the...

  4. Alternatives to chromated copper arsenate (CCA) for residential construction.

    Treesearch

    Stan Lebow

    2004-01-01

    For decades chromated copper arsenate (CCA) was the primary preservative for treated wood used in residential construction. However, recent label changes submitted by CCA registrants will withdraw CCA from most residential applications. This action has increased interest in arsenic-free preservative systems that have been standardized by the American Wood Preservers’...

  5. Identification of a copper(I) intermediate in the conversion of 1-aminocyclopropane carboxylic acid (ACC) into ethylene by Cu(II)-ACC complexes and hydrogen peroxide.

    PubMed

    Ghattas, Wadih; Giorgi, Michel; Mekmouche, Yasmina; Tanaka, Tsunehiro; Rockenbauer, Antal; Réglier, Marius; Hitomi, Yutaka; Simaan, A Jalila

    2008-06-02

    Several Cu(II) complexes with ACC (=1-aminocyclopropane carboxylic acid) or AIB (=aminoisobutyric acid) were prepared using 2,2'-bipyridine, 1,10-phenanthroline, and 2-picolylamine ligands: [Cu(2,2'-bipyridine)(ACC)(H2O)](ClO4) (1a), [Cu(1,10-phenanthroline)(ACC)](ClO4) (2a), [Cu(2-picolylamine)(ACC)](ClO4) (3a), and [Cu(2,2'-bipyridine)(AIB)(H2O)](ClO4) (1b). All of the complexes were characterized by X-ray diffraction analysis. The Cu(II)-ACC complexes are able to convert the bound ACC moiety into ethylene in the presence of hydrogen peroxide, in an "ACC-oxidase-like" activity. A few equivalents of base are necessary to deprotonate H2O2 for optimum activity. The presence of dioxygen lowers the yield of ACC conversion into ethylene by the copper(II) complexes. During the course of the reaction of Cu(II)-ACC complexes with H2O2, brown species (EPR silent and lambda max approximately 435 nm) were detected and characterized as being the Cu(I)-ACC complexes that are obtained upon reduction of the corresponding Cu(II) complexes by the deprotonated form of hydrogen peroxide. The geometry of the Cu(I) species was optimized by DFT calculations that reveal a change from square-planar to tetrahedral geometry upon reduction of the copper ion, in accordance with the observed nonreversibility of the redox process. In situ prepared Cu(I)-ACC complexes were also reacted with hydrogen peroxide, and a high level of ethylene formation was obtained. We propose Cu(I)-OOH as a possible active species for the conversion of ACC into ethylene, the structure of which was examined by DFT calculation.

  6. Environmental concentrations of copper, chromium, and arsenic released from a chromated-copper-arsenate-(CCA-C-) treated wetland boardwalk

    Treesearch

    Stan T. Lebow; Daniel Foster

    2005-01-01

    A study was conducted to evaluate environmental accumulation and mobility of total copper, chromium, and arsenic adjacent to a chromated-copper-arsenate-(CCA-C-) treated wetland boardwalk. The study was considered a severe test because it included a large volume of treated wood in a site with high annual rainfall. Soil and sediment samples were collected before...

  7. Microwave-assisted organic acids extraction of chromate copper arsenate (CCA)-treated southern pine

    Treesearch

    Bin Yu; Chung Y. Hse; Todd F. Shupe

    2010-01-01

    The extraction effects of acid concentration, reaction time and temperature in a microwave reactor on recovery of CCA-treated wood were evaluated. Extraction of copper, chromium, and arsenic metals from chromated copper arsenate (CCA)-treated southern pine wood samples with two different organic acids (i.e., acetic acid and oxalic acid) was investigated using a...

  8. WASTE REDUCTION PRACTICES AT TWO CHROMATED COPPER ARSENATE WOOD-TREATING PLANTS

    EPA Science Inventory

    Two chromated copper arsenate (CCA) wood-treating plants were assessed for their waste reduction practices. The objectives of this study were to estimate the amount of hazardous wastes that a well-designed and well-main- tained CCA treatment facility would generate and to iden- t...

  9. Rapid microwave-assisted acid extraction of metals from chromated copper arsenate (CCA)-treated southern pine wood

    Treesearch

    Bin Yu; Chung Y. Hse; Todd F. Shupe

    2009-01-01

    The effects of acid concentration, reaction time, and temperature in a microwave reactor on recovery of CCA-treated wood were evaluated. Extraction of copper, chromium, and arsenic metals from chromated copper arsenate (CCA)-treated southern pine wood samples with three different acids (i.e., acetic acid, oxalic acid, and phosphoric acid) was investigated using in...

  10. Chromated Arsenicals (CCA)

    EPA Pesticide Factsheets

    Chromated copper arsenate (CCA) is a wood preservative pesticide containing chromium, copper, and arsenic that protects wood against termites, fungi, mites and other pests that can degrade or threaten the integrity of wood products.

  11. Rapid microwave-assisted acid extraction of southern pine waste wood to remove metals from chromated copper arsenate (CCA) treatment

    Treesearch

    Chung-Yun Hse; Todd F. Shupe; Bin Yu

    2013-01-01

    Recovery of metals from chromated copper arsenate (CCA)-treated southern pine wood particles was investigated by extraction in a microwave reactor with binary combinations of acetic acid (AA), oxalic acid (OxA), and phosphoric acid (PhA). Use of OxA was not successful, as insoluble copper oxalate complexes impeded copper removal. The combination of OxA and AA also had...

  12. ASSESSING CHILDREN'S EXPOSURES TO THE WOOD PRESERVATIVE CCA (CHROMATED COPPER ARSENATE) ON TREATED PLAYSETS AND DECKS

    EPA Science Inventory

    Concerns have been raised regarding the safety of young children contacting arsenic and chromium residues while playing on and around Chromated Copper Arsenate (CCA) treated wood playground structures and decks. Although CCA registrants voluntarily canceled treated wood for re...

  13. Soil and sediment concentrations of chromium, copper, and arsenic adjacent to a chromated copper arsenate-treated wetland boardwalk

    Treesearch

    Stan Lebow; Daniel Foster

    2010-01-01

    Environmental accumulation of preservative adjacent to a chromated copper arsenate (type C)–treated wetland boardwalk was evaluated. The site is considered a realistic ‘‘worst case’’ because of the large volume of treated wood, low current speeds, high annual rainfall, and environmental sensitivity. Soil and sediment samples were collected before construction and 0.5,...

  14. Assessment of the Environmental Effects Associated With Wooden Bridges Preserved With Creosote, Pentachlorophenol, or Chromated Copper Arsenate

    DOT National Transportation Integrated Search

    2000-09-01

    Timber bridge components are treated with chromated copper arsenate type C (CCA), pentachlorophenol or creosote to preserve the life of the structure from a few years to many decades, resulting in reduced transportation infrastructure costs and incre...

  15. Effect of weathering on chromated copper arsenate (CCA) treated wood : leaching of metal salts and change in water repellency

    Treesearch

    R. Sam Williams; Stan Lebow; Patricia Lebow

    2003-01-01

    Wood pressure-treated with chromated copper arsenate (CCA) wood preservative is commonly used for outdoor construction. Oxides of arsenic, copper, and chromium are bound in the wood by a complex series of chemical reactions, but a small percentage of these compounds are gradually released by leaching and weathering. Recent studies suggest that the release of these...

  16. Mechanical Performance of Nail-Laminated Posts Manufactured from Reclaimed Chromated Copper Arsenate-Treated Decking Lumber

    Treesearch

    John J. Janowiak; Robert H. Falk; Brad A. Gething; John A. Tsirigotis

    2014-01-01

    This study determined the mechanical properties of nail-laminated (nail-lam) posts manufactured from reclaimed chromated copper arsenate (CCA)–treated decking lumber. Though CCA-treated lumber is no longer accepted for use in residential applications, it is permitted in agricultural and industrial applications where health and environmental impacts are deemed to be...

  17. Residual strength and stiffness of lumber from decommissioned chromated copper arsenate-treated southern pine utility poles

    Treesearch

    Cheng Piao; Leslie Groom

    2010-01-01

    The reusability of decommissioned treated wood is primarily dependent on the residual strength of the wood after service. Determining the residual strength can provide useful information for structural design and reuse of the decommissioned treated wood. This study evaluated the residual strength of decommissioned chromated copper arsenate–treated utility pole wood....

  18. Assessment of the environmental effects associated with wooden bridges preserved with creosote, pentachlorophenol, or chromated copper arsenate

    Treesearch

    Kenneth M. Brooks

    Timber bridges provide an economical alternative to concrete and steel structures, particularly in rural areas with light to moderate vehicle traffic. Wooden components of these bridges are treated with chromated copper arsenate type C (CCA), pentachlorophenol, or creosote to prolong the life of the structure from a few years to many decades. This results in reduced...

  19. Bioaccessibility and Solubility of Copper in Copper-Treated Lumber

    EPA Science Inventory

    Micronized copper (MC)-treated lumber is a recent replacement for Chromated Copper Arsenate (CCA) and Ammonium Copper (AC)-treated lumbers; though little is known about the potential risk of copper (Cu) exposure from incidental ingestion of MC-treated wood. The bioaccessibility o...

  20. Fractionation of heavy metals in liquefied chromated copper arsenate (CCA)-treated wood sludge using a modified BCR-sequential extraction procedure

    Treesearch

    Hui Pan; Chung-Yun Hse; Robert Gambrell; Todd F. Shupe

    2009-01-01

    Chromated copper arsenate (CCA)-treated wood was liquefied with polyethylene glycol/glycerin and sulfuric acid. After liquefaction, most CCA metals (98% As, 92% Cr, and 83% Cu) were removed from liquefied CCA-treated wood by precipitation with calcium hydroxide. The original CCA-treated wood and liquefied CCA-treated wood sludge were fractionated by a modified...

  1. Characterization of pyrolytic products obtained from fast pyrolysis of chromated copper arsenate (CCA)- and alkaline copper quaternary compounds (ACQ)-treated wood biomasses.

    PubMed

    Kim, Jae-Young; Kim, Tae-Sung; Eom, In-Yong; Kang, Sung Mo; Cho, Tae-Su; Choi, In Gyu; Choi, Joon Weon

    2012-08-15

    In this study, chromated copper arsenate-treated wood (CCA-W) and alkaline copper quaternary compounds-treated wood (ACQ-W) were subjected to fast pyrolysis at 500°C for ca. 2s to produce bio-oil and char. The physicochemical properties of the pyrolytic products as well as the distribution of heavy metals - arsenic, copper and chrome - during fast pyrolysis were investigated. The water content, viscosity, pH and higher heating value (HHV) of bio-oil from CCA-W were 24.8 wt%, 13.5 cSt, 2.1 and 16 MJ/kg, respectively, whereas those of bio-oil from ACQ-W were 27.9 wt%, 16 cSt, 3.0 and 14.1 MJ/kg, respectively. The yields of bio-oil from CCA-W and ACQ-W were 43.3% and 46.6%, respectively, significantly lower than that of control (61.6%). In the pyrolytic products of CCA-W, the concentrations of arsenic, copper and chromium were determined to be 36.4 wt%, 74.0 wt% and 75.4 wt% in char, respectively, 34.5 wt%, 10.3 wt% and 9.0 wt% in bio-oil, respectively, and 29.0 wt%, 15.7 wt% and 15.5 wt% in gas, respectively. In addition, most of the copper appeared in the char (98.8 wt%) and only a trace amount of copper was detected in the bio-oil (0.2 wt%) produced by ACQ-W. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. A PROBABILISTIC ARSENIC EXPOSURE ASSESSMENT FOR CHILDREN WHO CONTACT CHROMATED COPPER ARSENATE ( CAA )-TREATED PLAYSETS AND DECKS: PART 2 SENSITIVITY AND UNCERTAINTY ANALYSIS

    EPA Science Inventory

    A probabilistic model (SHEDS-Wood) was developed to examine children's exposure and dose to chromated copper arsenate (CCA)-treated wood, as described in Part 1 of this two part paper. This Part 2 paper discusses sensitivity and uncertainty analyses conducted to assess the key m...

  3. Comparative study on liquefaction of creosote and chromated copper arsenate (CCA)-treated wood and untreated southern pine wood: effects of acid catalyst content, liquefaction time, temperature, and phenol to wood ratio

    Treesearch

    Hui Pan; Chung-Yun Hse; Todd F. Shupe

    2009-01-01

    Creosote- and chromated copper arsenate (CCA)-treated wood waste and untreated southern pine wood were liquefied with phenol and sulfuric acid. The effects of sulfuric acid content, liquefaction time, liquefaction temperature, and phenol to wood ratio on liquefaction rate (i.e., wood residue content) were investigated and analyzed by analysis of variance (...

  4. Performance of copper-based wood preservatives in soil bed exposures

    Treesearch

    Stan T. Lebow; Thomas Nilsson; Jeffrey J. Morrell

    Copper-based biocides are widely used to protect wood from biological attack in a variety of environments. Chromated copper arsenate (CCA) is the dominant copper-based preservative for wood protection (J. T. MICKLEWRIGHT, 1989). First developed in India in the 1930s, CCA contains a very effective combination of materials. Copper provides protection against most...

  5. Long-term stake evaluations of waterborne copper systems

    Treesearch

    Stan Lebow; Cherilyn Hatfield; Douglas Crawford; Bessie Woodward

    2003-01-01

    Limitations on the use of chromated copper arsenate (CCA) have heightened interest in use of arsenic-free copper-based alternatives. For decades, the USDA Forest Products Laboratory has been evaluating several of these systems in stake plots. Southern Pine 38- by 89- by 457-mm (1.5- by 3.5- by 18-inch) stakes were treated with varying concentrations of acid copper...

  6. In vitro bioaccessibility of copper azole following simulated dermal transfer from pressure-treated wood

    EPA Science Inventory

    Micronized copper azole (MCA) and micronized copper quaternary are the latest wood preservatives to replace the liquid lkaline copper and chromated copper arsenate preservatives due to concerns over the toxicity or lack of effectiveness of the earlier formulations. Today, the use...

  7. Extraction of hexavalent chromium from chromated copper arsenate treated wood under alkaline conditions.

    PubMed

    Radivojevic, Suzana; Cooper, Paul A

    2008-05-15

    Information on chromium (Cr) oxidation states is essential for the assessment of environmental and health risks associated with the overall life-cycle of chromated copper arsenate (CCA) treated wood products because of differences in toxicity between trivalent [Cr(III)] and hexavalent [Cr(VI)] chromium compounds. Hypothetical Cr(VI) fixation products were investigated in CCA type C treated sawdust of aspen and red pine during or following preservative fixation by extraction with Cr(VI)-specific extractants. Cr(VI) was found only in alkaline extracts of treated wood. A major source of Cr(VI) was method-induced oxidation of fixed Cr(III) during alkaline extraction, as confirmed by demonstrated oxidation of Cr(III) from CrCl3 treated wood. Oxidation of nontoxic and immobile Cr(III) to toxic and mobile Cr(VI) was facilitated by the presence of wood at pH > 8.5. Thermodynamic equilibrium between Cr(III) and Cr(VI) is affected by pH, temperature, rates of dissolution of CrIII) compounds, and oxygen availability. Results of this study recommend against alkaline extraction protocols for determination of Cr(VI) in treated wood. This Cr oxidation mechanism can act as a previously unrecognized route for generation of hazardous Cr(VI) if CCA treated wood is exposed to alkaline conditions during its production, use, or waste management.

  8. Characterization of Cu(II)-reconstituted ACC Oxidase using experimental and theoretical approaches.

    PubMed

    El Bakkali-Tahéri, Nadia; Tachon, Sybille; Orio, Maylis; Bertaina, Sylvain; Martinho, Marlène; Robert, Viviane; Réglier, Marius; Tron, Thierry; Dorlet, Pierre; Simaan, A Jalila

    2017-06-01

    1-Aminocyclopropane-1-carboxylic acid oxidase (ACCO) is a non heme iron(II) containing enzyme that catalyzes the final step of the ethylene biosynthesis in plants. The iron(II) ion is bound in a facial triad composed of two histidines and one aspartate (H177, D179 and H234). Several active site variants were generated to provide alternate binding motifs and the enzymes were reconstituted with copper(II). Continuous wave (cw) and pulsed Electron Paramagnetic Resonance (EPR) spectroscopies as well as Density Functional Theory (DFT) calculations were performed and models for the copper(II) binding sites were deduced. In all investigated enzymes, the copper ion is equatorially coordinated by the two histidine residues (H177 and H234) and probably two water molecules. The copper-containing enzymes are inactive, even when hydrogen peroxide is used in peroxide shunt approach. EPR experiments and DFT calculations were undertaken to investigate substrate's (ACC) binding on the copper ion and the results were used to rationalize the lack of copper-mediated activity. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Adhesive bonding of wood treated with ACQ and copper azole preservatives

    Treesearch

    Linda F. Lorenz; Charles Frihart

    2006-01-01

    Treated wood has generally been more difficult to bond than untreated wood for a variety of reasons. Alkaline copper quat (ACQ) and copper azole (CA-B), the most prominent substitutes for chromated copper arsenate (CCA), are difficult to bond consistently. Using a phenol-resorcinol- formaldehyde (PRF) adhesive formulated for bonding to CCA-treated wood, we examined the...

  10. Chemical-specific health consultation for chromated copper arsenate chemical mixture: port of Djibouti.

    PubMed

    Chou, Selene; Colman, Joan; Tylenda, Carolyn; De Rosa, Christopher

    2007-05-01

    The Agency for Toxic Substances and Disease Registry (ATSDR) prepared this health consultation to provide support for assessing the public health implications of hazardous chemical exposure, primarily through drinking water, related to releases of chromated copper arsenate (CCA) in the port of Djibouti. CCA from a shipment, apparently intended for treating electric poles, is leaking into the soil in the port area. CCA is a pesticide used to protect wood against decay-causing organisms. This mixture commonly contains chromium(VI) (hexavalent chromium) as chromic acid, arsenic(V) (pentavalent arsenic) as arsenic pentoxide and copper (II) (divalent copper) as cupric oxide, often in an aqueous solution or concentrate. Experimental studies of the fate of CCA in soil and monitoring studies of wood-preserving sites where CCA was spilled on the soil indicate that the chromium(VI), arsenic and copper components of CCA can leach from soil into groundwater and surface water. In addition, at CCA wood-preserving sites, substantial concentrations of chromium(VI), arsenic and copper remained in the soil and were leachable into water four years after the use of CCA was discontinued, suggesting prolonged persistence in soil, with continued potential for leaching. The degree of leaching depended on soil composition and the extent of soil contamination with CCA. In general, leaching was highest for chromium(VI), intermediate for arsenic and lowest for copper. Thus, the potential for contamination of sources of drinking water exists. Although arsenic that is leached from CCA-contaminated soil into surface water may accumulate in the tissues of fish and shellfish, most of the arsenic in these animals will be in a form (often called fish arsenic) that is less harmful. Copper, which leaches less readily than the other components, can accumulate in tissues of mussels and oysters. Chromium is not likely to accumulate in the tissues of fish and shellfish. Limited studies of air

  11. Genetic Profiling Reveals Cross-Contamination and Misidentification of 6 Adenoid Cystic Carcinoma Cell Lines: ACC2, ACC3, ACCM, ACCNS, ACCS and CAC2

    PubMed Central

    Phuchareon, Janyaporn; Ohta, Yoshihito; Woo, Jonathan M.; Eisele, David W.; Tetsu, Osamu

    2009-01-01

    Adenoid cystic carcinoma (ACC) is the second most common malignant neoplasm of the salivary glands. Most patients survive more than 5 years after surgery and postoperative radiation therapy. The 10 year survival rate, however, drops to 40%, due to locoregional recurrences and distant metastases. Improving long-term survival in ACC requires the development of more effective systemic therapies based on a better understanding of the biologic behavior of ACC. Much preclinical research in this field involves the use of cultured cells and, to date, several ACC cell lines have been established. Authentication of these cell lines, however, has not been reported. We performed DNA fingerprint analysis on six ACC cell lines using short tandem repeat (STR) examinations and found that all six cell lines had been contaminated with other cells. ACC2, ACC3, and ACCM were determined to be cervical cancer cells (HeLa cells), whereas the ACCS cell line was composed of T24 urinary bladder cancer cells. ACCNS and CAC2 cells were contaminated with cells derived from non-human mammalian species: the cells labeled ACCNS were mouse cells and the CAC2 cells were rat cells. These observations suggest that future studies using ACC cell lines should include cell line authentication to avoid the use of contaminated or non-human cells. PMID:19557180

  12. Chemical Speciation and Bioaccessibility of Arsenic and Chromiumin Chromated Copper Arsenate-Treated Wood and Soils

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nico, Peter S.; Ruby, Michael V.; Lowney, Yvette W.

    This research compares the As and Cr chemistry ofdislodgeable residues from Chromated Copper Arsenate (CCA)-treated woodcollected by two different techniques (directly from the board surfaceeither by rubbing with a soft bristle brush or from human hands aftercontact with CCA-treated wood), and demonstrates that these materials areequivalent in terms of the chemical form and bonding of As and Cr and interms of the As leaching behavior. This finding links the extensivechemical characterization and bioavailability testing that has been donepreviously on the brush-removed residue to a material that is derivedfrom human skin contact with CCA-treated wood. Additionally, thisresearch characterizes the arsenic presentmore » in biological fluids (sweatand simulated gastric fluid) following contact with these residues. Thedata demonstrate that in biological fluids, the arsenic is presentprimarily as free arsenate ions.Arsenic-containing soils were alsoextracted into human sweat to evaluate the potential for arsenicdissolution from soils at the skin surface. For soils from field sites,only a small fraction of the total arsenic is soluble in sweat. Based oncomparisons to reference materials that have been used in in vivo dermalabsorption studies, these findings suggest that the actual relativebioavailability via dermal absorption of As from CCA-residues and soilmay be well below the current default value of 3 percent used by U.S.EPA.« less

  13. Copper tolerance of brown-rot fungi : oxalic acid production in southern pine treated with arsenic-free preservatives

    Treesearch

    Frederick Green; Carol A. Clausen

    2005-01-01

    The voluntary withdrawal of chromated copper arsenate (CCA)-treated wood from most residential applications has increased the use of non-arsenical copper-based organic wood preservatives. Because the arsenic component of CCA controlled copper tolerant fungi, scientists have renewed interest in and concern about the decay capacity in the important copper-tolerant group...

  14. Ground-contact durability of wood treated with borax-copper preservative

    Treesearch

    Stan T. Lebow; Bessie Woodward; Patricia K. Lebow

    2007-01-01

    This study evaluated the ability of a borax-copper(BC) preservative to protect wood exposed in ground contact. Southern pine sapwood stakes were pressure-treated with 0.9%, 1.4%, 2.3%, and 4.7% BC solution concentrations and placed into the ground at test sites near Mississippi, or Madison, Wisconsin. Untreated stakes and stakes treated with 1% chromated copper...

  15. Toxicity of chromated copper arsenate (CCA)-treated wood to non-target marine fouling communities in Langstone Harbour, Portsmouth, UK.

    PubMed

    Brown, C J; Eaton, R A

    2001-04-01

    The effect of the anti-marine-borer timber preservative chromated copper arsenate (CCA) (a pressure impregnated solution of copper, chromium and arsenic compounds) on non-target marine fouling animals was investigated during a subtidal exposure trial. Panels of Scots pine treated to target retentions of 12, 24 and 48 kg CCA per m-3 of wood, plus untreated controls were submerged at a coastal site on the south coast of the UK for 6, 12 and 18 months. After each exposure period the fouling communities that formed on the surface of panels were assessed both qualitatively and quantitatively. Community structure was similar on panels treated to the three CCA loadings, but was significantly different from community structure on untreated panels. The total number of species (species richness) was similar on all panels, although the number of individual organisms attached to the surface of panels was significantly higher on CCA-treated panels than on untreated panels. k-dominance curves revealed that the difference in numbers of individuals between CCA-treated and untreated panels was caused by higher numbers of the dominant species (Elminius modestus, Hydroides ezoensis, and Electra pilosa) on CCA-treated panels. Other species were present in similar numbers on panels of all treatments. Results indicate that there are no detrimental toxic effects to epibiota caused by the presence of CCA preservative within the matrix of the wood at any of the treatment levels. Differences in community structure between CCA-treated and untreated panels may be due to enhanced larval settlement on CCA-treated timber by some species as a result of modifications to the surface properties of the timber by the CCA preservative.

  16. EVALUATION OF THE EFFECTIVENESS OF COATINGS IN REDUCING DISLODGEABLE ARSENIC, CHROMIUM, AND COPPER FROM CCA-TREATED WOOD

    EPA Science Inventory

    This is a 2 year study designed to evaluate the effectiveness of a variety of deck sealants in reducing or eliminating potential exposure to arsenic, chromium, and copper from chromated copper arsenate-treated wood used in residential settings, like decks and playsets.

  17. A colorimetric assay of 1-aminocyclopropane-1-carboxylate (ACC) based on ninhydrin reaction for rapid screening of bacteria containing ACC deaminase.

    PubMed

    Li, Z; Chang, S; Lin, L; Li, Y; An, Q

    2011-08-01

    1-Aminocyclopropane-1-carboxylate (ACC) deaminase activity is an efficient marker for bacteria to promote plant growth by lowering ethylene levels in plants. We aim to develop a method for rapidly screening bacteria containing ACC deaminase, based on a colorimetric ninhydrin assay of ACC. A reliable colorimetric ninhydrin assay was developed to quantify ACC using heat-resistant polypropylene chimney-top 96-well PCR plates, having the wells evenly heated in boiling water, preventing accidental contamination from boiling water and limiting evaporation. With this method to measure bacterial consumption of ACC, 44 ACC-utilizing bacterial isolates were rapidly screened out from 311 bacterial isolates that were able to grow on minimal media containing ACC as the sole nitrogen source. The 44 ACC-utilizing bacterial isolates showed ACC deaminase activities and belonged to the genus Burkholderia, Pseudomonas or Herbaspirillum. Determination of bacterial ACC consumption by the PCR-plate ninhydrin-ACC assay is a rapid and efficient method for screening bacteria containing ACC deaminase from a large number of bacterial isolates. The PCR-plate ninhydrin-ACC assay extends the utility of the ninhydrin reaction and enables a rapid screening of bacteria containing ACC deaminase from large numbers of bacterial isolates. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

  18. Camera processing with chromatic aberration.

    PubMed

    Korneliussen, Jan Tore; Hirakawa, Keigo

    2014-10-01

    Since the refractive index of materials commonly used for lens depends on the wavelengths of light, practical camera optics fail to converge light to a single point on an image plane. Known as chromatic aberration, this phenomenon distorts image details by introducing magnification error, defocus blur, and color fringes. Though achromatic and apochromatic lens designs reduce chromatic aberration to a degree, they are complex and expensive and they do not offer a perfect correction. In this paper, we propose a new postcapture processing scheme designed to overcome these problems computationally. Specifically, the proposed solution is comprised of chromatic aberration-tolerant demosaicking algorithm and post-demosaicking chromatic aberration correction. Experiments with simulated and real sensor data verify that the chromatic aberration is effectively corrected.

  19. Evaluating landfill disposal of chromated copper arsenate (CCA) treated wood and potential effects on groundwater: evidence from Florida.

    PubMed

    Saxe, Jennifer K; Wannamaker, Eric J; Conklin, Scott W; Shupe, Todd F; Beck, Barbara D

    2007-01-01

    Chromated copper arsenate (CCA) treated wood has been used for more than 50 years. Recent attention has been focused on appropriate disposal of CCA-treated wood when its service life ends. Groups in the US and Europe concerned with the possibility of arsenic migration to groundwater from disposed CCA-treated wood have proposed that consumers be required to dispose of the wood as a hazardous waste, in the most protective of landfills. We examined available data for evidence of arsenic migration from unlined construction and demolition (C&D) debris landfills in Florida, where CCA-treated wood is disposed. Florida was chosen because soil, groundwater, landfill design, weather, and levels of CCA-treated wood use make the state a uniquely sensitive indicator for observing arsenic migration from CCA-treated wood disposal sites, should it occur. We developed and quality-checked a CCA-treated wood disposal model to estimate the amount of wood and associated arsenic disposed. By 2000, an estimated 13 million kg of arsenic in CCA-treated wood was disposed in Florida; however, groundwater monitoring data do not indicate that arsenic is migrating from unlined C&D landfills. Our results provide evidence that highly stringent regulation of CCA-treated wood disposal, such as treatment as a hazardous waste, is unnecessary.

  20. Chromatic induction in space and time.

    PubMed

    Coia, Andrew J; Shevell, Steven K

    2018-04-01

    The color appearance of a light depends on variation in the complete visual field over both space and time. In the spatial domain, a chromatic stimulus within a patterned chromatic surround can appear a different hue than the same stimulus within a uniform surround. In the temporal domain, a stimulus presented as an element of a continuously changing chromaticity can appear a different color compared to the identical stimulus, presented simultaneously but viewed alone. This is the flash-lag effect for color, which has an analog in the domain of motion: a pulsed object seen alone can appear to lag behind an identical pulsed object that is an element of a motion sequence. Studies of the flash-lag effect for motion have considered whether it is mediated by a neural representation for the moving physical stimulus or, alternatively, for the perceived motion. The current study addresses this question for the flash-lag effect for color by testing whether the color flash lag depends on a representation of only the changing chromatic stimulus or, alternatively, its color percept, which can be altered by chromatic induction. baseline measurements for spatial chromatic induction determined the chromaticity of a flashed ring within a uniform surround that matched a flashed ring within a patterned surround. Baseline measurements for the color flash-lag effect determined the chromaticity of a pulsed ring presented alone (within a uniform surround) that matched a pulsed ring presented in a sequence of changing chromaticity over time (also within a uniform surround). Finally, the main experiments combined chromatic induction from a patterned surround and the flash-lag effect, in three conditions: (1) both the changing and pulsed rings were within a patterned chromatic surround; (2) the changing ring was within a patterned surround and the pulsed ring within a uniform surround; and (3) the changing ring was within a uniform surround and the pulsed ring within a patterned surround

  1. Isolating metal-tolerant bacteria capable of removing copper, chromium, and arsenic from treated wood

    Treesearch

    Carol A. Clausen

    2000-01-01

    Bioremediation of chromated copper arsenate-treated waste wood with one or more metal-tolerant bacteria is a potential method of naturally releasing metals from treated wood fibre. Sampling eight environments with elevated levels of copper, chromium, and arsenic resulted in the isolation of 28 bacteria with the capability of releasing one or more of the components from...

  2. Interaction of copper wood preservatives and adhesives

    Treesearch

    Charles R. Frihart

    2003-01-01

    Compared to other substrates, wood is generally easy to bond. However, adhesion is diminished when the wood surface is covered by chemicals, whether natural oils and resins or added chemicals. Among the chemicals added to wood are fire retardants and wood preservatives. Chromated copper arsenate (CCA) has been widely used to protect wood against rot and termites, but...

  3. Chromatic interocular-switch rivalry.

    PubMed

    Christiansen, Jens H; D'Antona, Anthony D; Shevell, Steven K

    2017-05-01

    Interocular-switch rivalry (also known as stimulus rivalry) is a kind of binocular rivalry in which two rivalrous images are swapped between the eyes several times a second. The result is stable periods of one image and then the other, with stable intervals that span many eye swaps (Logothetis, Leopold, & Sheinberg, 1996). Previous work used this close kin of binocular rivalry with rivalrous forms. Experiments here test whether chromatic interocular-switch rivalry, in which the swapped stimuli differ in only chromaticity, results in slow alternation between two colors. Swapping equiluminant rivalrous chromaticities at 3.75 Hz resulted in slow perceptual color alternation, with one or the other color often continuously visible for two seconds or longer (during which there were 15+ eye swaps). A well-known theory for sustained percepts from interocular-switch rivalry with form is inhibitory competition between binocular neurons driven by monocular neurons with matched orientation tuning in each eye; such binocular neurons would produce a stable response when a given orientation is swapped between the eyes. A similar model can account for the percepts here from chromatic interocular-switch rivalry and is underpinned by the neurophysiological finding that color-preferring binocular neurons are driven by monocular neurons from each eye with well-matched chromatic selectivity (Peirce, Solomon, Forte, & Lennie, 2008). In contrast to chromatic interocular-switch rivalry, luminance interocular-switch rivalry with swapped stimuli that differ in only luminance did not result in slowly alternating percepts of different brightnesses.

  4. Chromatic interocular-switch rivalry

    PubMed Central

    Christiansen, Jens H.; D'Antona, Anthony D.; Shevell, Steven K.

    2017-01-01

    Interocular-switch rivalry (also known as stimulus rivalry) is a kind of binocular rivalry in which two rivalrous images are swapped between the eyes several times a second. The result is stable periods of one image and then the other, with stable intervals that span many eye swaps (Logothetis, Leopold, & Sheinberg, 1996). Previous work used this close kin of binocular rivalry with rivalrous forms. Experiments here test whether chromatic interocular-switch rivalry, in which the swapped stimuli differ in only chromaticity, results in slow alternation between two colors. Swapping equiluminant rivalrous chromaticities at 3.75 Hz resulted in slow perceptual color alternation, with one or the other color often continuously visible for two seconds or longer (during which there were 15+ eye swaps). A well-known theory for sustained percepts from interocular-switch rivalry with form is inhibitory competition between binocular neurons driven by monocular neurons with matched orientation tuning in each eye; such binocular neurons would produce a stable response when a given orientation is swapped between the eyes. A similar model can account for the percepts here from chromatic interocular-switch rivalry and is underpinned by the neurophysiological finding that color-preferring binocular neurons are driven by monocular neurons from each eye with well-matched chromatic selectivity (Peirce, Solomon, Forte, & Lennie, 2008). In contrast to chromatic interocular-switch rivalry, luminance interocular-switch rivalry with swapped stimuli that differ in only luminance did not result in slowly alternating percepts of different brightnesses. PMID:28510624

  5. EVALUATION OF THE EFFECTIVENESS OF COATINGS IN REDUCING DISLODGEABLE ARSENIC, CHROMIUM, AND COPPER FROM CCA TREATED WOOD; FINAL REPORT

    EPA Science Inventory

    EPA conducted a study to evaluate the effect of coatings on dislodgeable arsenic, chromium, and copper residues on the surfaces of chromated copper arsenate (CAA) treated wood. Dislodgeable CCA, determined by wipe sampling the wood surfaces, was the primary evaluation criterion f...

  6. Does the chromatic Mach bands effect exist?

    PubMed

    Tsofe, Avital; Spitzer, Hedva; Einav, Shmuel

    2009-06-30

    The achromatic Mach bands effect is a well-known visual illusion, discovered over a hundred years ago. This effect has been investigated thoroughly, mainly for its brightness aspect. The existence of Chromatic Mach bands, however, has been disputed. In recent years it has been reported that Chromatic Mach bands are not perceived under controlled iso-luminance conditions. However, here we show that a variety of Chromatic Mach bands, consisting of chromatic and achromatic regions, separated by a saturation ramp, can be clearly perceived under iso-luminance and iso-brightness conditions. In this study, observers' eye movements were recorded under iso-brightness conditions. Several observers were tested for their ability to perceive the Chromatic Mach bands effect and its magnitude, across different cardinal and non-cardinal Chromatic Mach bands stimuli. A computational model of color adaptation, which predicted color induction and color constancy, successfully predicts this variation of Chromatic Mach bands. This has been tested by measuring the distance of the data points from the "achromatic point" and by calculating the shift of the data points from predicted complementary lines. The results suggest that the Chromatic Mach bands effect is a specific chromatic induction effect.

  7. Psychophysical chromatic mechanisms in macaque monkey.

    PubMed

    Stoughton, Cleo M; Lafer-Sousa, Rosa; Gagin, Galina; Conway, Bevil R

    2012-10-24

    Chromatic mechanisms have been studied extensively with psychophysical techniques in humans, but the number and nature of the mechanisms are still controversial. Appeals to monkey neurophysiology are often used to sort out the competing claims and to test hypotheses arising from the experiments in humans, but psychophysical chromatic mechanisms have never been assessed in monkeys. Here we address this issue by measuring color-detection thresholds in monkeys before and after chromatic adaptation, employing a standard approach used to determine chromatic mechanisms in humans. We conducted separate experiments using adaptation configured as either flickering full-field colors or heterochromatic gratings. Full-field colors would favor activity within the visual system at or before the arrival of retinal signals to V1, before the spatial transformation of color signals by the cortex. Conversely, gratings would favor activity within the cortex where neurons are often sensitive to spatial chromatic structure. Detection thresholds were selectively elevated for the colors of full-field adaptation when it modulated along either of the two cardinal chromatic axes that define cone-opponent color space [L vs M or S vs (L + M)], providing evidence for two privileged cardinal chromatic mechanisms implemented early in the visual-processing hierarchy. Adaptation with gratings produced elevated thresholds for colors of the adaptation regardless of its chromatic makeup, suggesting a cortical representation comprised of multiple higher-order mechanisms each selective for a different direction in color space. The results suggest that color is represented by two cardinal channels early in the processing hierarchy and many chromatic channels in brain regions closer to perceptual readout.

  8. ACC Effectiveness Review, 1999-2002.

    ERIC Educational Resources Information Center

    Wallace, Roslyn, Ed.

    2002-01-01

    These newsletters on Institutional Effectiveness (IE) at Austin Community College (ACC) in Texas include the following articles: (1) "The 'Fast Track'...Students Say It Works!" (2) "Are Students Successfully Completing Distance Learning Courses at ACC?" (3) "Tracking Transfers"; (4) "Math Pilot: Study Skills…

  9. 24 CFR 982.154 - ACC reserve account.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false ACC reserve account. 982.154... and PHA Administration of Program § 982.154 ACC reserve account. (a) HUD may establish and maintain an unfunded reserve account for the PHA program from available budget authority under the consolidated ACC...

  10. 24 CFR 982.154 - ACC reserve account.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false ACC reserve account. 982.154... and PHA Administration of Program § 982.154 ACC reserve account. (a) HUD may establish and maintain an unfunded reserve account for the PHA program from available budget authority under the consolidated ACC...

  11. Copper-resistant halophilic bacterium isolated from the polluted Maruit Lake, Egypt.

    PubMed

    Osman, O; Tanguichi, H; Ikeda, K; Park, P; Tanabe-Hosoi, S; Nagata, S

    2010-04-01

    To isolate and characterize copper-resistant halophilic bacteria from the polluted Maruit Lake, Egypt and identify the role of plasmids in toxic metal resistance. We isolated strain MA2, showing high copper resistance up to the 1.5 mmol l(-1) concentration; it was also resistant to other metals such as nickel, cobalt and zinc and a group of antibiotics. Partial 16S rRNA analysis revealed that strain MA2 belonged to the genus Halomonas. Copper uptake, measured by atomic absorption spectrophotometery, was higher in the absence of NaCl than in the presence of 0.5-1.0 mol l(-1) NaCl during 5-15 min of incubation. Cell fractionation and electron microscopic observation clarified that most of the copper accumulated in the outer membrane and periplasmic fractions of the cells. Plasmid screening yielded two plasmids: pMA21 (11 kb) and pMA22 (5 kb). Plasmid curing resulted in a strain that lost both the plasmids and was sensitive to cobalt and chromate but not copper, nickel and zinc. This cured strain also showed weak growth in the presence of 0.5-1.0 mol l(-1) NaCl. Partial sequencing of both plasmids led to the identification of different toxic metals transporters but copper transporters were not identified. The highest cell viability was found in the presence of 1.0 mol l(-1) NaCl at different copper concentrations, and copper uptake was optimal in the absence of NaCl. Plasmid pMA21 encoded chromate, cobalt, zinc and cadmium transporters, whereas pMA22 encoded specific zinc and RND (resistance, nodulation, cell division) efflux transporters as well as different kinds of metabolic enzymes. Copper resistance was mainly incorporated in the chromosome. Strain MA2 is a fast and efficient tool for copper bioremediation and the isolated plasmids show significant characteristics of both toxic metal and antibiotic resistance.

  12. BIOAVAILABILITY OF ARSENIC, CHROMIUM, AND COPPER FROM CCA CONTAMINATED SOILS AND DUSTS

    EPA Science Inventory

    It is estimated that 70% of single family homes have pressure-treated wood decks or porches and 14% of playground equipment uses pressure-treated wood. This popular form of wood contains chromated copper arsenate (CCA), which is an antimicrobial pesticide and is currently underg...

  13. BIOAVAILABILITY OF ARSENIC, CHROMIUM, AND COPPER FOR CCA CONTAMINATED SOILS AND DUST

    EPA Science Inventory

    It is estimated that 70% of single family homes have pressure-treated wood decks or porches and 14% of playground equipment uses pressure-treated wood. This popular form of wood contains chromated copper arsenate (CCA), which is an antimicrobial pesticide and is currently underg...

  14. An alternate to chromate conversion coatings for the corrosion protection of aluminum 2024-T3

    NASA Astrophysics Data System (ADS)

    Guo, Ruiguang

    Corrosion of high-strength aluminum alloys used for airspace application is an expensive and serious problem. The most significant environmental factor contributing to the corrosion of these alloys is water condensed from humid air and contaminated with soluble chloride salts. The Al 2024 series used for aircraft are particularly susceptible to corrosion in aqueous chloride solutions due to alloying constituents such as copper and other impurities. Chromates are efficient inhibitors of corrosion of aluminum in near neutral aqueous environments containing aggressive anions such as chlorides. Usually, aluminum alloys are initially protected by chromate conversion coatings. Additional polymer coatings are sometimes added during exposure to corrosive atmospheres such as marine environments. Although chromate coatings are widely used, they require the use of noxious solutions, so they have always presented effluent disposal problems. There are health and safety concerns over the use of chromates due to their toxicity and carcinogenic nature and, as a consequence, the environmental and health risks associated with the use of such coatings will be restricted in the future. It was these health and safety concerns that led to the development of alternative non-toxic coating processes with comparable adhesion properties and corrosion protection. A variety of process technologies are under development and are vying for acceptance in industrial markets. As an alternate conversion coating, a new titanate conversion coating was systematically researched and developed. Research concentrated on producing passive surfaces from a simple titanate solution using an immersion process. The corrosion resistance of the treated surface has been evaluated using simple, rapid electrochemical techniques as well as a more long-term salt spray test. Passivation by titanate conversion treatment exhibits many similarities to chromate conversion treatment. Based on this study of corrosion

  15. Chromate Dermatitis from Paint

    PubMed Central

    Engel, H. O.; Calnan, C. D.

    1963-01-01

    Among 250 workers engaged on wet sandpapering of primer paint on car bodies 65 developed a contact dermatitis. The average latent period before dermatitis developed was 4·6 months: only 60% of the patients made a completely satisfactory recovery. The average duration of dermatitis was 5·3 months. Two thirds of the men used one of two barrier creams supplied, while one third used none. Routine patch testing showed that the majority was allergic to chromate. It was found that a primer paint contained zinc chromate, which had been introduced into the paint by the manufacturers shortly before the first cases occurred. Removal of chromate from the paint resulted in a prompt cessation of new cases of dermatitis. Images PMID:14046155

  16. Cement-Induced Chromate Occupational Allergic Contact Dermatitis.

    PubMed

    Kridin, Khalaf; Bergman, Reuven; Khamaisi, Mogher; Zelber-Sagi, Shira; Weltfriend, Sara

    2016-01-01

    Hexavalent chromium in cement is a common cause of occupational allergic contact dermatitis (OACD). Analysis of patch test data during 1999 to 2013 was done. Patients with cement-induced chromate OACD filled the Dermatology Life Quality Index, graded 1 to 5. Of 4846 consecutive patients who were patch tested, 146 (3%) were chromate-sensitive. Of 46 (31.5%) who presented with chromate OACD, 27 (59%) had cement-induced chromate OACD. The proportion of chromate-sensitive patients with clinically relevant cement exposure increased from 7.7% in 2002 to 2004 to 28.7% in 2011 to 2013 (P = 0.04). The median age of presentation was younger than for other chromate-sensitive patients (32 vs 42 years). Hand eczema (88.9%) was the most frequent clinical presentation. Of the 27 with cement-induced chromate OACD, 21 (77.8%) had ongoing dermatitis at the time of the review. Although 14/27 (51.9%) changed their occupation to avoid exposure to cement, symptoms persisted in 9/14 (64.3%). Prolonged exposure to cement before development of symptoms was associated with chronicity. All the symptomatic patients experienced at least a moderate effect on their quality of life (grade 3 or higher on the Dermatology Life Quality Index). We recommend the adoption of the European legislation in Israel, to reduce the prevalence of chromate OACD from cement.

  17. Chromated copper arsenate-treated fence posts in the agronomic landscape: soil properties controlling arsenic speciation and spatial distribution.

    PubMed

    Schwer Iii, Donald R; McNear, David H

    2011-01-01

    Soils adjacent to chromated copper arsenate (CCA)-treated fence posts along a fence line transecting different soil series, parent material, drainage classes, and slope were used to determine which soil properties had the most influence on As spatial distribution and speciation. Metal distribution was evaluated at macroscopic (total metal concentration contour maps) and microscopic scales (micro-synchrotron X-ray fluorescence maps), As speciation was determined using extended X-ray absorption fine structure spectroscopy, and redox status and a myriad of other basic soil properties were elucidated. All geochemical parameters measured point to a condition in which the mobilization of As becomes more favorable moving down the topographic gradient, likely resulting through competition (Meh-P, SOM), neutral or slightly basic pH, and redox conditions that are favorable for As mobilization (higher Fe(II) and total-Fe concentrations in water extracts). On the landscape scale, with hundreds of kilometers of fence, the arsenic loading into the soil can be substantial (∼8-12 kg km). Although a significant amount of the As is stable, extended use of CCA-treated wood has resulted in elevated As concentrations in the local environment, increasing the risk of exposure and ecosystem perturbation. Therefore, a move toward arsenic-free alternatives in agricultural applications for which it is currently permitted should be considered. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  18. Chromatic induction from surrounding stimuli under perceptual suppression.

    PubMed

    Horiuchi, Koji; Kuriki, Ichiro; Tokunaga, Rumi; Matsumiya, Kazumichi; Shioiri, Satoshi

    2014-11-01

    The appearance of colors can be affected by their spatiotemporal context. The shift in color appearance according to the surrounding colors is called color induction or chromatic induction; in particular, the shift in opponent color of the surround is called chromatic contrast. To investigate whether chromatic induction occurs even when the chromatic surround is imperceptible, we measured chromatic induction during interocular suppression. A multicolor or uniform color field was presented as the surround stimulus, and a colored continuous flash suppression (CFS) stimulus was presented to the dominant eye of each subject. The subjects were asked to report the appearance of the test field only when the stationary surround stimulus is invisible by interocular suppression with CFS. The resulting shifts in color appearance due to chromatic induction were significant even under the conditions of interocular suppression for all surround stimuli. The magnitude of chromatic induction differed with the surround conditions, and this difference was preserved regardless of the viewing conditions. The chromatic induction effect was reduced by CFS, in proportion to the magnitude of chromatic induction under natural (i.e., no-CFS) viewing conditions. According to an analysis with linear model fitting, we revealed the presence of at least two kinds of subprocesses for chromatic induction that reside at higher and lower levels than the site of interocular suppression. One mechanism yields different degrees of chromatic induction based on the complexity of the surround, which is unaffected by interocular suppression, while the other mechanism changes its output with interocular suppression acting as a gain control. Our results imply that the total chromatic induction effect is achieved via a linear summation of outputs from mechanisms that reside at different levels of visual processing.

  19. Three-dimensional shape perception from chromatic orientation flows

    PubMed Central

    Zaidi, Qasim; Li, Andrea

    2010-01-01

    The role of chromatic information in 3-D shape perception is controversial. We resolve this controversy by showing that chromatic orientation flows are sufficient for accurate perception of 3-D shape. Chromatic flows required less cone contrast to convey shape than did achromatic flows, thus ruling out luminance artifacts as a problem. Luminance artifacts were also ruled out by a protanope’s inability to see 3-D shape from chromatic flows. Since chromatic orientation flows can only be extracted from retinal images by neurons that are responsive to color modulations and selective for orientation, the psychophysical results also resolve the controversy over the existence of such neurons. In addition, we show that identification of 3-D shapes from chromatic flows can be masked by luminance modulations, indicating that it is subserved by orientation-tuned neurons sensitive to both chromatic and luminance modulations. PMID:16961963

  20. Lattice QCD simulations using the OpenACC platform

    NASA Astrophysics Data System (ADS)

    Majumdar, Pushan

    2016-10-01

    In this article we will explore the OpenACC platform for programming Graphics Processing Units (GPUs). The OpenACC platform offers a directive based programming model for GPUs which avoids the detailed data flow control and memory management necessary in a CUDA programming environment. In the OpenACC model, programs can be written in high level languages with OpenMP like directives. We present some examples of QCD simulation codes using OpenACC and discuss their performance on the Fermi and Kepler GPUs.

  1. Anti-forensics of chromatic aberration

    NASA Astrophysics Data System (ADS)

    Mayer, Owen; Stamm, Matthew C.

    2015-03-01

    Over the past decade, a number of information forensic techniques have been developed to identify digital image manipulation and falsification. Recent research has shown, however, that an intelligent forger can use anti-forensic countermeasures to disguise their forgeries. In this paper, an anti-forensic technique is proposed to falsify the lateral chromatic aberration present in a digital image. Lateral chromatic aberration corresponds to the relative contraction or expansion between an image's color channels that occurs due to a lens's inability to focus all wavelengths of light on the same point. Previous work has used localized inconsistencies in an image's chromatic aberration to expose cut-and-paste image forgeries. The anti-forensic technique presented in this paper operates by estimating the expected lateral chromatic aberration at an image location, then removing deviations from this estimate caused by tampering or falsification. Experimental results are presented that demonstrate that our anti-forensic technique can be used to effectively disguise evidence of an image forgery.

  2. Thick lens chromatic effective focal length variation versus bending

    NASA Astrophysics Data System (ADS)

    Sparrold, Scott

    2017-11-01

    Longitudinal chromatic aberration (LCA) can limit the optical performance in refractive optical systems. Understanding a singlet's chromatic change of effective focal leads to insights and methods to control LCA. Long established, first order theory, shows the chromatic change in focal length for a zero thickness lens is proportional to it's focal length divided by the lens V number or inverse dispersion. This work presents the derivation of an equation for a thick singlet's chromatic change in effective focal length as a function of center thickness, t, dispersion, V, index of refraction, n, and the Coddington shape factor, K. A plot of bending versus chromatic focal length variation is presented. Lens thickness does not influence chromatic variation of effective focal length for a convex plano or plano convex lens. A lens's center thickness'influence on chromatic focal length variation is more pronounced for lower indices of refraction.

  3. The Impact Of Multimode Fiber Chromatic Dispersion On Data Communications

    NASA Astrophysics Data System (ADS)

    Hackert, Michael J.

    1990-01-01

    Capability for the lowest cost is the goal of contemporary communications managers. With all of the competitive pressures that modern businesses are experiencing these days, communications needs must be met with the most information carrying capacity for the lowest cost. Optical fiber communication systems meet these requirements while providing reliability, system integrity, and potential future upgradability. Consequently, optical fiber is finding numerous applications in addition to its traditional telephony plant. Fiber based systems are meeting these requirements in building networks and computer interconnects at a lower cost than copper based systems. A fiber type being chosen by industry to meet these needs in standard systems such as FDDI, is multimode fiber. Multimode fiber systems offer cost advantages over single-mode fiber through lower fiber connection costs. Also, system designers can gain savings by using low cost, high reliability, wide spectral width sources such as LEDs instead of lasers and by operating at higher bit rates than used for multimode systems in the past. However, in order to maximize the cost savings while ensuring the system will operate as intended, the chromatic dispersion of the fiber must be taken into account. This paper explains how to do that and shows how to calculate multimode chromatic dispersion for each of the standard fiber sizes (50 μm, 62.5 μm, 85 μm, and 100μm core diameter).

  4. Third-rank chromatic aberrations of electron lenses.

    PubMed

    Liu, Zhixiong

    2018-02-01

    In this paper the third-rank chromatic aberration coefficients of round electron lenses are analytically derived and numerically calculated by Mathematica. Furthermore, the numerical results are cross-checked by the differential algebraic (DA) method, which verifies that all the formulas for the third-rank chromatic aberration coefficients are completely correct. It is hoped that this work would be helpful for further chromatic aberration correction in electron microscopy. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Understanding and controlling chromaticity shift in LED devices

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Davis, Lynn; Mills, Karmann; Lamvik, Michael

    Chromaticity shift in light-emitting diode (LED) devices arises from multiple mechanisms, and at least five different chromaticity shift modes (CSMs) have been identified to date. This paper focuses on the impacts of irreversible phosphor degradation as a cause of chromaticity shifts in LED devices. The nitride phosphors used to produce warm white LEDs are especially vulnerable to degradation due to thermal and chemical effects such as reactions with oxygen and water. As a result, LED devices utilizing these phosphors were found to undergo either a green shift or, less commonly, a red shift depending on the phosphor mix in themore » LED devices. These types of chromaticity shifts are classified as CSM-2 (green shift) and CSM-5 (red shift). This paper provides an overview of the kinetic processes responsible for green and red chromaticity shifts along with examples from accelerated stress testing of 6” downlights. Both CSMs appear to proceed through analogous mechanisms that are initiated at the surface of the phosphor. A green shift is produced by the surface oxidation of the nitride phosphor that changes the emission profile to lower wavelengths. As the surface oxidation reaction proceeds, reactant limitations slow the rate and bulk oxidation processes become more prevalent. We found that a red chromaticity shift arises from quenching of the green phosphor, also possibly due to surface reactions of oxygen, which shift the emission chromaticity in the red direction. In conclusion, we discuss the implications of these findings on projecting chromaticity.« less

  6. Effect of Chromate and Chromate-Free Organic Coatings on Corrosion Fatigue of an Aluminum Alloy

    DTIC Science & Technology

    2012-02-20

    Investigations of alloy AA7075 corrosion in acid rain solution, inhibited by chromate-free blends of zinc phosphate with bentonite, zeolite and calcium...with solution components. Single use of zinc phosphate and these ion exchanged pigments for corrosion inhibition do not provide desired effect...primer performance against corrosion fatigue cracking under a commercial polyurethane topcoat. As a control , they used samples of chromated AA2024

  7. Release of copper-amended particles from micronized copper-pressure-treated wood during mechanical abrasion.

    PubMed

    Civardi, Chiara; Schlagenhauf, Lukas; Kaiser, Jean-Pierre; Hirsch, Cordula; Mucchino, Claudio; Wichser, Adrian; Wick, Peter; Schwarze, Francis W M R

    2016-11-28

    We investigated the particles released due to abrasion of wood surfaces pressure-treated with micronized copper azole (MCA) wood preservative and we gathered preliminary data on its in vitro cytotoxicity for lung cells. The data were compared with particles released after abrasion of untreated, water (0% MCA)-pressure-treated, chromated copper (CC)-pressure-treated wood, and varnished wood. Size, morphology, and composition of the released particles were analyzed. Our results indicate that the abrasion of MCA-pressure-treated wood does not cause an additional release of nanoparticles from the unreacted copper (Cu) carbonate nanoparticles from of the MCA formulation. However, a small amount of released Cu was detected in the nanosized fraction of wood dust, which could penetrate the deep lungs. The acute cytotoxicity studies were performed on a human lung epithelial cell line and human macrophages derived from a monocytic cell line. These cell types are likely to encounter the released wood particles after inhalation. Our findings indicate that under the experimental conditions chosen, MCA does not pose a specific additional nano-risk, i.e. there is no additional release of nanoparticles and no specific nano-toxicity for lung epithelial cells and macrophages.

  8. Kinetics of chromate reduction during naphthalene degradation in a mixed culture

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shen, H.; Sewell, G.W.; Pritchard, P.H.

    A mixed culture of Bacillus sp. K1 and Sphingomonas paucimobilis EPA 505 was exposed to chromate and naphthalene. Batch experiments showed that chromate was reduced and naphthalene was degraded by the mixed culture. Chromate reduction occurred initially at a high rate followed by a decrease in rate until chromate reduction ceased. Chromate reduction decreased in the mixed culture when a lower ratio of S. paucimobilis EPA 505 to Bacillus sp. K1 was utilized. A kinetic model incorporating a term for the cell density ratio is proposed to describe chromate reduction in the mixed culture under both chromate limited and electronmore » donor limited conditions. The validity of the model, and its parameter values, was verified by experimental data generated under a variety of initial population compositions and a broad range of chromate concentrations. The consistent result of experimental data with model predictions implies that the model is useful for evaluating the interactions and the use of mixed culture for chromate removal.« less

  9. Stimulus size dependence of hue changes induced by chromatic surrounds.

    PubMed

    Kellner, Christian Johannes; Wachtler, Thomas

    2016-03-01

    A chromatic surround induces a change in the perceived hue of a stimulus. This shift in hue depends on the chromatic difference between the stimulus and the surround. We investigated how chromatic induction varies with stimulus size and whether the size dependence depends on the surround hue. Subjects performed asymmetric matching of color stimuli with different sizes in surrounds of different chromaticities. Generally, induced hue shifts decreased with increasing stimulus size. This decrease was quantitatively different for different surround hues. However, when size effects were normalized to an overall induction strength, the chromatic specificity was largely reduced. The separability of inducer chromaticity and stimulus size suggests that these effects are mediated by different neural mechanisms.

  10. [Analysis of chromatic value of gingival porcelain].

    PubMed

    Wang, Min; Sun, Jun; Chao, Yong-Lie

    2005-08-01

    To study the distribution of the chromatic value of gingival porcelains. The color change of Shofu VINTAGE and Vita VMK95 gingival porcelains on the black and white backings was determined with a spectrophotometer (PR-650). The results showed that the chromatic value of gingival porcelains was different on varying backings. The color space of gingival porcelain was L*: 41.85 - 50.64, a*: 12.46 - 19.46, b*: 1.33 - 4.62. The chromatic value distribution cannot cover the color region of natural gingiva.

  11. Redefining White Light Chromaticity Boundaries for Aviation

    DOT National Transportation Integrated Search

    2009-10-05

    Several aspects are involved in the recognition of an aviation signal light's color, including its chromaticity, layout on the airfield, and the chromaticity of other light sources in view. The LRC conducted a human factors investigation of the bound...

  12. Ocular Chromatic Aberrations and Their Effects on Polychromatic Retinal Image Quality

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoxiao

    Previous studies of ocular chromatic aberrations have concentrated on chromatic difference of focus (CDF). Less is known about the chromatic difference of image position (CDP) in the peripheral retina and no experimental attempt has been made to measure the ocular chromatic difference of magnification (CDM). Consequently, theoretical modelling of human eyes is incomplete. The insufficient knowledge of ocular chromatic aberrations is partially responsible for two unsolved applied vision problems: (1) how to improve vision by correcting ocular chromatic aberration? (2) what is the impact of ocular chromatic aberration on the use of isoluminance gratings as a tool in spatial-color vision?. Using optical ray tracing methods, MTF analysis methods of image quality, and psychophysical methods, I have developed a more complete model of ocular chromatic aberrations and their effects on vision. The ocular CDM was determined psychophysically by measuring the tilt in the apparent frontal parallel plane (AFPP) induced by interocular difference in image wavelength. This experimental result was then used to verify a theoretical relationship between the ocular CDM, the ocular CDF and the entrance pupil of the eye. In the retinal image after correcting the ocular CDF with existing achromatizing methods, two forms of chromatic aberration (CDM and chromatic parallax) were examined. The CDM was predicted by theoretical ray tracing and measured with the same method used to determine ocular CDM. The chromatic parallax was predicted with a nodal ray model and measured with the two-color vernier alignment method. The influence of these two aberrations on polychromatic MTF were calculated. Using this improved model of ocular chromatic aberration, luminance artifacts in the images of isoluminance gratings were calculated. The predicted luminance artifacts were then compared with experimental data from previous investigators. The results show that: (1) A simple relationship exists between

  13. Reduced chromatic discrimination in children with autism spectrum disorders.

    PubMed

    Franklin, Anna; Sowden, Paul; Notman, Leslie; Gonzalez-Dixon, Melissa; West, Dorotea; Alexander, Iona; Loveday, Stephen; White, Alex

    2010-01-01

    Atypical perception in Autism Spectrum Disorders (ASD) is well documented (Dakin & Frith, 2005). However, relatively little is known about colour perception in ASD. Less accurate performance on certain colour tasks has led some to argue that chromatic discrimination is reduced in ASD relative to typical development (Franklin, Sowden, Burley, Notman & Alder, 2008). The current investigation assessed chromatic discrimination in children with high-functioning autism (HFA) and typically developing (TD) children matched on age and non-verbal cognitive ability, using the Farnsworth-Munsell 100 hue test (Experiment 1) and a threshold discrimination task (Experiment 2). In Experiment 1, more errors on the chromatic discrimination task were made by the HFA than the TD group. Comparison with test norms revealed that performance for the HFA group was at a similar level to typically developing children around 3 years younger. In Experiment 2, chromatic thresholds were elevated for the HFA group relative to the TD group. For both experiments, reduced chromatic discrimination in ASD was due to a general reduction in chromatic sensitivity rather than a specific difficulty with either red-green or blue-yellow subsystems of colour vision. The absence of group differences on control tasks ruled out an explanation in terms of general task ability rather than chromatic sensitivity. Theories to account for the reduction in chromatic discrimination in HFA are discussed, and findings are related to cortical models of perceptual processing in ASD.

  14. Interactions between chromatic- and luminance-contrast-sensitive stereopsis mechanisms.

    PubMed

    Simmons, David R; Kingdom, Frederick A A

    2002-06-01

    It is well known that chromatic information can assist in solving the stereo correspondence problem. It has also been suggested that there are two independent first-order stereopsis mechanisms, one sensitive to chromatic contrast and the other sensitive to luminance contrast (Vision Research 37 (1997) 1271). Could the effect of chromatic information on stereo correspondence be subserved by interactions between these mechanisms? To address this question, disparity thresholds (1/stereoacuity) were measured using 0.5 cpd Gabor patches. The stimuli possessed different relative amounts of chromatic and luminance contrast which could be correlated or anti-correlated between the eyes. Stereoscopic performance with these compound stimuli was compared to that with purely isoluminant and isochromatic stimuli at different contrasts. It was found that anti-correlated chromatic contrast severely disrupted stereopsis with achromatic stimuli and that anti-correlated luminance contrast severely disrupted stereopsis with chromatic stimuli. Less dramatic, but still significant, was the improvement in stereoacuity obtained using correlated colour and luminance contrast. These data are consistent with there being positive and negative interactions between chromatic and achromatic stereopsis mechanisms that take place after the initial encoding of disparity information, but before the extraction of stereoscopic depth. These interactions can be modelled satisfactorily assuming probability summation of depth sign information between independent mechanisms.

  15. Chromatic assimilation unaffected by perceived depth of inducing light.

    PubMed

    Shevell, Steven K; Cao, Dingcai

    2004-01-01

    Chromatic assimilation is a shift toward the color of nearby light. Several studies conclude that a neural process contributes to assimilation but the neural locus remains in question. Some studies posit a peripheral process, such as retinal receptive-field organization, while others claim the neural mechanism follows depth perception, figure/ground segregation, or perceptual grouping. The experiments here tested whether assimilation depends on a neural process that follows stereoscopic depth perception. By introducing binocular disparity, the test field judged in color was made to appear in a different depth plane than the light that induced assimilation. The chromaticity and spatial frequency of the inducing light, and the chromaticity of the test light, were varied. Chromatic assimilation was found with all inducing-light sizes and chromaticities, but the magnitude of assimilation did not depend on the perceived relative depth planes of the test and inducing fields. We found no evidence to support the view that chromatic assimilation depends on a neural process that follows binocular combination of the two eyes' signals.

  16. Reward salience and risk aversion underlie differential ACC activity in substance dependence

    PubMed Central

    Alexander, William H.; Fukunaga, Rena; Finn, Peter; Brown, Joshua W.

    2015-01-01

    The medial prefrontal cortex, especially the dorsal anterior cingulate cortex (ACC), has long been implicated in cognitive control and error processing. Although the association between ACC and behavior has been established, it is less clear how ACC contributes to dysfunctional behavior such as substance dependence. Evidence from neuroimaging studies investigating ACC function in substance users is mixed, with some studies showing disengagement of ACC in substance dependent individuals (SDs), while others show increased ACC activity related to substance use. In this study, we investigate ACC function in SDs and healthy individuals performing a change signal task for monetary rewards. Using a priori predictions derived from a recent computational model of ACC, we find that ACC activity differs between SDs and controls in factors related to reward salience and risk aversion between SDs and healthy individuals. Quantitative fits of a computational model to fMRI data reveal significant differences in best fit parameters for reward salience and risk preferences. Specifically, the ACC in SDs shows greater risk aversion, defined as concavity in the utility function, and greater attention to rewards relative to reward omission. Furthermore, across participants risk aversion and reward salience are positively correlated. The results clarify the role that ACC plays in both the reduced sensitivity to omitted rewards and greater reward valuation in SDs. Clinical implications of applying computational modeling in psychiatry are also discussed. PMID:26106528

  17. Reward salience and risk aversion underlie differential ACC activity in substance dependence.

    PubMed

    Alexander, William H; Fukunaga, Rena; Finn, Peter; Brown, Joshua W

    2015-01-01

    The medial prefrontal cortex, especially the dorsal anterior cingulate cortex (ACC), has long been implicated in cognitive control and error processing. Although the association between ACC and behavior has been established, it is less clear how ACC contributes to dysfunctional behavior such as substance dependence. Evidence from neuroimaging studies investigating ACC function in substance users is mixed, with some studies showing disengagement of ACC in substance dependent individuals (SDs), while others show increased ACC activity related to substance use. In this study, we investigate ACC function in SDs and healthy individuals performing a change signal task for monetary rewards. Using a priori predictions derived from a recent computational model of ACC, we find that ACC activity differs between SDs and controls in factors related to reward salience and risk aversion between SDs and healthy individuals. Quantitative fits of a computational model to fMRI data reveal significant differences in best fit parameters for reward salience and risk preferences. Specifically, the ACC in SDs shows greater risk aversion, defined as concavity in the utility function, and greater attention to rewards relative to reward omission. Furthermore, across participants risk aversion and reward salience are positively correlated. The results clarify the role that ACC plays in both the reduced sensitivity to omitted rewards and greater reward valuation in SDs. Clinical implications of applying computational modeling in psychiatry are also discussed.

  18. Genetic profile of adenoid cystic carcinomas (ACC) with high-grade transformation versus solid type.

    PubMed

    Costa, Ana Flávia; Altemani, Albina; Vékony, Hedy; Bloemena, Elisabeth; Fresno, Florentino; Suárez, Carlos; Llorente, José Luis; Hermsen, Mario

    2010-01-01

    ACC can occasionally undergo dedifferentiation also referred to as high-grade transformation (ACC-HGT). However, ACC-HGT can also undergo transformation to adenocarcinomas which are not poorly differentiated. ACC-HGT is generally considered to be an aggressive variant of ACC, even more than solid ACC. This study was aimed to describe the genetic changes of ACC-HGT in relation to clinico-pathological features and to compare results to solid ACC. genome-wide DNA copy number changes were analyzed by microarray CGH in ACC-HGT, 4 with transformation into moderately differentiated adenocarcinoma (MDA) and two into poorly differentiated carcinoma (PDC), 5 solid ACC. In addition, Ki-67 index and p53 immunopositivity was assessed. ACC-HGT carried fewer copy number changes compared to solid ACC. Two ACC-HGT cases harboured a breakpoint at 6q23, near the cMYB oncogene. The complexity of the genomic profile concurred with the clinical course of the patient. Among the ACC-HGT, p53 positivity significantly increased from the conventional to the transformed (both MDA and PDC) component. ACC-HGT may not necessarily reflect a more advanced stage of tumor progression, but rather a transformation to another histological form in which the poorly differentiated forms (PDC) presents a genetic complexity similar to the solid ACC.

  19. Genetic profile of adenoid cystic carcinomas (ACC) with high-grade transformation versus solid type.

    PubMed

    Costa, Ana Flávia; Altemani, Albina; Vékony, Hedy; Bloemena, Elisabeth; Fresno, Florentino; Suárez, Carlos; Llorente, José Luis; Hermsen, Mario

    2011-08-01

    ACC can occasionally undergo dedifferentiation also referred to as high-grade transformation (ACC-HGT). However, ACC-HGT can also undergo transformation to adenocarcinomas which are not poorly differentiated. ACC-HGT is generally considered to be an aggressive variant of ACC, even more than solid ACC. This study was aimed to describe the genetic changes of ACC-HGT in relation to clinico-pathological features, and to compare results to solid ACC. Genome wide DNA copy number changes were analyzed by microarray CGH in ACC-HGT, four with transformation into moderately differentiated adenocarcinoma (MDA) and two into poorly differentiated carcinoma (PDC), and five solid ACC. In addition, Ki67 index and p53 immunopositivity was assessed. ACC-HGT carried fewer copy number changes compared to solid ACC. Two ACC-HGT cases harboured a breakpoint at 6q23, near the cMYB oncogene. The complexity of the genomic profile concurred with the clinical course of the patient. Among the ACC-HGT, p53 positivity significantly increased from the conventional to the transformed (both MDA and PDC) component. ACC-HGT may not necessarily reflect a more advanced stage of tumor progression, but rather a transformation to another histological form in which the poorly differentiated forms (PDC) presents a genetic complexity similar to the solid ACC.

  20. Genotype-specific enrichment of ACC deaminase-positive bacteria in winter wheat rhizospheres

    USDA-ARS?s Scientific Manuscript database

    Bacteria that produce ACC deaminase promote plant growth and development by lowering levels of the stress hormone ethylene through deamination of 1-aminocyclopropane-1-carboxylic acid (ACC), the immediate precursor of ethylene. Therefore, it is hypothesized that ACC deaminase positive (ACC+) bacteri...

  1. Assessing the release of copper from nanocopper-treated and conventional copper-treated lumber into marine waters I: Concentrations and rates.

    PubMed

    Parks, Ashley N; Cantwell, Mark G; Katz, David R; Cashman, Michaela A; Luxton, Todd P; Ho, Kay T; Burgess, Robert M

    2018-03-25

    Little is known about the release of metal engineered nanomaterials (ENMs) from consumer goods, including lumber treated with micronized copper. Micronized copper is a recent form of antifouling wood preservative containing nanosized copper particles for use in pressure-treated lumber. The present study investigated the concentrations released and the release rate of total copper over the course of 133 d under freshwater, estuarine, and marine salinity conditions (0, 1, 10, and 30‰) for several commercially available pressure-treated lumbers: micronized copper azole (MCA) at 0.96 and 2.4 kg/m 3 , alkaline copper quaternary (ACQ) at 0.30 and 9.6 kg/m 3 , and chromated copper arsenate (CCA) at 40 kg/m 3 . Lumber was tested as blocks and as sawdust. Overall, copper was released from all treated lumber samples. Under leaching conditions, total release ranged from 2 to 55% of the measured copper originally in the lumber, with release rate constants from the blocks of 0.03 to 2.71 (units per day). Generally, measured release and modeled equilibrium concentrations were significantly higher in the estuarine conditions compared with freshwater or marine salinities, whereas rate constants showed very limited differences between salinities. Furthermore, organic carbon was released during the leaching and demonstrated a significant relationship with released copper concentrations as a function of salinity. The results indicate that copper is released into estuarine/marine waters from multiple wood treatments including lumber amended with nanoparticle-sized copper. Environ Toxicol Chem 2018;9999:1-13. Published 2018 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2018 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

  2. Long-term soil accumulation of chromium, copper, and arsenic adjacent to preservative-treated wood.

    Treesearch

    S. Lebow; D. Foster; J. Evans

    2004-01-01

    Chromated copper arsenate (CCA) treated wood has been used extensively in outdoor applications. The Environmental Protection Agency (EPA) and CCA producers recently reached an agreement to limit future use of CCA for some types of applications. One area of concern is the long-term accumulation of leached CCA in soil adjacent to treated wood structures. Interpreting...

  3. Changes in unique hues induced by chromatic surrounds.

    PubMed

    Klauke, Susanne; Wachtler, Thomas

    2016-03-01

    A chromatic surround can have a strong influence on the perceived hue of a stimulus. We investigated whether chromatic induction has similar effects on the perception of colors that appear pure and unmixed (unique red, green, blue, and yellow) as on other colors. Subjects performed unique hue settings of stimuli in isoluminant surrounds of different chromaticities. Compared with the settings in a neutral gray surround, unique hue settings altered systematically with chromatic surrounds. The amount of induced hue shift depended on the difference between stimulus and surround hues, and was similar for unique hue settings as for settings of nonunique hues. Intraindividual variability in unique hue settings was roughly twice as high as for settings obtained in asymmetric matching experiments, which may reflect the presence of a reference stimulus in the matching task. Variabilities were also larger with chromatic surrounds than with neutral gray surrounds, for both unique hue settings and matching of nonunique hues. The results suggest that the neural representations underlying unique hue percepts are influenced by the same neural processing mechanisms as the percepts of other colors.

  4. Chromate dermatitis from a boiler lining.

    PubMed

    Rycroft, R J; Calnan, C D

    1977-08-01

    Chromate dermatitis is described in a mechanical fitter working inside boiler combustion chambers. A source of hexavalent chromate is traced to the action of the heat and alkaline fuel ash on trivalent chrome ore in parts of the refractory lining. Removal of the patient from this contact has resulted in almost complete clearing of his dermatitis, without any relapse, during a 9-month follow-up period.

  5. Influence of Spatial and Chromatic Noise on Luminance Discrimination.

    PubMed

    Miquilini, Leticia; Walker, Natalie A; Odigie, Erika A; Guimarães, Diego Leite; Salomão, Railson Cruz; Lacerda, Eliza Maria Costa Brito; Cortes, Maria Izabel Tentes; de Lima Silveira, Luiz Carlos; Fitzgerald, Malinda E C; Ventura, Dora Fix; Souza, Givago Silva

    2017-12-05

    Pseudoisochromatic figures are designed to base discrimination of a chromatic target from a background solely on the chromatic differences. This is accomplished by the introduction of luminance and spatial noise thereby eliminating these two dimensions as cues. The inverse rationale could also be applied to luminance discrimination, if spatial and chromatic noise are used to mask those cues. In this current study estimate of luminance contrast thresholds were conducted using a novel stimulus, based on the use of chromatic and spatial noise to mask the use of these cues in a luminance discrimination task. This was accomplished by presenting stimuli composed of a mosaic of circles colored randomly. A Landolt-C target differed from the background only by the luminance. The luminance contrast thresholds were estimated for different chromatic noise saturation conditions and compared to luminance contrast thresholds estimated using the same target in a non-mosaic stimulus. Moreover, the influence of the chromatic content in the noise on the luminance contrast threshold was also investigated. Luminance contrast threshold was dependent on the chromaticity noise strength. It was 10-fold higher than thresholds estimated from non-mosaic stimulus, but they were independent of colour space location in which the noise was modulated. The present study introduces a new method to investigate luminance vision intended for both basic science and clinical applications.

  6. Genetic Profile of Adenoid Cystic Carcinomas (ACC) with High-Grade Transformation versus Solid Type

    PubMed Central

    Costa, Ana Flávia; Altemani, Albina; Vékony, Hedy; Bloemena, Elisabeth; Fresno, Florentino; Suárez, Carlos; Llorente, José Luis; Hermsen, Mario

    2010-01-01

    Background: ACC can occasionally undergo dedifferentiation also referred to as high-grade transformation (ACC-HGT). However, ACC-HGT can also undergo transformation to adenocarcinomas which are not poorly differentiated. ACC-HGT is generally considered to be an aggressive variant of ACC, even more than solid ACC. This study was aimed to describe the genetic changes of ACC-HGT in relation to clinico-pathological features and to compare results to solid ACC. Methods: Genome-wide DNA copy number changes were analyzed by microarray CGH in ACC-HGT, 4 with transformation into moderately differentiated adenocarcinoma (MDA) and two into poorly differentiated carcinoma (PDC), 5 solid ACC. In addition, Ki-67 index and p53 immunopositivity was assessed. Results: ACC-HGT carried fewer copy number changes compared to solid ACC. Two ACC-HGT cases harboured a breakpoint at 6q23, near the cMYB oncogene. The complexity of the genomic profile concurred with the clinical course of the patient. Among the ACC-HGT, p53 positivity significantly increased from the conventional to the transformed (both MDA and PDC) component. Conclusion: ACC-HGT may not necessarily reflect a more advanced stage of tumor progression, but rather a transformation to another histological form in which the poorly differentiated forms (PDC) presents a genetic complexity similar to the solid ACC. PMID:20978318

  7. chroma: Chromatic effects for LSST weak lensing

    NASA Astrophysics Data System (ADS)

    Meyers, Joshua E.; Burchat, Patricia R.

    2018-04-01

    Chroma investigates biases originating from two chromatic effects in the atmosphere: differential chromatic refraction (DCR), and wavelength dependence of seeing. These biases arise when using the point spread function (PSF) measured with stars to estimate the shapes of galaxies with different spectral energy distributions (SEDs) than the stars.

  8. Chromatic diversity: a new approach for characterizing spatiotemporal coupling of ultrashort pulses.

    PubMed

    Bahk, Seung-Whan; Dorrer, Christophe; Bromage, Jake

    2018-04-02

    Two-dimensional chromatic aberrations are characterized by a single-shot scheme based on a simultaneous measurement of chromatically diversified focal spots. The chromatic diversity is introduced by a 2-D grating with holographic defocus terms. The chromatic aberrations in the beam are either subtracted or added by the additional known chromatic aberrations in the grating, depending on the diffraction order. By analyzing the asymmetry in the size of diffracted focal spots, input beam chromatic aberrations can be deduced. Theoretical discussions and experimental results are presented.

  9. Chromatic diversity: a new approach for characterizing spatiotemporal coupling of ultrashort pulses

    DOE PAGES

    Bahk, Seung-Whan; Dorrer, Christophe; Bromage, Jake

    2018-01-01

    Two-dimensional chromatic aberrations are characterized by a single-shot scheme based on a simultaneous measurement of chromatically diversified focal spots. The chromatic diversity is introduced by a 2-D grating with holographic defocus terms. The chromatic aberrations in the beam are either subtracted or added by the additional known chromatic aberrations in the grating, depending on the diffraction order. By analyzing the asymmetry in the size of diffracted focal spots, input beam chromatic aberrations can be deduced. Theoretical discussions and experimental results are also presented.

  10. The effect of chromatic and luminance information on reaction times.

    PubMed

    O'Donell, Beatriz M; Barraza, Jose F; Colombo, Elisa M

    2010-07-01

    We present a series of experiments exploring the effect of chromaticity on reaction time (RT) for a variety of stimulus conditions, including chromatic and luminance contrast, luminance, and size. The chromaticity of these stimuli was varied along a series of vectors in color space that included the two chromatic-opponent-cone axes, a red-green (L-M) axis and a blue-yellow [S - (L + M)] axis, and intermediate noncardinal orientations, as well as the luminance axis (L + M). For Weber luminance contrasts above 10-20%, RTs tend to the same asymptote, irrespective of chromatic direction. At lower luminance contrast, the addition of chromatic information shortens the RT. RTs are strongly influenced by stimulus size when the chromatic stimulus is modulated along the [S - (L + M)] pathway and by stimulus size and adaptation luminance for the (L-M) pathway. RTs are independent of stimulus size for stimuli larger than 0.5 deg. Data are modeled with a modified version of Pieron's formula with an exponent close to 2, in which the stimulus intensity term is replaced by a factor that considers the relative effects of chromatic and achromatic information, as indexed by the RMS (square-root of the cone contrast) value at isoluminance and the Weber luminance contrast, respectively. The parameters of the model reveal how RT is linked to stimulus size, chromatic channels, and adaptation luminance and how they can be interpreted in terms of two chromatic mechanisms. This equation predicts that, for isoluminance, RTs for a stimulus lying on the S-cone pathway are higher than those for a stimulus lying on the L-M-cone pathway, for a given RMS cone contrast. The equation also predicts an asymptotic trend to the RT for an achromatic stimulus when the luminance contrast is sufficiently large.

  11. Effect of prestain on the release rate of copper, chromium, and arsenic from western hemlock

    Treesearch

    Stan T. Lebow; James W. Evans

    1999-01-01

    To enhance appearance, stains are often sprayed onto western hemlock (Tsuga heterophylla (Raf.) Sarg.) lumber prior to treatment with chromated copper arsenate (CCA-C). Recently, concerns have increased that prestaining may affect the rate of leaching of CCA-C components from the treated wood and that leaching data generated with prestained material may not reflect...

  12. Method For Creating Corrosion Resistant Surface On An Aluminum Copper Alloy

    DOEpatents

    Mansfeld, Florian B.; Wang, You; Lin, Simon H.

    1997-06-03

    A method for treating the surface of aluminum alloys hang a relatively high copper content is provided which includes the steps of removing substantially all of the copper from the surface, contacting the surface with a first solution containing cerium, electrically charging the surface while contacting the surface in an aqueous molybdate solution, and contacting the surface with a second solution containing cerium. The copper is substantially removed from the surface in the first step either by (i) contacting the surface with an acidic chromate solution or by (ii) contacting the surface with an acidic nitrate solution while subjecting the surface to an electric potential. The corrosion-resistant surface resulting from the invention is excellent, consistent and uniform throughout the surface. Surfaces treated by the invention may often be certified for use in salt-water services.

  13. Symplectic maps and chromatic optics in particle accelerators

    DOE PAGES

    Cai, Yunhai

    2015-07-06

    Here, we have applied the nonlinear map method to comprehensively characterize the chromatic optics in particle accelerators. Our approach is built on the foundation of symplectic transfer maps of magnetic elements. The chromatic lattice parameters can be transported from one element to another by the maps. We also introduce a Jacobian operator that provides an intrinsic linkage between the maps and the matrix with parameter dependence. The link allows us to directly apply the formulation of the linear optics to compute the chromatic lattice parameters. As an illustration, we analyze an alternating-gradient cell with nonlinear sextupoles, octupoles, and decapoles andmore » derive analytically their settings for the local chromatic compensation. Finally, the cell becomes nearly perfect up to the third-order of the momentum deviation.« less

  14. Asian Care Certificate (ACC): a care quality assurance framework.

    PubMed

    Talaie, Tony

    2018-04-16

    Purpose Quality assuring elderly care through a viable and feasible standard framework is a major challenge for Asian governments. Although several attempts have been made to tackle foreign care worker (FCW) shortage, assuring the quality of the care they provide has been overlooked. The original framework allowed a better control over service quality to assure the elderly about their care according to the agreed standards. The paper aims to discuss these issues. Design/methodology/approach Through several Japanese Governmental meetings, a new Asian Care Certificate (ACC) program is discussed based on the Japanese Care Certificate (JCC). The governments' representatives adopted the JCC to form the ACC, which enables the ACC board to evaluate care workers and to intervene whenever the desired quality level is not achieved. Findings The author describes a new program. The findings of this paper will be confirmed when the ACC is implemented. Practical implications Using the ACC framework, the challenge in providing a high-quality care service using FCWs across Asia would be partly resolved. FCWs' quality of life might also gradually improve especially regarding to their human rights. Originality/value The ACC provides a new framework. Its value is recognized if one considers that many Asian populations are rapidly aging and many governments compromise quality by employing overseas workers to solve care worker shortages.

  15. Simultaneous chromatic and luminance human electroretinogram responses.

    PubMed

    Parry, Neil R A; Murray, Ian J; Panorgias, Athanasios; McKeefry, Declan J; Lee, Barry B; Kremers, Jan

    2012-07-01

    The parallel processing of information forms an important organisational principle of the primate visual system. Here we describe experiments which use a novel chromatic–achromatic temporal compound stimulus to simultaneously identify colour and luminance specific signals in the human electroretinogram (ERG). Luminance and chromatic components are separated in the stimulus; the luminance modulation has twice the temporal frequency of the chromatic modulation. ERGs were recorded from four trichromatic and two dichromatic subjects (1 deuteranope and 1 protanope). At isoluminance, the fundamental (first harmonic) response was elicited by the chromatic component in the stimulus. The trichromatic ERGs possessed low-pass temporal tuning characteristics, reflecting the activity of parvocellular post-receptoral mechanisms. There was very little first harmonic response in the dichromats' ERGs. The second harmonic response was elicited by the luminance modulation in the compound stimulus and showed, in all subjects, band-pass temporal tuning characteristic of magnocellular activity. Thus it is possible to concurrently elicit ERG responses from the human retina which reflect processing in both chromatic and luminance pathways. As well as providing a clear demonstration of the parallel nature of chromatic and luminance processing in the human retina, the differences that exist between ERGs from trichromatic and dichromatic subjects point to the existence of interactions between afferent post-receptoral pathways that are in operation from the earliest stages of visual processing.

  16. Simultaneous chromatic and luminance human electroretinogram responses

    PubMed Central

    Parry, Neil R A; Murray, Ian J; Panorgias, Athanasios; McKeefry, Declan J; Lee, Barry B; Kremers, Jan

    2012-01-01

    The parallel processing of information forms an important organisational principle of the primate visual system. Here we describe experiments which use a novel chromatic–achromatic temporal compound stimulus to simultaneously identify colour and luminance specific signals in the human electroretinogram (ERG). Luminance and chromatic components are separated in the stimulus; the luminance modulation has twice the temporal frequency of the chromatic modulation. ERGs were recorded from four trichromatic and two dichromatic subjects (1 deuteranope and 1 protanope). At isoluminance, the fundamental (first harmonic) response was elicited by the chromatic component in the stimulus. The trichromatic ERGs possessed low-pass temporal tuning characteristics, reflecting the activity of parvocellular post-receptoral mechanisms. There was very little first harmonic response in the dichromats’ ERGs. The second harmonic response was elicited by the luminance modulation in the compound stimulus and showed, in all subjects, band-pass temporal tuning characteristic of magnocellular activity. Thus it is possible to concurrently elicit ERG responses from the human retina which reflect processing in both chromatic and luminance pathways. As well as providing a clear demonstration of the parallel nature of chromatic and luminance processing in the human retina, the differences that exist between ERGs from trichromatic and dichromatic subjects point to the existence of interactions between afferent post-receptoral pathways that are in operation from the earliest stages of visual processing. PMID:22586211

  17. 24 CFR 985.109 - Default under the Annual Contributions Contract (ACC).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Contributions Contract (ACC). 985.109 Section 985.109 Housing and Urban Development REGULATIONS RELATING TO... § 985.109 Default under the Annual Contributions Contract (ACC). HUD may determine that an PHA's failure... required by HUD constitutes a default under the ACC. ...

  18. 24 CFR 985.109 - Default under the Annual Contributions Contract (ACC).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Contributions Contract (ACC). 985.109 Section 985.109 Housing and Urban Development Regulations Relating to... § 985.109 Default under the Annual Contributions Contract (ACC). HUD may determine that an PHA's failure... required by HUD constitutes a default under the ACC. ...

  19. Detection of chromatic and luminance distortions in natural scenes.

    PubMed

    Jennings, Ben J; Wang, Karen; Menzies, Samantha; Kingdom, Frederick A A

    2015-09-01

    A number of studies have measured visual thresholds for detecting spatial distortions applied to images of natural scenes. In one study, Bex [J. Vis.10(2), 1 (2010)10.1167/10.2.231534-7362] measured sensitivity to sinusoidal spatial modulations of image scale. Here, we measure sensitivity to sinusoidal scale distortions applied to the chromatic, luminance, or both layers of natural scene images. We first established that sensitivity does not depend on whether the undistorted comparison image was of the same or of a different scene. Next, we found that, when the luminance but not chromatic layer was distorted, performance was the same regardless of whether the chromatic layer was present, absent, or phase-scrambled; in other words, the chromatic layer, in whatever form, did not affect sensitivity to the luminance layer distortion. However, when the chromatic layer was distorted, sensitivity was higher when the luminance layer was intact compared to when absent or phase-scrambled. These detection threshold results complement the appearance of periodic distortions of the image scale: when the luminance layer is distorted visibly, the scene appears distorted, but when the chromatic layer is distorted visibly, there is little apparent scene distortion. We conclude that (a) observers have a built-in sense of how a normal image of a natural scene should appear, and (b) the detection of distortion in, as well as the apparent distortion of, natural scene images is mediated predominantly by the luminance layer and not chromatic layer.

  20. In vivo longitudinal chromatic aberration of pseudophakic eyes.

    PubMed

    Siedlecki, Damian; Jóźwik, Agnieszka; Zając, Marek; Hill-Bator, Aneta; Turno-Kręcicka, Anna

    2014-02-01

    To present the results of longitudinal chromatic aberration measurements on two groups of pseudophakic eyes in comparison to healthy eyes. The longitudinal chromatic aberration of the eye, defined as chromatic difference of refraction with disabled accommodation, was measured with the use of a visual refractometer with a custom-designed target illuminator consisting of a narrow-band RGB diode (blue λb = 470 ± 15 nm; green λg = 525 ± 18 nm; red λr = 660 ± 10 nm). The measurements were performed on nine eyes implanted with AcrySof IQ SN60WF, 14 eyes implanted with AcrySof SA60AT, and 10 phakic eyes under cycloplegia. The mean values of the longitudinal chromatic aberration between 470 and 660 nm for the control group was 1.12 ± 0.14 D. For SA60AT group, it was 1.45 ± 0.42 D whereas for SN60WF it was 1.17 ± 0.52 D. The statistical test showed significant difference between SA60AT and the control group (p < 0.05) and no significant difference between SN60WF and the control groups (p = 0.64). The study showed that the longitudinal chromatic aberration in vivo can be easily and reliably estimated with an adapted visual refractometer. The two groups of pseudophakic eyes measured in this study showed different values of chromatic aberration. Its magnitude for SA60AT group was significantly larger than for the control group whereas for SN60WF the difference was not significant. The optical material used for intraocular lens design may have significant influence on the magnitude of the chromatic aberration of the pseudophakic eye, and therefore on its optical and visual performance in polychromatic light.

  1. Luminance cues constrain chromatic blur discrimination in natural scene stimuli.

    PubMed

    Sharman, Rebecca J; McGraw, Paul V; Peirce, Jonathan W

    2013-03-22

    Introducing blur into the color components of a natural scene has very little effect on its percept, whereas blur introduced into the luminance component is very noticeable. Here we quantify the dominance of luminance information in blur detection and examine a number of potential causes. We show that the interaction between chromatic and luminance information is not explained by reduced acuity or spatial resolution limitations for chromatic cues, the effective contrast of the luminance cue, or chromatic and achromatic statistical regularities in the images. Regardless of the quality of chromatic information, the visual system gives primacy to luminance signals when determining edge location. In natural viewing, luminance information appears to be specialized for detecting object boundaries while chromatic information may be used to determine surface properties.

  2. FIELD-SCALE LEACHING OF ARSENIC, CHROMIUM AND COPPER FROM WEATHERED TREATED WOOD

    PubMed Central

    Hasan, A. Rasem; Hu, Ligang; Solo-Gabriele, Helena M.; Fieber, Lynne; Cai, Yong; Townsend, Timothy G.

    2010-01-01

    Earlier studies documented the loss of wood preservatives from new wood. The objective of this study was to evaluate losses from weathered treated wood under field conditions by collecting rainfall leachate from 5 different wood types, all with a surface area of 0.21 m2. Wood samples included weathered chromate copper arsenate (CCA) treated wood at low (2.7 kg/m3), medium (4.8 kg/m3) and high (35.4 kg/m3) retention levels, new alkaline copper quat (ACQ) treated wood (1.1 kg/m3 as CuO) and new untreated wood. Arsenic was found to leach at a higher rate (100 mg in 1 year for low retention) than chromium and copper (<40 mg) in all CCA treated wood samples. Copper leached at the highest rate from the ACQ sample (670 mg). Overall results suggest that metals’ leaching is a continuous process driven by rainfall, and that the mechanism of release from the wood matrix changes as wood weathers. PMID:20053493

  3. 24 CFR 969.105 - Extension of ACC upon payment of operating subsidy.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Extension of ACC upon payment of... COMPLETION OF DEBT SERVICE § 969.105 Extension of ACC upon payment of operating subsidy. (a) ACC amendment... projects under a particular ACC for a PHA fiscal year beginning after the effective date of this part, the...

  4. 24 CFR 969.105 - Extension of ACC upon payment of operating subsidy.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Extension of ACC upon payment of... COMPLETION OF DEBT SERVICE § 969.105 Extension of ACC upon payment of operating subsidy. (a) ACC amendment... projects under a particular ACC for a PHA fiscal year beginning after the effective date of this part, the...

  5. The influence of chromatic context on binocular color rivalry: Perception and neural representation

    PubMed Central

    Hong, Sang Wook; Shevell, Steven K.

    2008-01-01

    The predominance of rivalrous targets is affected by surrounding context when stimuli rival in orientation, motion or color. This study investigated the influence of chromatic context on binocular color rivalry. The predominance of rivalrous chromatic targets was measured in various surrounding contexts. The first experiment showed that a chromatic surround's influence was stronger when the surround was uniform or a grating with luminance contrast (chromatic/black grating) compared to an equiluminant grating (chromatic/white). The second experiment revealed virtually no effect of the orientation of the surrounding chromatic context, using chromatically rivalrous vertical gratings. These results are consistent with a chromatic representation of the context by a non-oriented, chromatically selective and spatially antagonistic receptive field. Neither a double-opponent receptive field nor a receptive field without spatial antagonism accounts for the influence of context on binocular color rivalry. PMID:18331750

  6. 24 CFR 882.403 - ACC, housing assistance payments contract, and lease.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false ACC, housing assistance payments... Procedures for Moderate Rehabilitation-Basic Policies § 882.403 ACC, housing assistance payments contract, and lease. (a) Maximum Total ACC Commitments. The maximum total annual contribution that may be...

  7. Replacement of chromates in paints and corrosion protection systems [Stage 1

    DOT National Transportation Integrated Search

    2004-05-01

    This technical report presents the first stage results of a multi-year project to develop chromate-free paints and corrosion protection systems. Chromate coatings and chromate-containing paints are very effective in providing corrosion resistance and...

  8. Effects of chromatic image statistics on illumination induced color differences.

    PubMed

    Lucassen, Marcel P; Gevers, Theo; Gijsenij, Arjan; Dekker, Niels

    2013-09-01

    We measure the color fidelity of visual scenes that are rendered under different (simulated) illuminants and shown on a calibrated LCD display. Observers make triad illuminant comparisons involving the renderings from two chromatic test illuminants and one achromatic reference illuminant shown simultaneously. Four chromatic test illuminants are used: two along the daylight locus (yellow and blue), and two perpendicular to it (red and green). The observers select the rendering having the best color fidelity, thereby indirectly judging which of the two test illuminants induces the smallest color differences compared to the reference. Both multicolor test scenes and natural scenes are studied. The multicolor scenes are synthesized and represent ellipsoidal distributions in CIELAB chromaticity space having the same mean chromaticity but different chromatic orientations. We show that, for those distributions, color fidelity is best when the vector of the illuminant change (pointing from neutral to chromatic) is parallel to the major axis of the scene's chromatic distribution. For our selection of natural scenes, which generally have much broader chromatic distributions, we measure a higher color fidelity for the yellow and blue illuminants than for red and green. Scrambled versions of the natural images are also studied to exclude possible semantic effects. We quantitatively predict the average observer response (i.e., the illuminant probability) with four types of models, differing in the extent to which they incorporate information processing by the visual system. Results show different levels of performance for the models, and different levels for the multicolor scenes and the natural scenes. Overall, models based on the scene averaged color difference have the best performance. We discuss how color constancy algorithms may be improved by exploiting knowledge of the chromatic distribution of the visual scene.

  9. Binocular interactions in random chromatic changes at isoluminance

    NASA Astrophysics Data System (ADS)

    Medina, José M.

    2006-02-01

    To examine the type of chromatic interactions at isoluminance in the phenomenon of binocular vision, I have determined simple visual reaction times (VRT) under three observational conditions (monocular left, monocular right, and binocular) for different chromatic stimuli along random color axes at isoluminance (simultaneous L-, M-, and S-cone variations). Upper and lower boundaries of probability summation as well as the binocular capacity coefficient were estimated with observed distributions of reaction times. The results were not consistent with the notion of independent chromatic channels between eyes, suggesting the existence of excitatory and inhibitory binocular interactions at suprathreshold isoluminance conditions.

  10. A linear chromatic mechanism drives the pupillary response.

    PubMed Central

    Tsujimura, S.; Wolffsohn, J. S.; Gilmartin, B.

    2001-01-01

    Previous studies have shown that a chromatic mechanism can drive pupil responses. The aim of this research was to clarify whether a linear or nonlinear chromatic mechanism drives pupillary responses by using test stimuli of various colours that are defined in cone contrast space. The pupil and accommodation responses evoked by these test stimuli were continuously and simultaneously objectively measured by photorefraction. The results with isochromatic and isoluminant stimuli showed that the accommodative level remained approximately constant (< 0.25 D change in mean level) even when the concurrent pupillary response was large (ca. 0.30 mm). The pupillary response to an isoluminant grating was sustained, delayed (by ca. 60 ms) and larger in amplitude than that for a isochromatic uniform stimulus, which supports previous work suggesting that the chromatic mechanism contributes to the pupillary response. In a second experiment, selected chromatic test gratings were used and isoresponse contours in cone contrast space were obtained. The results showed that the isoresponse contour in cone contrast space is well described (r(2) = 0.99) by a straight line with a positive slope. The results indicate that a /L - M/ linear chromatic mechanism, whereby a signal from the long wavelength cone is subtracted from that of the middle wavelength cone and vice versa, drives pupillary responses. PMID:11674867

  11. Copper in the intake and discharge zones of the Surry and Salem Nuclear Power Stations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Harrison, F.L.; Bishop, D.J.; Rice, D.W. Jr.

    Copper concentrations were measured in the soluble and particulate fractions of water samples and bedload sediments collected in intake and discharge areas of the Surry and Salem Nuclear Power Stations during normal operations. Additional samples of water and suspended particles were collected during startup of Unit 2 at the Salem Power Station. In water samples collected from Surry, total copper ranged from 6.5 to 24.7 and labile copper from 0.5 to 2.9 ..mu..g/L; in those from Salem, total copper ranged from 6.7 to 10.6 and labile from 0.9 to 3.8 ..mu..g/L. At both sites the highest total copper concentration wasmore » measured in January 1979 during a period of high runoff. In general, differences between influent and effluent waters were small; the maximum was 4.2 ..mu..g Cu/L. Copper concentration in the water during startup of Unit 2 of Salem was high initially (>2500 ..mu..g Cu/L) but was almost entirely in the particulate fraction; labile copper was only 0.6 ..mu..g/L. The apparent complexing capacity (ACC) of the waters from Surry ranged from 6 to 40 and those from Salem from 5 to 60 ..mu..g Cu/L. Ranges in dissolved organic carbon were smaller, 2.9 to 5.1 and 2.2 to 5.0 mg C/L for Surry and Salem, respectively, and showed no relationship with ACC. Ultrafiltration of discharge waters indicated that, in most samples, the largest fraction of copper in the untreated water was in the >10,000 <100,000 molecular weight fraction; in waters treated to destroy dissolved organic carbon, it was generally in the >100,000 molecular weight fraction.Copper concentrations in intact bedload sediments from the intake area of Surry ranged from 2.3 to 26 and of Salem from 36 to 74 ..mu..g/g dry weight; those in the discharge area of Surry ranged from 13 to 30 and of Salem from 3 to 67. We noted considerable spatial heterogeneity both at the intake and discharge areas, and higher copper concentrations in the <62-..mu..m fraction than in intact sediments.« less

  12. A genetic screen reveals a periplasmic copper chaperone required for nitrite reductase activity in pathogenic Neisseria.

    PubMed

    Jen, Freda E-C; Djoko, Karrera Y; Bent, Stephen J; Day, Christopher J; McEwan, Alastair G; Jennings, Michael P

    2015-09-01

    Under conditions of low oxygen availability, Neisseria meningitidis and Neisseria gonorrhoeae are able to respire via a partial denitrification pathway in which nitrite is converted to nitrous oxide. In this process, nitrite reductase (AniA), a copper (Cu)-containing protein converts nitrite to NO, and this product is converted to nitrous oxide by nitric oxide reductase (NorB). NorB also confers protection against toxic NO, and so we devised a conditional lethal screen, using a norB mutant, to identify mutants that were resistant to nitrite-dependent killing. After random-deletion mutagenesis of N. meningitidis, this genetic screen identified a gene encoding a Cu chaperone that is essential for AniA function, AccA. Purified AccA binds one Cu (I) ion and also possesses a second binding site for Cu (II). This novel periplasmic Cu chaperone (AccA) appears to be essential for provision of Cu ions to AniA of pathogenic Neisseria to generate an active nitrite reductase. Apart from the Neisseria genus, AccA is distributed across a wide range of environmental Proteobacteria species. © FASEB.

  13. Chromatic Dimensions Earthy, Watery, Airy, and Fiery.

    PubMed

    Albertazzi, Liliana; Koenderink, Jan J; van Doorn, Andrea

    2015-01-01

    In our study, for a small number of antonyms, we investigate whether they are cross-modally or ideaesthetically related to the space of colors. We analyze the affinities of seven antonyms (cold-hot, dull-radiant, dead-vivid, soft-hard, transparent-chalky, dry-wet, and acid-treacly) and their intermediate connotations (cool-warm, matt-shiny, numb-lively, mellow-firm, semi-transparent-opaque, semi-dry-moist, and sour-sweet) as a function of color. We find that some antonyms relate to chromatic dimensions, others to achromatic ones. The cold-hot antonym proves to be the most salient dimension. The dry-wet dimension coincides with the cold-hot dimension, with dry corresponding to hot and wet to cold. The acid-treacly dimension proves to be transversal to the cold-hot dimension; hence, the pairs mutually span the chromatic domain. The cold-hot and acid-treacly antonyms perhaps recall Hering's opponent color system. The dull-radiant, transparent-chalky, and dead-vivid pairs depend little upon chromaticity. Of all seven antonyms, only the soft-hard one turns out to be independent of the chromatic structure. © The Author(s) 2015.

  14. Portable LQCD Monte Carlo code using OpenACC

    NASA Astrophysics Data System (ADS)

    Bonati, Claudio; Calore, Enrico; Coscetti, Simone; D'Elia, Massimo; Mesiti, Michele; Negro, Francesco; Fabio Schifano, Sebastiano; Silvi, Giorgio; Tripiccione, Raffaele

    2018-03-01

    Varying from multi-core CPU processors to many-core GPUs, the present scenario of HPC architectures is extremely heterogeneous. In this context, code portability is increasingly important for easy maintainability of applications; this is relevant in scientific computing where code changes are numerous and frequent. In this talk we present the design and optimization of a state-of-the-art production level LQCD Monte Carlo application, using the OpenACC directives model. OpenACC aims to abstract parallel programming to a descriptive level, where programmers do not need to specify the mapping of the code on the target machine. We describe the OpenACC implementation and show that the same code is able to target different architectures, including state-of-the-art CPUs and GPUs.

  15. KINETICS OF CHROMATE REDUCTION DURING NAPHTHALENE DEGRADATION IN A MIXED CULTURE

    EPA Science Inventory

    A mixed culture of Bacillus sp. K1 and Sphingomonas paucimobilis EPA 505 was exposed to chromate and naphthalene. Batch experiments showed that chromate was reduced and naphthalene was degraded by the mixed culture. Chromate reduction occurred initially at a high rate followed by...

  16. Delays in using chromatic and luminance information to correct rapid reaches.

    PubMed

    Kane, Adam; Wade, Alex; Ma-Wyatt, Anna

    2011-09-07

    People can use feedback to make online corrections to movements but only if there is sufficient time to integrate the new information and make the correction. A key variable in this process is therefore the speed at which the new information about the target location is coded. Conduction velocities for chromatic signals are lower than for achromatic signals so it may take longer to correct reaches to chromatic stimuli. In addition to this delay, the sensorimotor system may prefer achromatic information over the chromatic information as delayed information may be less valuable when movements are made under time pressure. A down-weighting of chromatic information may result in additional latencies for chromatically directed reaches. In our study, participants made online corrections to reaches to achromatic, (L-M)-cone, and S-cone stimuli. Our chromatic stimuli were carefully adjusted to minimize stimulation of achromatic pathways, and we equated stimuli both in terms of detection thresholds and also by their estimated neural responses. Similar stimuli were used throughout the subjective adjustments and final reaching experiment. Using this paradigm, we found that responses to achromatic stimuli were only slightly faster than responses to (L-M)-cone and S-cone stimuli. We conclude that the sensorimotor system treats chromatic and achromatic information similarly and that the delayed chromatic responses primarily reflect early conduction delays.

  17. Novel Perceptually Uniform Chromatic Space.

    PubMed

    da Fonseca, María; Samengo, Inés

    2018-06-01

    Chromatically perceptive observers are endowed with a sense of similarity between colors. For example, two shades of green that are only slightly discriminable are perceived as similar, whereas other pairs of colors, for example, blue and yellow, typically elicit markedly different sensations. The notion of similarity need not be shared by different observers. Dichromat and trichromat subjects perceive colors differently, and two dichromats (or two trichromats, for that matter) may judge chromatic differences inconsistently. Moreover, there is ample evidence that different animal species sense colors diversely. To capture the subjective metric of color perception, here we construct a notion of distance in color space based on the physiology of the retina, and is thereby individually tailored for different observers. By applying the Fisher metric to an analytical model of color representation, we construct a notion of distance that reproduces behavioral experiments of classical discrimination tasks. We then derive a coordinate transformation that defines a new chromatic space in which the Euclidean distance between any two colors is equal to the perceptual distance, as seen by one individual subject, endowed with an arbitrary number of color-sensitive photoreceptors, each with arbitrary absorption probability curves and appearing in arbitrary proportions.

  18. Study of chromatic adaptation via neutral white matches on different viewing media.

    PubMed

    Zhai, Qiyan; Luo, Ming R

    2018-03-19

    Two experiments were carried out to study the neutral white and the chromatic adaptation in human vision and color science. After matching neutral whites under different illuminants using both surface and self-luminous colors, the result were used to verify the previous study about the chromatic adaptation. Not all the white illuminants were found neutral even the adaptation time is long. The baseline illuminant of the two-step chromatic adaptation transform was found as the illuminant with the same chromaticity of the neutral white under it and depended on viewing medium in the present study. The results were also used as corresponding colors to derive models of the effective degree of chromatic adaptation, which were found highly associated with the chromaticity of the adapting illuminant.

  19. Chromatic-achromatic perimetry in four clinic cases: Glaucoma and diabetes.

    PubMed

    Cabezos, Inmaculada; Luque, Maria Jos; de Fez, Dolores; Moncho, Vicenta; Camps, Vicente

    2015-02-01

    Some diseases that affect the visual system may show loss of chromatic-achromatic sensitivity before obvious physical signs appear in the usual examination of the eye's posterior segment. A perimetric study has been conducted with four typical patients with glaucoma and diabetes, at different stages of the disease. In addition to the standard white-on-white (standard automated perimetry [SAP]), a test battery has been used to study patient's contrast sensitivity, using stimuli with different chromatic, spatial, and temporal content (multichannel perimetry). The choice of stimuli tries to maximize the response of different visual mechanisms: Achromatic (parvocellular and magnocellular origin); chromatic red-green (parvocellular origin); and chromatic blue-yellow (koniocellular origin). The results seem to indicate losses in the achromatic-parvocellular perimetry and both chromatic perimetry tests, undetected by conventional SAP. Our results illustrate that our patients without visible retinal alterations show signs of suspicion in multichannel perimetry.

  20. Mapping chromatic pathways in the Drosophila visual system.

    PubMed

    Lin, Tzu-Yang; Luo, Jiangnan; Shinomiya, Kazunori; Ting, Chun-Yuan; Lu, Zhiyuan; Meinertzhagen, Ian A; Lee, Chi-Hon

    2016-02-01

    In Drosophila, color vision and wavelength-selective behaviors are mediated by the compound eye's narrow-spectrum photoreceptors R7 and R8 and their downstream medulla projection (Tm) neurons Tm5a, Tm5b, Tm5c, and Tm20 in the second optic neuropil or medulla. These chromatic Tm neurons project axons to a deeper optic neuropil, the lobula, which in insects has been implicated in processing and relaying color information to the central brain. The synaptic targets of the chromatic Tm neurons in the lobula are not known, however. Using a modified GFP reconstitution across synaptic partners (GRASP) method to probe connections between the chromatic Tm neurons and 28 known and novel types of lobula neurons, we identify anatomically the visual projection neurons LT11 and LC14 and the lobula intrinsic neurons Li3 and Li4 as synaptic targets of the chromatic Tm neurons. Single-cell GRASP analyses reveal that Li4 receives synaptic contacts from over 90% of all four types of chromatic Tm neurons, whereas LT11 is postsynaptic to the chromatic Tm neurons, with only modest selectivity and at a lower frequency and density. To visualize synaptic contacts at the ultrastructural level, we develop and apply a "two-tag" double-labeling method to label LT11's dendrites and the mitochondria in Tm5c's presynaptic terminals. Serial electron microscopic reconstruction confirms that LT11 receives direct contacts from Tm5c. This method would be generally applicable to map the connections of large complex neurons in Drosophila and other animals. © 2015 Wiley Periodicals, Inc.

  1. Bandwidth correction for LED chromaticity based on Levenberg-Marquardt algorithm

    NASA Astrophysics Data System (ADS)

    Huang, Chan; Jin, Shiqun; Xia, Guo

    2017-10-01

    Light emitting diode (LED) is widely employed in industrial applications and scientific researches. With a spectrometer, the chromaticity of LED can be measured. However, chromaticity shift will occur due to the broadening effects of the spectrometer. In this paper, an approach is put forward to bandwidth correction for LED chromaticity based on Levenberg-Marquardt algorithm. We compare chromaticity of simulated LED spectra by using the proposed method and differential operator method to bandwidth correction. The experimental results show that the proposed approach achieves an excellent performance in bandwidth correction which proves the effectiveness of the approach. The method has also been tested on true blue LED spectra.

  2. On the locating-chromatic number for graphs with two homogenous components

    NASA Astrophysics Data System (ADS)

    Welyyanti, Des; Baskoro, Edy Tri; Simajuntak, Rinovia; Uttunggadewa, Saladin

    2017-10-01

    The locating-chromatic number of a graph was introduced by Chartrand et al. in 2002. The concept of the locating-chromatic number is a marriage between graph coloring and the notion of graph partition dimension. This concept is only for connected graphs. In [8], we extended this concept also for disconnected graphs. In this paper, we determine the locating- chromatic number of a graph with two components. In particular, we determine such values if the components are homogeneous and each component has locating-chromatic number 3.

  3. Spectroscopic On-Line Monitoring of Cu/W Contacts Erosion in HVCBs Using Optical-Fibre Based Sensor and Chromatic Methodology.

    PubMed

    Wang, Zhixiang; Jones, Gordon R; Spencer, Joseph W; Wang, Xiaohua; Rong, Mingzhe

    2017-03-06

    Contact erosion is one of the most crucial factors affecting the electrical service lifetime of high-voltage circuit breakers (HVCBs). On-line monitoring the contacts' erosion degree is increasingly in demand for the sake of condition based maintenance to guarantee the functional operation of HVCBs. A spectroscopic monitoring system has been designed based upon a commercial 245 kV/40 kA S F 6 live tank circuit breaker with copper-tungsten (28 wt % and 72 wt %) arcing contacts at atmospheric S F 6 pressure. Three optical-fibre based sensors are used to capture the time-resolved spectra of arcs. A novel approach using chromatic methods to process the time-resolved spectral signal has been proposed. The processed chromatic parameters have been interpreted to show that the time variation of spectral emission from the contact material and quenching gas are closely correlated to the mass loss and surface degradation of the plug arcing contact. The feasibility of applying this method to online monitoring of contact erosion is indicated.

  4. Chromatic confocal microscope using hybrid aspheric diffractive lenses

    NASA Astrophysics Data System (ADS)

    Rayer, Mathieu; Mansfield, Daniel

    2014-05-01

    A chromatic confocal microscope is a single point non-contact distance measurement sensor. For three decades the vast majority of the chromatic confocal microscope use refractive-based lenses to code the measurement axis chromatically. However, such an approach is limiting the range of applications. In this paper the performance of refractive, diffractive and Hybrid aspheric diffractive are compared. Hybrid aspheric diffractive lenses combine the low geometric aberration of a diffractive lens with the high optical power of an aspheric lens. Hybrid aspheric diffractive lenses can reduce the number of elements in an imaging system significantly or create large hyper- chromatic lenses for sensing applications. In addition, diffractive lenses can improve the resolution and the dynamic range of a chromatic confocal microscope. However, to be suitable for commercial applications, the diffractive optical power must be significant. Therefore, manufacturing such lenses is a challenge. We show in this paper how a theoretical manufacturing model can demonstrate that the hybrid aspheric diffractive configuration with the best performances is achieved by step diffractive surface. The high optical quality of step diffractive surface is then demonstrated experimentally. Publisher's Note: This paper, originally published on 5/10/14, was replaced with a corrected/revised version on 5/19/14. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.

  5. ACC Study Guide Series.

    ERIC Educational Resources Information Center

    Austin Community Coll., TX. Rio Grande Campus.

    Ten one-page instructional guides designed to assist Austin Community College (ACC) students in using the library and in writing research papers are presented in this series. The titles of the guides are: (1) "The Media Collection (We have more than books in the LRC)"; (2) "Encyclopedias"; (3) "Finding Books"; (4)…

  6. Chromatic blur perception in the presence of luminance contrast.

    PubMed

    Jennings, Ben J; Kingdom, Frederick A A

    2017-06-01

    Hel-Or showed that blurring the chromatic but not the luminance layer of an image of a natural scene failed to elicit any impression of blur. Subsequent studies have suggested that this effect is due either to chromatic blur being masked by spatially contiguous luminance edges in the scene (Journal of Vision 13 (2013) 14), or to a relatively compressed transducer function for chromatic blur (Journal of Vision 15 (2015) 6). To test between the two explanations we conducted experiments using as stimuli both images of natural scenes as well as simple edges. First, we found that in color-and-luminance images of natural scenes more chromatic blur was needed to perceptually match a given level of blur in an isoluminant, i.e. colour-only scene. However, when the luminance layer in the scene was rotated relative to the chromatic layer, thus removing the colour-luminance edge correlations, the matched blur levels were near equal. Both results are consistent with Sharman et al.'s explanation. Second, when observers matched the blurs of luminance-only with isoluminant scenes, the matched blurs were equal, against Kingdom et al.'s prediction. Third, we measured the perceived blur in a square-wave as a function of (i) contrast (ii) number of luminance edges and (iii) the relative spatial phase between the colour and luminance edges. We found that the perceived chromatic blur was dependent on both relative phase and the number of luminance edges, or dependent on the luminance contrast if only a single edge is present. We conclude that this Hel-Or effect is largely due to masking of chromatic blur by spatially contiguous luminance edges. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Semantics of color in chromatism

    NASA Astrophysics Data System (ADS)

    Serov, Nikolai V.

    2002-06-01

    The aim of this investigation is to describe the semantics of color in chromatism (from the ancient Greek triune notion of <>: (1) color as ideal (Id- plan), psychic; (2) tint as physical, verbal; material (M- plan), physiological, syntonic (S-plan), and (3) emotion as their informative-energetic correlation). Being a new field of science, chromatism links humanitarian and natural subjects by means of interdiscipline investigation of a real (f-m) man living in a real (color) surrounding environment. According to the definition for <>, color may be considered to be the most universal notion, permitting to assume the unity of both a man and an environment. Due to this assumption, we may give models of human intellect.

  8. Ethylene and 1-Aminocyclopropane-1-carboxylate (ACC) in Plant–Bacterial Interactions

    PubMed Central

    Nascimento, Francisco X.; Rossi, Márcio J.; Glick, Bernard R.

    2018-01-01

    Ethylene and its precursor 1-aminocyclopropane-1-carboxylate (ACC) actively participate in plant developmental, defense and symbiotic programs. In this sense, ethylene and ACC play a central role in the regulation of bacterial colonization (rhizospheric, endophytic, and phyllospheric) by the modulation of plant immune responses and symbiotic programs, as well as by modulating several developmental processes, such as root elongation. Plant-associated bacterial communities impact plant growth and development, both negatively (pathogens) and positively (plant-growth promoting and symbiotic bacteria). Some members of the plant-associated bacterial community possess the ability to modulate plant ACC and ethylene levels and, subsequently, modify plant defense responses, symbiotic programs and overall plant development. In this work, we review and discuss the role of ethylene and ACC in several aspects of plant-bacterial interactions. Understanding the impact of ethylene and ACC in both the plant host and its associated bacterial community is key to the development of new strategies aimed at increased plant growth and protection. PMID:29520283

  9. Form and toxicity of copper released into marine systems from ...

    EPA Pesticide Factsheets

    The fate and effects of pristine engineered nanomaterials (ENMs) in simplified systems have been widely studied; however, little is known about the potential release and impact of ENMs from consumer goods, especially lumber that has been treated with micronized copper. Micronized copper solutions contain copper complexes predominately in the 10-700 nm size range, and are used in lumber to prevent microbial degradation and fouling. In this work, the goal was to determine the rate, concentration, and form of copper released from commercially available pressure treated lumber samples (blocks and sawdust) exposed to an aqueous system. Lumber tested included Southern Yellow Pine (SYP) treated with micronized copper azole (MCA) at 0.96 and 2.4 Kg/m3, alkaline copper quaternary (ACQ) at 0.30 and 9.6 Kg/m3, and chromated copper arsenate (CCA) at 40 Kg/m3. Of the different chemical treatments, only MCA included nano- and micro-sized copper complexes. The experimental system included wood cubes cut from the outer 2 cm surface of the lumber or the equivalent mass (4 g) of sawdust submerged in 250 mL of media (0, 1, 10, and 30 ppt filtered natural seawater) in polyethylene bottles, and mixed on a shaker table at 120 rpm. Water samples were taken at 8 hours, and on days 1, 2, 7, 14, and 28 for the blocks and days 1, 2, 3, 7, 17, and 28 for the sawdust. Subsamples included unfiltered water (defined as 0.45 µm - filtered water for the sawdust), and water filtered through a 0.

  10. 24 CFR 969.107 - HUD approval of demolition or disposition before ACC expiration.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... disposition before ACC expiration. 969.107 Section 969.107 Housing and Urban Development Regulations Relating... before ACC expiration. This part is not intended to preclude or restrict the demolition or disposition of... before the ACC Expiration Date. ...

  11. Independence and interaction of luminance and chromatic contributions to spatial hyperacuity performance.

    PubMed

    Cooper, Bonnie; Lee, Barry B

    2014-04-01

    Here we test interactions of luminance and chromatic input to spatial hyperacuity mechanisms. First, we tested alignment of luminance and chromatic gratings matched or mismatched in contrast polarity or grating type. Thresholds with matched gratings were low while all mismatched pairs were elevated. Second, we determined alignment acuity as a function of luminance or chromatic contrast alone or in the presence of constant contrast components of the other type. For in-phase components, performance followed the envelope of the more sensitive mechanism. However, polarity reversals revealed an asymmetric effect for luminance and chromatic conditions, which suggested that luminance can override chromatic mechanisms in hyperacuity; we interpret these findings in the context of spatial mechanisms.

  12. Tone-Evoked Acoustic Change Complex (ACC) Recorded in a Sedated Animal Model.

    PubMed

    Presacco, Alessandro; Middlebrooks, John C

    2018-05-10

    The acoustic change complex (ACC) is a scalp-recorded cortical evoked potential complex generated in response to changes (e.g., frequency, amplitude) in an auditory stimulus. The ACC has been well studied in humans, but to our knowledge, no animal model has been evaluated. In particular, it was not known whether the ACC could be recorded under the conditions of sedation that likely would be necessary for recordings from animals. For that reason, we tested the feasibility of recording ACC from sedated cats in response to changes of frequency and amplitude of pure-tone stimuli. Cats were sedated with ketamine and acepromazine, and subdermal needle electrodes were used to record electroencephalographic (EEG) activity. Tones were presented from a small loudspeaker located near the right ear. Continuous tones alternated at 500-ms intervals between two frequencies or two levels. Neurometric functions were created by recording neural response amplitudes while systematically varying the magnitude of steps in frequency centered in octave frequency around 2, 4, 8, and 16 kHz, all at 75 dB SPL, or in decibel level around 75 dB SPL tested at 4 and 8 kHz. The ACC could be recorded readily under this ketamine/azepromazine sedation. In contrast, ACC could not be recorded reliably under any level of isoflurane anesthesia that was tested. The minimum frequency (expressed as Weber fractions (df/f)) or level steps (expressed in dB) needed to elicit ACC fell in the range of previous thresholds reported in animal psychophysical tests of discrimination. The success in recording ACC in sedated animals suggests that the ACC will be a useful tool for evaluation of other aspects of auditory acuity in normal hearing and, presumably, in electrical cochlear stimulation, especially for novel stimulation modes that are not yet feasible in humans.

  13. 24 CFR 969.106 - ACC extension in absence of current operating subsidy.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false ACC extension in absence of current... COMPLETION OF DEBT SERVICE § 969.106 ACC extension in absence of current operating subsidy. Where Operating Subsidy under an ACC is not approved for payment during a time period which results in extension of the...

  14. 24 CFR 969.106 - ACC extension in absence of current operating subsidy.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false ACC extension in absence of current... COMPLETION OF DEBT SERVICE § 969.106 ACC extension in absence of current operating subsidy. Where Operating Subsidy under an ACC is not approved for payment during a time period which results in extension of the...

  15. OpenARC: Extensible OpenACC Compiler Framework for Directive-Based Accelerator Programming Study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, Seyong; Vetter, Jeffrey S

    2014-01-01

    Directive-based, accelerator programming models such as OpenACC have arisen as an alternative solution to program emerging Scalable Heterogeneous Computing (SHC) platforms. However, the increased complexity in the SHC systems incurs several challenges in terms of portability and productivity. This paper presents an open-sourced OpenACC compiler, called OpenARC, which serves as an extensible research framework to address those issues in the directive-based accelerator programming. This paper explains important design strategies and key compiler transformation techniques needed to implement the reference OpenACC compiler. Moreover, this paper demonstrates the efficacy of OpenARC as a research framework for directive-based programming study, by proposing andmore » implementing OpenACC extensions in the OpenARC framework to 1) support hybrid programming of the unified memory and separate memory and 2) exploit architecture-specific features in an abstract manner. Porting thirteen standard OpenACC programs and three extended OpenACC programs to CUDA GPUs shows that OpenARC performs similarly to a commercial OpenACC compiler, while it serves as a high-level research framework.« less

  16. Steady-state kinetics of substrate binding and iron release in tomato ACC oxidase.

    PubMed

    Thrower, J S; Blalock, R; Klinman, J P

    2001-08-14

    1-Aminocyclopropane-1-carboxylate oxidase (ACC oxidase) catalyzes the last step in the biosynthetic pathway of the plant hormone, ethylene. This unusual reaction results in the oxidative ring cleavage of 1-aminocyclopropane carboxylate (ACC) into ethylene, cyanide, and CO2 and requires ferrous ion, ascorbate, and molecular oxygen for catalysis. A new purification procedure and assay method have been developed for tomato ACC oxidase that result in greatly increased enzymatic activity. This method allowed us to determine the rate of iron release from the enzyme and the effect of the activator, CO2, on this rate. Initial velocity studies support an ordered kinetic mechanism where ACC binds first followed by O2; ascorbate can bind after O2 or possibly before ACC. This kinetic mechanism differs from one recently proposed for the ACC oxidase from avocado.

  17. Color constancy by characterization of illumination chromaticity

    NASA Astrophysics Data System (ADS)

    Nikkanen, Jarno T.

    2011-05-01

    Computational color constancy algorithms play a key role in achieving desired color reproduction in digital cameras. Failure to estimate illumination chromaticity correctly will result in invalid overall colour cast in the image that will be easily detected by human observers. A new algorithm is presented for computational color constancy. Low computational complexity and low memory requirement make the algorithm suitable for resource-limited camera devices, such as consumer digital cameras and camera phones. Operation of the algorithm relies on characterization of the range of possible illumination chromaticities in terms of camera sensor response. The fact that only illumination chromaticity is characterized instead of the full color gamut, for example, increases robustness against variations in sensor characteristics and against failure of diagonal model of illumination change. Multiple databases are used in order to demonstrate the good performance of the algorithm in comparison to the state-of-the-art color constancy algorithms.

  18. REDUCTIVE DETOXIFICATION AND IMMOBILIZATION OF CHROMATE PRESENT IN SOILS

    EPA Science Inventory

    The in-situ permeable reactive barrier at the U.S. Coast Guard Air Support Center at Elizabeth City, North Carolina is very effective in remediating the contaminant plumes of TCE and chromate in the ground water, but it has limited effectiveness to attenuate chromate present as s...

  19. In vivo chromatic aberration in eyes implanted with intraocular lenses.

    PubMed

    Pérez-Merino, Pablo; Dorronsoro, Carlos; Llorente, Lourdes; Durán, Sonia; Jiménez-Alfaro, Ignacio; Marcos, Susana

    2013-04-12

    To measure in vivo and objectively the monochromatic aberrations at different wavelengths, and the chromatic difference of focus between green and infrared wavelengths in eyes implanted with two models of intraocular lenses (IOL). EIGHTEEN EYES PARTICIPATED IN THIS STUDY: nine implanted with Tecnis ZB99 1-Piece acrylic IOL and nine implanted with AcrySof SN60WF IOL. A custom-developed laser ray tracing (LRT) aberrometer was used to measure the optical aberrations, at 532 nm and 785 nm wavelengths. The monochromatic wave aberrations were described using a fifth-order Zernike polynomial expansion. The chromatic difference of focus was estimated as the difference between the equivalent spherical errors corresponding to each wavelength. Wave aberration measurements were highly reproducible. Except for the defocus term, no significant differences in high order aberrations (HOA) were found between wavelengths. The average chromatic difference of focus was 0.46 ± 0.15 diopters (D) in the Tecnis group, and 0.75 ± 0.12 D in the AcrySof group, and the difference was statistically significant (P < 0.05). Chromatic difference of focus in the AcrySof group was not statistically significantly different from the Longitudinal chromatic aberration (LCA) previously reported in a phakic population (0.78 ± 0.16 D). The impact of LCA on retinal image quality (measured in terms of Strehl ratio) was drastically reduced when considering HOA and astigmatism in comparison with a diffraction-limited eye, yielding the differences in retinal image quality between Tecnis and AcrySof IOLs not significant. LRT aberrometry at different wavelengths is a reproducible technique to evaluate the chromatic difference of focus objectively in eyes implanted with IOLs. Replacement of the crystalline lens by the IOL did not increase chromatic difference of focus above that of phakic eyes in any of the groups. The AcrySof group showed chromatic difference of focus values very similar to physiological

  20. Stereo chromatic contrast sensitivity model to blue-yellow gratings.

    PubMed

    Yang, Jiachen; Lin, Yancong; Liu, Yun

    2016-03-07

    As a fundamental metric of human visual system (HVS), contrast sensitivity function (CSF) is typically measured by sinusoidal gratings at the detection of thresholds for psychophysically defined cardinal channels: luminance, red-green, and blue-yellow. Chromatic CSF, which is a quick and valid index to measure human visual performance and various retinal diseases in two-dimensional (2D) space, can not be directly applied into the measurement of human stereo visual performance. And no existing perception model considers the influence of chromatic CSF of inclined planes on depth perception in three-dimensional (3D) space. The main aim of this research is to extend traditional chromatic contrast sensitivity characteristics to 3D space and build a model applicable in 3D space, for example, strengthening stereo quality of 3D images. This research also attempts to build a vision model or method to check human visual characteristics of stereo blindness. In this paper, CRT screen was clockwise and anti-clockwise rotated respectively to form the inclined planes. Four inclined planes were selected to investigate human chromatic vision in 3D space and contrast threshold of each inclined plane was measured with 18 observers. Stimuli were isoluminant blue-yellow sinusoidal gratings. Horizontal spatial frequencies ranged from 0.05 to 5 c/d. Contrast sensitivity was calculated as the inverse function of the pooled cone contrast threshold. According to the relationship between spatial frequency of inclined plane and horizontal spatial frequency, the chromatic contrast sensitivity characteristics in 3D space have been modeled based on the experimental data. The results show that the proposed model can well predicted human chromatic contrast sensitivity characteristics in 3D space.

  1. Spatio-Chromatic Adaptation via Higher-Order Canonical Correlation Analysis of Natural Images

    PubMed Central

    Gutmann, Michael U.; Laparra, Valero; Hyvärinen, Aapo; Malo, Jesús

    2014-01-01

    Independent component and canonical correlation analysis are two general-purpose statistical methods with wide applicability. In neuroscience, independent component analysis of chromatic natural images explains the spatio-chromatic structure of primary cortical receptive fields in terms of properties of the visual environment. Canonical correlation analysis explains similarly chromatic adaptation to different illuminations. But, as we show in this paper, neither of the two methods generalizes well to explain both spatio-chromatic processing and adaptation at the same time. We propose a statistical method which combines the desirable properties of independent component and canonical correlation analysis: It finds independent components in each data set which, across the two data sets, are related to each other via linear or higher-order correlations. The new method is as widely applicable as canonical correlation analysis, and also to more than two data sets. We call it higher-order canonical correlation analysis. When applied to chromatic natural images, we found that it provides a single (unified) statistical framework which accounts for both spatio-chromatic processing and adaptation. Filters with spatio-chromatic tuning properties as in the primary visual cortex emerged and corresponding-colors psychophysics was reproduced reasonably well. We used the new method to make a theory-driven testable prediction on how the neural response to colored patterns should change when the illumination changes. We predict shifts in the responses which are comparable to the shifts reported for chromatic contrast habituation. PMID:24533049

  2. Spatio-chromatic adaptation via higher-order canonical correlation analysis of natural images.

    PubMed

    Gutmann, Michael U; Laparra, Valero; Hyvärinen, Aapo; Malo, Jesús

    2014-01-01

    Independent component and canonical correlation analysis are two general-purpose statistical methods with wide applicability. In neuroscience, independent component analysis of chromatic natural images explains the spatio-chromatic structure of primary cortical receptive fields in terms of properties of the visual environment. Canonical correlation analysis explains similarly chromatic adaptation to different illuminations. But, as we show in this paper, neither of the two methods generalizes well to explain both spatio-chromatic processing and adaptation at the same time. We propose a statistical method which combines the desirable properties of independent component and canonical correlation analysis: It finds independent components in each data set which, across the two data sets, are related to each other via linear or higher-order correlations. The new method is as widely applicable as canonical correlation analysis, and also to more than two data sets. We call it higher-order canonical correlation analysis. When applied to chromatic natural images, we found that it provides a single (unified) statistical framework which accounts for both spatio-chromatic processing and adaptation. Filters with spatio-chromatic tuning properties as in the primary visual cortex emerged and corresponding-colors psychophysics was reproduced reasonably well. We used the new method to make a theory-driven testable prediction on how the neural response to colored patterns should change when the illumination changes. We predict shifts in the responses which are comparable to the shifts reported for chromatic contrast habituation.

  3. Accommodative performance for chromatic displays.

    PubMed

    Lovasik, J V; Kergoat, H

    1988-01-01

    Over the past few years, video display units (VDUs) have been incorporated into many varieties of workplaces and occupational demands. The success of electro-optical displays in facilitating and improving job performance has spawned interest in extracting further advantage from VDUs by incorporating colour coding into such communication systems. However, concerns have been raised about the effect of chromatic stimuli on the visual comfort and task efficiency, because of the chromatic aberration inherent in the optics of the human eye. In this study, we used a computer aided laser speckle optometer system to measure the accommodative responses to brightness-matched chromatic letters displayed on a high-resolution RGB monitor. Twenty, visually normal, paid volunteers in a 22-35 year age category served as subjects. Stimuli were 14, 21, 28 minutes of arc letters presented in a 'monochromatic' (white, red, green or blue, on a black background) or 'multichromatic' (blue-red, blue-green, red-green, foreground-background combinations) mode at 40 and 80 cm viewing distances. The results demonstrated that while the accommodative responses were strongly influenced by the foreground-background colour combination, the group-averaged dioptric difference across colours was relatively small. Further, accommodative responses were not guided in any systematic fashion by the size of letters presented for fixation. Implications of these findings for display designs are discussed.

  4. Color-motion feature-binding errors are mediated by a higher-order chromatic representation.

    PubMed

    Shevell, Steven K; Wang, Wei

    2016-03-01

    Peripheral and central moving objects of the same color may be perceived to move in the same direction even though peripheral objects have a different true direction of motion [Nature429, 262 (2004)10.1038/429262a]. The perceived, illusory direction of peripheral motion is a color-motion feature-binding error. Recent work shows that such binding errors occur even without an exact color match between central and peripheral objects, and, moreover, the frequency of the binding errors in the periphery declines as the chromatic difference increases between the central and peripheral objects [J. Opt. Soc. Am. A31, A60 (2014)JOAOD60740-323210.1364/JOSAA.31.000A60]. This change in the frequency of binding errors with the chromatic difference raises the general question of the chromatic representation from which the difference is determined. Here, basic properties of the chromatic representation are tested to discover whether it depends on independent chromatic differences on the l and the s cardinal axes or, alternatively, on a more specific higher-order chromatic representation. Experimental tests compared the rate of feature-binding errors when the central and peripheral colors had the identical s chromaticity (so zero difference in s) and a fixed magnitude of l difference, while varying the identical s level in center and periphery (thus always keeping the s difference at zero). A chromatic representation based on independent l and s differences would result in the same frequency of color-motion binding errors at everyslevel. The results are contrary to this prediction, thus showing that the chromatic representation at the level of color-motion feature binding depends on a higher-order chromatic mechanism.

  5. Color-motion feature-binding errors are mediated by a higher-order chromatic representation

    PubMed Central

    Shevell, Steven K.; Wang, Wei

    2017-01-01

    Peripheral and central moving objects of the same color may be perceived to move in the same direction even though peripheral objects have a different true direction of motion [Nature 429, 262 (2004)]. The perceived, illusory direction of peripheral motion is a color-motion feature-binding error. Recent work shows that such binding errors occur even without an exact color match between central and peripheral objects, and, moreover, the frequency of the binding errors in the periphery declines as the chromatic difference increases between the central and peripheral objects [J. Opt. Soc. Am. A 31, A60 (2014)]. This change in the frequency of binding errors with the chromatic difference raises the general question of the chromatic representation from which the difference is determined. Here, basic properties of the chromatic representation are tested to discover whether it depends on independent chromatic differences on the l and the s cardinal axes or, alternatively, on a more specific higher-order chromatic representation. Experimental tests compared the rate of feature-binding errors when the central and peripheral colors had the identical s chromaticity (so zero difference in s) and a fixed magnitude of l difference, while varying the identical s level in center and periphery (thus always keeping the s difference at zero). A chromatic representation based on independent l and s differences would result in the same frequency of color-motion binding errors at every s level. The results are contrary to this prediction, thus showing that the chromatic representation at the level of color-motion feature binding depends on a higherorder chromatic mechanism. PMID:26974945

  6. 24 CFR 882.805 - HA application process, ACC execution, and pre-rehabilitation activities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false HA application process, ACC... § 882.805 HA application process, ACC execution, and pre-rehabilitation activities. (a) Review. When... applications in accordance with the guidelines, rating criteria, and procedures published in the NOFA. (b) ACC...

  7. In vitro synthesis and stabilization of amorphous calcium carbonate (ACC) nanoparticles within liposomes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tester, Chantel C.; Brock, Ryan E.; Wu, Ching-Hsuan

    2012-02-07

    We show that amorphous calcium carbonate (ACC) can be synthesized in phospholipid bilayer vesicles (liposomes). Liposome-encapsulated ACC nanoparticles are stable against aggregation, do not crystallize for at least 20 h, and are ideally suited to investigate the influence of lipid chemistry, particle size, and soluble additives on ACC in situ.

  8. 24 CFR 969.107 - HUD approval of demolition or disposition before ACC expiration.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... disposition before ACC expiration. 969.107 Section 969.107 Housing and Urban Development REGULATIONS RELATING... HOUSING AFTER COMPLETION OF DEBT SERVICE § 969.107 HUD approval of demolition or disposition before ACC..., HUD may authorize a PHA to demolish or dispose of public housing at any time before the ACC Expiration...

  9. The Repeat Sequences and Elevated Substitution Rates of the Chloroplast accD Gene in Cupressophytes

    PubMed Central

    Li, Jia; Su, Yingjuan; Wang, Ting

    2018-01-01

    The plastid accD gene encodes a subunit of the acetyl-CoA carboxylase (ACCase) enzyme. The length of accD gene has been supposed to expand in Cryptomeria japonica, Taiwania cryptomerioides, Cephalotaxus, Taxus chinensis, and Podocarpus lambertii, and the main reason for this phenomenon was the existence of tandemly repeated sequences. However, it is still unknown whether the accD gene length in other cupressophytes has expanded. Here, in order to investigate how widespread this phenomenon was, 18 accD sequences and its surrounding regions of cupressophyte were sequenced and analyzed. Together with 39 GenBank sequence data, our taxon sampling covered all the extant gymnosperm orders. The repetitive elements and substitution rates of accD among 57 gymnosperm species were analyzed, the results show: (1) Reading frame length of accD gene in 18 cupressophytes species has also expanded. (2) Many repetitive elements were identified in accD gene of cupressophyte lineages. (3) The synonymous and non-synonymous substitution rates of accD were accelerated in cupressophytes. (4) accD was located in rearrangement endpoints. These results suggested that repetitive elements may mediate the chloroplast genome rearrangement and accelerated the substitution rates. PMID:29731764

  10. Chromatic characterization of a three-channel colorimeter using back-propagation neural networks

    NASA Astrophysics Data System (ADS)

    Pardo, P. J.; Pérez, A. L.; Suero, M. I.

    2004-09-01

    This work describes a method for the chromatic characterization of a three-channel colorimeter of recent design and construction dedicated to color vision research. The colorimeter consists of two fixed monochromators and a third monochromator interchangeable with a cathode ray tube or any other external light source. Back-propagation neural networks were used for the chromatic characterization to establish the relationship between each monochromator's input parameters and the tristimulus values of each chromatic stimulus generated. The results showed the effectiveness of this type of neural-network-based system for the chromatic characterization of the stimuli produced by any monochromator.

  11. Non Chromate, ZVOC Coatings for Steel Substrates on Army and Navy Aircraft and Ground Vehicles: Non Chromate Sealers for Zinc Phosphate

    DTIC Science & Technology

    2017-04-30

    Defense, “Chemical Agent Resistant Coating (CARC) System Application Procedures and Quality Control Inspection”, Washington, DC, June 2003. 4. Non ...WP-200906) Non -Chromate, ZVOC Coatings for Steel Substrates on Army and Navy Aircraft and Ground Vehicles Non -Chromate Sealers for Zinc...comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE

  12. Measuring chromatic aberrations in imaging systems using plasmonic nanoparticles.

    PubMed

    Gennaro, Sylvain D; Roschuk, Tyler R; Maier, Stefan A; Oulton, Rupert F

    2016-04-01

    We demonstrate a method to measure chromatic aberrations of microscope objectives with metallic nanoparticles using white light. Extinction spectra are recorded while scanning a single nanoparticle through a lens's focal plane. We show a direct correlation between the focal wavelength and the longitudinal chromatic focal shift through our analysis of the variations between the scanned extinction spectra at each scan position and the peak extinction over the entire scan. The method has been tested on achromat and apochromat objectives using aluminum disks varying in size from 260-520 nm. Our method is straightforward, robust, low cost, and broadband with a sensitivity suitable for assessing longitudinal chromatic aberrations in high-numerical-aperture apochromatic corrected lenses.

  13. Recalibration of the ACC/AHA Risk Score in Two Population-Based German Cohorts

    PubMed Central

    de las Heras Gala, Tonia; Geisel, Marie Henrike; Peters, Annette; Thorand, Barbara; Baumert, Jens; Lehmann, Nils; Jöckel, Karl-Heinz; Moebus, Susanne; Erbel, Raimund; Meisinger, Christine

    2016-01-01

    Background The 2013 ACC/AHA guidelines introduced an algorithm for risk assessment of atherosclerotic cardiovascular disease (ASCVD) within 10 years. In Germany, risk assessment with the ESC SCORE is limited to cardiovascular mortality. Applicability of the novel ACC/AHA risk score to the German population has not yet been assessed. We therefore sought to recalibrate and evaluate the ACC/AHA risk score in two German cohorts and to compare it to the ESC SCORE. Methods We studied 5,238 participants from the KORA surveys S3 (1994–1995) and S4 (1999–2001) and 4,208 subjects from the Heinz Nixdorf Recall (HNR) Study (2000–2003). There were 383 (7.3%) and 271 (6.4%) first non-fatal or fatal ASCVD events within 10 years in KORA and in HNR, respectively. Risk scores were evaluated in terms of calibration and discrimination performance. Results The original ACC/AHA risk score overestimated 10-year ASCVD rates by 37% in KORA and 66% in HNR. After recalibration, miscalibration diminished to 8% underestimation in KORA and 12% overestimation in HNR. Discrimination performance of the ACC/AHA risk score was not affected by the recalibration (KORA: C = 0.78, HNR: C = 0.74). The ESC SCORE overestimated by 5% in KORA and by 85% in HNR. The corresponding C-statistic was 0.82 in KORA and 0.76 in HNR. Conclusions The recalibrated ACC/AHA risk score showed strongly improved calibration compared to the original ACC/AHA risk score. Predicting only cardiovascular mortality, discrimination performance of the commonly used ESC SCORE remained somewhat superior to the ACC/AHA risk score. Nevertheless, the recalibrated ACC/AHA risk score may provide a meaningful tool for estimating 10-year risk of fatal and non-fatal cardiovascular disease in Germany. PMID:27732641

  14. Recalibration of the ACC/AHA Risk Score in Two Population-Based German Cohorts.

    PubMed

    de Las Heras Gala, Tonia; Geisel, Marie Henrike; Peters, Annette; Thorand, Barbara; Baumert, Jens; Lehmann, Nils; Jöckel, Karl-Heinz; Moebus, Susanne; Erbel, Raimund; Meisinger, Christine; Mahabadi, Amir Abbas; Koenig, Wolfgang

    2016-01-01

    The 2013 ACC/AHA guidelines introduced an algorithm for risk assessment of atherosclerotic cardiovascular disease (ASCVD) within 10 years. In Germany, risk assessment with the ESC SCORE is limited to cardiovascular mortality. Applicability of the novel ACC/AHA risk score to the German population has not yet been assessed. We therefore sought to recalibrate and evaluate the ACC/AHA risk score in two German cohorts and to compare it to the ESC SCORE. We studied 5,238 participants from the KORA surveys S3 (1994-1995) and S4 (1999-2001) and 4,208 subjects from the Heinz Nixdorf Recall (HNR) Study (2000-2003). There were 383 (7.3%) and 271 (6.4%) first non-fatal or fatal ASCVD events within 10 years in KORA and in HNR, respectively. Risk scores were evaluated in terms of calibration and discrimination performance. The original ACC/AHA risk score overestimated 10-year ASCVD rates by 37% in KORA and 66% in HNR. After recalibration, miscalibration diminished to 8% underestimation in KORA and 12% overestimation in HNR. Discrimination performance of the ACC/AHA risk score was not affected by the recalibration (KORA: C = 0.78, HNR: C = 0.74). The ESC SCORE overestimated by 5% in KORA and by 85% in HNR. The corresponding C-statistic was 0.82 in KORA and 0.76 in HNR. The recalibrated ACC/AHA risk score showed strongly improved calibration compared to the original ACC/AHA risk score. Predicting only cardiovascular mortality, discrimination performance of the commonly used ESC SCORE remained somewhat superior to the ACC/AHA risk score. Nevertheless, the recalibrated ACC/AHA risk score may provide a meaningful tool for estimating 10-year risk of fatal and non-fatal cardiovascular disease in Germany.

  15. Driver's behavioral adaptation to adaptive cruise control (ACC): the case of speed and time headway.

    PubMed

    Bianchi Piccinini, Giulio Francesco; Rodrigues, Carlos Manuel; Leitão, Miguel; Simões, Anabela

    2014-06-01

    The Adaptive Cruise Control is an Advanced Driver Assistance System (ADAS) that allows maintaining given headway and speed, according to settings pre-defined by the users. Despite the potential benefits associated to the utilization of ACC, previous studies warned against negative behavioral adaptations that might occur while driving with the system activated. Unfortunately, up to now, there are no unanimous results about the effects induced by the usage of ACC on speed and time headway to the vehicle in front. Also, few studies were performed including actual users of ACC among the subjects. This research aimed to investigate the effect of the experience gained with ACC on speed and time headway for a group of users of the system. In addition, it explored the impact of ACC usage on speed and time headway for ACC users and regular drivers. A matched sample driving simulator study was planned as a two-way (2×2) repeated measures mixed design, with the experience with ACC as between-subjects factor and the driving condition (with ACC and manually) as within-subjects factor. The results show that the usage of ACC brought a small but not significant reduction of speed and, especially, the maintenance of safer time headways, being the latter result greater for ACC users, probably as a consequence of their experience in using the system. The usage of ACC did not cause any negative behavioral adaptations to the system regarding speed and time headway. Based on this research work, the Adaptive Cruise Control showed the potential to improve road safety for what concerns the speed and the time headway maintained by the drivers. The speed of the surrounding traffic and the minimum time headway settable through the ACC seem to have an important effect on the road safety improvement achievable with the system. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Chromatic Perceptual Learning but No Category Effects without Linguistic Input.

    PubMed

    Grandison, Alexandra; Sowden, Paul T; Drivonikou, Vicky G; Notman, Leslie A; Alexander, Iona; Davies, Ian R L

    2016-01-01

    Perceptual learning involves an improvement in perceptual judgment with practice, which is often specific to stimulus or task factors. Perceptual learning has been shown on a range of visual tasks but very little research has explored chromatic perceptual learning. Here, we use two low level perceptual threshold tasks and a supra-threshold target detection task to assess chromatic perceptual learning and category effects. Experiment 1 investigates whether chromatic thresholds reduce as a result of training and at what level of analysis learning effects occur. Experiment 2 explores the effect of category training on chromatic thresholds, whether training of this nature is category specific and whether it can induce categorical responding. Experiment 3 investigates the effect of category training on a higher level, lateralized target detection task, previously found to be sensitive to category effects. The findings indicate that performance on a perceptual threshold task improves following training but improvements do not transfer across retinal location or hue. Therefore, chromatic perceptual learning is category specific and can occur at relatively early stages of visual analysis. Additionally, category training does not induce category effects on a low level perceptual threshold task, as indicated by comparable discrimination thresholds at the newly learned hue boundary and adjacent test points. However, category training does induce emerging category effects on a supra-threshold target detection task. Whilst chromatic perceptual learning is possible, learnt category effects appear to be a product of left hemisphere processing, and may require the input of higher level linguistic coding processes in order to manifest.

  17. Chromatic Perceptual Learning but No Category Effects without Linguistic Input

    PubMed Central

    Grandison, Alexandra; Sowden, Paul T.; Drivonikou, Vicky G.; Notman, Leslie A.; Alexander, Iona; Davies, Ian R. L.

    2016-01-01

    Perceptual learning involves an improvement in perceptual judgment with practice, which is often specific to stimulus or task factors. Perceptual learning has been shown on a range of visual tasks but very little research has explored chromatic perceptual learning. Here, we use two low level perceptual threshold tasks and a supra-threshold target detection task to assess chromatic perceptual learning and category effects. Experiment 1 investigates whether chromatic thresholds reduce as a result of training and at what level of analysis learning effects occur. Experiment 2 explores the effect of category training on chromatic thresholds, whether training of this nature is category specific and whether it can induce categorical responding. Experiment 3 investigates the effect of category training on a higher level, lateralized target detection task, previously found to be sensitive to category effects. The findings indicate that performance on a perceptual threshold task improves following training but improvements do not transfer across retinal location or hue. Therefore, chromatic perceptual learning is category specific and can occur at relatively early stages of visual analysis. Additionally, category training does not induce category effects on a low level perceptual threshold task, as indicated by comparable discrimination thresholds at the newly learned hue boundary and adjacent test points. However, category training does induce emerging category effects on a supra-threshold target detection task. Whilst chromatic perceptual learning is possible, learnt category effects appear to be a product of left hemisphere processing, and may require the input of higher level linguistic coding processes in order to manifest. PMID:27252669

  18. Potential of Silanes for Chromate Replacement in Metal Finishing Industries

    DTIC Science & Technology

    2002-09-16

    POTENTIAL OF SILANES FOR CHROMATE REPLACEMENT IN METAL FINISHING INDUSTRIES Wim J. van Ooij*, Danqing Zhu, Vignesh Palanivel, J. Anna Lamar...18 2 POTENTIAL OF SILANES FOR CHROMATE REPLACEMENT IN METAL FINISHING INDUSTRIES Wim J. van Ooij, Danqing Zhu, Vignesh Palanivel, J. Anna Lamar

  19. Abnormal pupillary light reflex with chromatic pupillometry in Gaucher disease.

    PubMed

    Narita, Aya; Shirai, Kentarou; Kubota, Norika; Takayama, Rumiko; Takahashi, Yukitoshi; Onuki, Takanori; Numakura, Chikahiko; Kato, Mitsuhiro; Hamada, Yusuke; Sakai, Norio; Ohno, Atsuko; Asami, Maya; Matsushita, Shoko; Hayashi, Anri; Kumada, Tomohiro; Fujii, Tatsuya; Horino, Asako; Inoue, Takeshi; Kuki, Ichiro; Asakawa, Ken; Ishikawa, Hitoshi; Ohno, Koyo; Nishimura, Yoko; Tamasaki, Akiko; Maegaki, Yoshihiro; Ohno, Kousaku

    2014-02-01

    The hallmark of neuronopathic Gaucher disease (GD) is oculomotor abnormalities, but ophthalmological assessment is difficult in uncooperative patients. Chromatic pupillometry is a quantitative method to assess the pupillary light reflex (PLR) with minimal patient cooperation. Thus, we investigated whether chromatic pupillometry could be useful for neurological evaluations in GD. In our neuronopathic GD patients, red light-induced PLR was markedly impaired, whereas blue light-induced PLR was relatively spared. In addition, patients with non-neuronopathic GD showed no abnormalities. These novel findings show that chromatic pupillometry is a convenient method to detect neurological signs and monitor the course of disease in neuronopathic GD.

  20. Dynamics of chromatic visual system processing differ in complexity between children and adults.

    PubMed

    Boon, Mei Ying; Suttle, Catherine M; Henry, Bruce I; Dain, Stephen J

    2009-06-30

    Measures of chromatic contrast sensitivity in children are lower than those of adults. This may be related to immaturities in signal processing at or near threshold. We have found that children's VEPs in response to low contrast supra-threshold chromatic stimuli are more intra-individually variable than those recorded from adults. Here, we report on linear and nonlinear analyses of chromatic VEPs recorded from children and adults. Two measures of signal-to-noise ratio are similar between the adults and children, suggesting that relatively high noise is unlikely to account for the poor clarity of negative and positive peak components in the children's VEPs. Nonlinear analysis indicates higher complexity of adults' than children's chromatic VEPs, at levels of chromatic contrast around and well above threshold.

  1. Accommodation to wavefront vergence and chromatic aberration.

    PubMed

    Wang, Yinan; Kruger, Philip B; Li, James S; Lin, Peter L; Stark, Lawrence R

    2011-05-01

    Longitudinal chromatic aberration (LCA) provides a cue to accommodation with small pupils. However, large pupils increase monochromatic aberrations, which may obscure chromatic blur. In this study, we examined the effect of pupil size and LCA on accommodation. Accommodation was recorded by infrared optometer while observers (nine normal trichromats) viewed a sinusoidally moving Maltese cross target in a Badal stimulus system. There were two illumination conditions: white (3000 K; 20 cd/m) and monochromatic (550 nm with 10 nm bandwidth; 20 cd/m) and two artificial pupil conditions (3 and 5.7 mm). Separately, static measurements of wavefront aberration were made with the eye accommodating to targets between 0 and 4 D (COAS, Wavefront Sciences). Large individual differences in accommodation to wavefront vergence and to LCA are a hallmark of accommodation. LCA continues to provide a signal at large pupil sizes despite higher levels of monochromatic aberrations. Monochromatic aberrations may defend against chromatic blur at high spatial frequencies, but accommodation responds best to optical vergence and to LCA at 3 c/deg where blur from higher order aberrations is less.

  2. Chromate Dissociation from Primer Paint in Simulated Lung Fluid.

    DTIC Science & Technology

    2000-03-01

    not done properly. Chromium is found naturally in the earth’s crust; trivalent chromium is a necessary dietary mineral. Other oxidative states such...exposures to chromium can include welding , leather tanning, electroplating, textile manufacturing, photoengraving, copier servicing and paints/pigments...production, production of chromates and chromate pigments, leather tanning, chromium plating and welding . Unfortunately, no detailed health studies have

  3. Nonlocal interactions in color perception: nonlinear processing of chromatic signals from remote inducers.

    PubMed

    Wachtler, T; Albright, T D; Sejnowski, T J

    2001-05-01

    The perceived color of an object depends on the chromaticity of its immediate background. But color appearance is also influenced by remote chromaticities. To quantify these influences, the effects of remote color fields on the appearance of a fixated 2 degrees test field were measured using a forced-choice method. Changes in the appearance of the test field were induced by chromaticity changes of the background and of 2 degrees color fields not adjacent to the test field. The appearance changes induced by the color of the background corresponded to a fraction of between 0.5 and 0.95 of the cone contrast of the background change, depending on the observer. The magnitude of induction by the background color was modulated on average by 7.6% by chromaticity changes in the remote color fields. Chromaticity changes in the remote fields had virtually no inducing effect when they occurred without a change in background color. The spatial range of these chromatic interactions extended over at least 10 degrees from the fovea. They were established within the first few hundred milliseconds after the change of background color and depended only weakly on the number of inducing fields. These results may be interpreted as reflecting rapid chromatic interactions that support robustness of color vision under changing viewing conditions.

  4. Pigment tests evaluated by a model of chromatic discrimination.

    PubMed

    Smith, V C; Pokorny, J; Yeh, T

    1993-08-01

    Clinical color-vision tests are evaluated within the framework of a model of chromatic discrimination in terms of cone excitation. The motivation for this study was to derive a method for evaluation of test design, test sensitivity, and observer performance. The discrimination model is based on the assumption that chromatic discrimination is mediated in two independent channels, one for short-wavelength cones and one for long- and middle-wavelength cones. Luminance-dependent templates are derived for each channel, and they describe chromatic-discrimination behavior of the young color-normal observer. The templates incorporate receptor- and opponent-level gain controls. We show how the chromaticities of clinical tests can be calculated in cone-excitation units and how discrimination behavior on the tests can be plotted on the templates. The tests include the Farnsworth-Munsell 100-hue, the Farnsworth Panel D-15, the Farnsworth Panel D-15 desaturated, the American Optical Hardy-Rand-Rittler, the Farnsworth F2 plate, the Standard Pseudoisochromatic Plates, Part II, the Ishihara, and the Minimalist tests. Clinical-test data collected on young color-normal observers at different illumination levels show the validity of the techniques.

  5. Contrast gain control: a bilinear model for chromatic selectivity.

    PubMed

    Singer, B; D'Zmura, M

    1995-04-01

    We report the results of psychophysical experiments on color contrast induction. In earlier work [Vision Res. 34, 3111 (1994)], we showed that modulating the spatial contrast of an annulus in time induces an apparent modulation of the contrast of a central disk, at isoluminance. Here we vary the chromatic properties of disk and annulus systematically in a study of the interactions among the luminance and the color-opponent channels. Results show that induced contrast depends linearly on both disk and annulus contrast, at low and moderate contrast levels. This dependence leads us to propose a bilinear model for color contrast gain control. The model predicts the magnitude and the chromatic properties of induced contrast. In agreement with experimental results, the model displays chromatic selectivity in contrast gain control and a negligible effect of contrast modulation at isoluminance on the appearance of achromatic contrast. We show that the bilinear model for chromatic selectivity may be realized as a feed-forward multiplicative gain control. Data collected at high contrast levels are fit by embellishing the model with saturating nonlinearities in the contrast gain control of each color channel.

  6. Calculating correlated color temperatures across the entire gamut of daylight and skylight chromaticities.

    PubMed

    Hernández-Andrés, J; Lee, R L; Romero, J

    1999-09-20

    Natural outdoor illumination daily undergoes large changes in its correlated color temperature (CCT), yet existing equations for calculating CCT from chromaticity coordinates span only part of this range. To improve both the gamut and accuracy of these CCT calculations, we use chromaticities calculated from our measurements of nearly 7000 daylight and skylight spectra to test an equation that accurately maps CIE 1931 chromaticities x and y into CCT. We extend the work of McCamy [Color Res. Appl. 12, 285-287 (1992)] by using a chromaticity epicenter for CCT and the inverse slope of the line that connects it to x and y. With two epicenters for different CCT ranges, our simple equation is accurate across wide chromaticity and CCT ranges (3000-10(6) K) spanned by daylight and skylight.

  7. Replacement of chromates in paints and corrosion protection systems [Stage 2

    DOT National Transportation Integrated Search

    2004-05-01

    This technical report presents the second stage results of a multi-year project to develop chromate-free paints and corrosion protection systems. Chromate-containing coatings and paints are very effective in providing corrosion resistance and are wid...

  8. Abnormal pupillary light reflex with chromatic pupillometry in Gaucher disease

    PubMed Central

    Narita, Aya; Shirai, Kentarou; Kubota, Norika; Takayama, Rumiko; Takahashi, Yukitoshi; Onuki, Takanori; Numakura, Chikahiko; Kato, Mitsuhiro; Hamada, Yusuke; Sakai, Norio; Ohno, Atsuko; Asami, Maya; Matsushita, Shoko; Hayashi, Anri; Kumada, Tomohiro; Fujii, Tatsuya; Horino, Asako; Inoue, Takeshi; Kuki, Ichiro; Asakawa, Ken; Ishikawa, Hitoshi; Ohno, Koyo; Nishimura, Yoko; Tamasaki, Akiko; Maegaki, Yoshihiro; Ohno, Kousaku

    2014-01-01

    The hallmark of neuronopathic Gaucher disease (GD) is oculomotor abnormalities, but ophthalmological assessment is difficult in uncooperative patients. Chromatic pupillometry is a quantitative method to assess the pupillary light reflex (PLR) with minimal patient cooperation. Thus, we investigated whether chromatic pupillometry could be useful for neurological evaluations in GD. In our neuronopathic GD patients, red light-induced PLR was markedly impaired, whereas blue light-induced PLR was relatively spared. In addition, patients with non-neuronopathic GD showed no abnormalities. These novel findings show that chromatic pupillometry is a convenient method to detect neurological signs and monitor the course of disease in neuronopathic GD. PMID:25356393

  9. Very-long-term and short-term chromatic adaptation: are their influences cumulative?

    PubMed

    Belmore, Suzanne C; Shevell, Steven K

    2011-02-09

    Very-long-term (VLT) chromatic adaptation results from exposure to an altered chromatic environment for days or weeks. Color shifts from VLT adaptation are observed hours or days after leaving the altered environment. Short-term chromatic adaptation, on the other hand, results from exposure for a few minutes or less, with color shifts measured within seconds or a few minutes after the adapting light is extinguished; recovery to the pre-adapted state is complete in less than an hour. Here, both types of adaptation were combined. All adaptation was to reddish-appearing long-wavelength light. Shifts in unique yellow were measured following adaptation. Previous studies demonstrate shifts in unique yellow due to VLT chromatic adaptation, but shifts from short-term chromatic adaptation to comparable adapting light can be far greater than from VLT adaptation. The question considered here is whether the color shifts from VLT adaptation are cumulative with large shifts from short-term adaptation or, alternatively, does simultaneous short-term adaptation eliminate color shifts caused by VLT adaptation. The results show the color shifts from VLT and short-term adaptation together are cumulative, which indicates that both short-term and very-long-term chromatic adaptation affect color perception during natural viewing. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Primary chromatic aberration elimination via optimization work with genetic algorithm

    NASA Astrophysics Data System (ADS)

    Wu, Bo-Wen; Liu, Tung-Kuan; Fang, Yi-Chin; Chou, Jyh-Horng; Tsai, Hsien-Lin; Chang, En-Hao

    2008-09-01

    Chromatic Aberration plays a part in modern optical systems, especially in digitalized and smart optical systems. Much effort has been devoted to eliminating specific chromatic aberration in order to match the demand for advanced digitalized optical products. Basically, the elimination of axial chromatic and lateral color aberration of an optical lens and system depends on the selection of optical glass. According to reports from glass companies all over the world, the number of various newly developed optical glasses in the market exceeds three hundred. However, due to the complexity of a practical optical system, optical designers have so far had difficulty in finding the right solution to eliminate small axial and lateral chromatic aberration except by the Damped Least Squares (DLS) method, which is limited in so far as the DLS method has not yet managed to find a better optical system configuration. In the present research, genetic algorithms are used to replace traditional DLS so as to eliminate axial and lateral chromatic, by combining the theories of geometric optics in Tessar type lenses and a technique involving Binary/Real Encoding, Multiple Dynamic Crossover and Random Gene Mutation to find a much better configuration for optical glasses. By implementing the algorithms outlined in this paper, satisfactory results can be achieved in eliminating axial and lateral color aberration.

  11. Antimicrobial copper alloys decreased bacteria on stethoscope surfaces.

    PubMed

    Schmidt, Michael G; Tuuri, Rachel E; Dharsee, Arif; Attaway, Hubert H; Fairey, Sarah E; Borg, Keith T; Salgado, Cassandra D; Hirsch, Bruce E

    2017-06-01

    Stethoscopes may serve as vehicles for transmission of bacteria among patients. The aim of this study was to assess the efficacy of antimicrobial copper surfaces to reduce the bacterial concentration associated with stethoscope surfaces. A structured prospective trial involving 21 health care providers was conducted at a pediatric emergency division (ED) (n = 14) and an adult medical intensive care unit located in tertiary care facilities (n = 7). Four surfaces common to a stethoscope and a facsimile instrument fabricated from U.S. Environmental Protection Agency-registered antimicrobial copper alloys (AMCus) were assessed for total aerobic colony counts (ACCs), methicillin-resistant Staphylococcus aureus, gram-negative bacteria, and vancomycin-resistant enterococci for 90 days. The mean ACCs collectively recovered from all stethoscope surfaces fabricated from the AMCus were found to carry significantly lower concentrations of bacteria (pediatric ED, 11.7 vs 127.1 colony forming units [CFU]/cm 2 , P < .00001) than their control equivalents. This observation was independent of health care provider or infection control practices. Absence of recovery of bacteria from the AMCu surfaces (66.3%) was significantly higher (P < .00001) than the control surfaces (22.4%). The urethane rim common to the stethoscopes was the most heavily burdened surface; mean concentrations exceeded the health care-associated infection acquisition concentration (5 CFU/cm 2 ) by at least 25×, supporting that the stethoscope warrants consideration in plans mitigating microbial cross-transmission during patient care. Stethoscope surfaces fabricated with AMCus were consistently found to harbor fewer bacteria. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  12. Efficient removal of chromate and arsenate from individual and mixed system by malachite nanoparticles.

    PubMed

    Saikia, Jiban; Saha, Bedabrata; Das, Gopal

    2011-02-15

    Malachite nanoparticles of 100-150 nm have been efficiently and for the first time used as an adsorbent for the removal of toxic arsenate and chromate. We report a high adsorption capacity for chromate and arsenate on malachite nanoparticle from both individual and mixed solution in pH ∼4-5. However, the adsorption efficiency decreases with the increase of solution pH. Batch studies revealed that initial pH, temperature, malachite nanoparticles dose and initial concentration of chromate and arsenate were important parameters for the adsorption process. Thermodynamic analysis showed that adsorption of chromate and arsenate on malachite nanoparticles is endothermic and spontaneous. The adsorption of these anions has also been investigated quantitatively with the help of adsorption kinetics, isotherm, and selectivity coefficient (K) analysis. The adsorption data for both chromate and arsenate were fitted well in Langmuir isotherm and preferentially followed the second order kinetics. The binding affinity of chromate is found to be slightly higher than arsenate in a competitive adsorption process which leads to the comparatively higher adsorption of chromate on malachite nanoparticles surface. Copyright © 2010 Elsevier B.V. All rights reserved.

  13. The ACC strategy in biomineralization: the case of earthworm's amorphous spherulites

    NASA Astrophysics Data System (ADS)

    Briones, Maria J. I.; Alvarez-Otero, Rosa; Méndez, Jesús; Gago Duport, Luis

    2010-05-01

    The occurrence of amorphous calcium carbonate (ACC), an hydrated and highly soluble form of solid CaCO3, seems to be a common feature in all carbonate forming organisms such as mollusks, corals, echinoderms and crustaceans. The ubiquity of ACC in these Ca-carbonate biomineralizing systems, as a precursor of further crystalline phases, has recently open the interesting question about if the formation of an amorphous phase is a necessary step in the calcification process of all organisms and consequently, whether it would be possible to define the "amorphous precursor estategy" as a general mechanism in biomineralization. Neverthelees, although ACC appears to be widespread in these organisms very little is known about its particular role in the biomineralization scheme of the different phyla. The formation of CaCO3 spherulites in the calciferous glands of earthworms is a particular case of calcareous biomineralization involving the presence of ACC as a transient precursor phase [2]. Interestingly, the formation of crystalline carbonates via ACC in these organisms is not connected with skeleton building so it must play another functional role. In addition, the transient transformation stages can be followed by in situ spectrometric techniques and therefore, earthworms provide and adequate model to analyse the mutual interactions between ACC-solvent-and crystalline phases. In this study, we have analysed the morphological and structural transformations from the initial ACC spherulites until the formation of the crystalline phases: vaterite (and/or aragonite) and finally calcite, is accomplished. The characterization of ACC was done by performing in situ FT-IR, together with and HREM and Debye scherrer -XRD. The structural results were interpreted in the light of the histological study of the gland. The geometry of the secretory epithelium of the calciferous gland, as evidenced by TEM [2], shows the presence of irregulary shaped cells with their apical surface

  14. Multidepth imaging by chromatic dispersion confocal microscopy

    NASA Astrophysics Data System (ADS)

    Olsovsky, Cory A.; Shelton, Ryan L.; Saldua, Meagan A.; Carrasco-Zevallos, Oscar; Applegate, Brian E.; Maitland, Kristen C.

    2012-03-01

    Confocal microscopy has shown potential as an imaging technique to detect precancer. Imaging cellular features throughout the depth of epithelial tissue may provide useful information for diagnosis. However, the current in vivo axial scanning techniques for confocal microscopy are cumbersome, time-consuming, and restrictive when attempting to reconstruct volumetric images acquired in breathing patients. Chromatic dispersion confocal microscopy (CDCM) exploits severe longitudinal chromatic aberration in the system to axially disperse light from a broadband source and, ultimately, spectrally encode high resolution images along the depth of the object. Hyperchromat lenses are designed to have severe and linear longitudinal chromatic aberration, but have not yet been used in confocal microscopy. We use a hyperchromat lens in a stage scanning confocal microscope to demonstrate the capability to simultaneously capture information at multiple depths without mechanical scanning. A photonic crystal fiber pumped with a 830nm wavelength Ti:Sapphire laser was used as a supercontinuum source, and a spectrometer was used as the detector. The chromatic aberration and magnification in the system give a focal shift of 140μm after the objective lens and an axial resolution of 5.2-7.6μm over the wavelength range from 585nm to 830nm. A 400x400x140μm3 volume of pig cheek epithelium was imaged in a single X-Y scan. Nuclei can be seen at several depths within the epithelium. The capability of this technique to achieve simultaneous high resolution confocal imaging at multiple depths may reduce imaging time and motion artifacts and enable volumetric reconstruction of in vivo confocal images of the epithelium.

  15. Accommodation to Wavefront Vergence and Chromatic Aberration

    PubMed Central

    Wang, Yinan; Kruger, Philip B.; Li, James S.; Lin, Peter L.; Stark, Lawrence R.

    2011-01-01

    Purpose Longitudinal chromatic aberration (LCA) provides a cue to accommodation with small pupils. However, large pupils increase monochromatic aberrations, which may obscure chromatic blur. In the present study, we examined the effect of pupil size and LCA on accommodation. Methods Accommodation was recorded by infrared optometer while observers (nine normal trichromats) viewed a sinusoidally moving Maltese cross target in a Badal stimulus system. There were two illumination conditions: white (3000 K; 20 cd/m2) and monochromatic (550 nm with 10 nm bandwidth; 20 cd/m2) and two artificial pupil conditions (3 mm and 5.7 mm). Separately, static measurements of wavefront aberration were made with the eye accommodating to targets between 0 and 4 D (COAS, Wavefront Sciences). Results Large individual differences in accommodation to wavefront vergence and to LCA are a hallmark of accommodation. LCA continues to provide a signal at large pupil sizes despite higher levels of monochromatic aberrations. Conclusions Monochromatic aberrations may defend against chromatic blur at high spatial frequencies, but accommodation responds best to optical vergence and to LCA at 3 c/deg where blur from higher order aberrations is less. PMID:21317666

  16. Chromatic confocal microscopy for multi-depth imaging of epithelial tissue

    PubMed Central

    Olsovsky, Cory; Shelton, Ryan; Carrasco-Zevallos, Oscar; Applegate, Brian E.; Maitland, Kristen C.

    2013-01-01

    We present a novel chromatic confocal microscope capable of volumetric reflectance imaging of microstructure in non-transparent tissue. Our design takes advantage of the chromatic aberration of aspheric lenses that are otherwise well corrected. Strong chromatic aberration, generated by multiple aspheres, longitudinally disperses supercontinuum light onto the sample. The backscattered light detected with a spectrometer is therefore wavelength encoded and each spectrum corresponds to a line image. This approach obviates the need for traditional axial mechanical scanning techniques that are difficult to implement for endoscopy and susceptible to motion artifact. A wavelength range of 590-775 nm yielded a >150 µm imaging depth with ~3 µm axial resolution. The system was further demonstrated by capturing volumetric images of buccal mucosa. We believe these represent the first microstructural images in non-transparent biological tissue using chromatic confocal microscopy that exhibit long imaging depth while maintaining acceptable resolution for resolving cell morphology. Miniaturization of this optical system could bring enhanced speed and accuracy to endomicroscopic in vivo volumetric imaging of epithelial tissue. PMID:23667789

  17. Impact of Atmospheric Chromatic Effects on Weak Lensing Measurements

    NASA Astrophysics Data System (ADS)

    Meyers, Joshua E.; Burchat, Patricia R.

    2015-07-01

    Current and future imaging surveys will measure cosmic shear with statistical precision that demands a deeper understanding of potential systematic biases in galaxy shape measurements than has been achieved to date. We use analytic and computational techniques to study the impact on shape measurements of two atmospheric chromatic effects for ground-based surveys such as the Dark Energy Survey and the Large Synoptic Survey Telescope (LSST): (1) atmospheric differential chromatic refraction and (2) wavelength dependence of seeing. We investigate the effects of using the point-spread function (PSF) measured with stars to determine the shapes of galaxies that have different spectral energy distributions than the stars. We find that both chromatic effects lead to significant biases in galaxy shape measurements for current and future surveys, if not corrected. Using simulated galaxy images, we find a form of chromatic “model bias” that arises when fitting a galaxy image with a model that has been convolved with a stellar, instead of galactic, PSF. We show that both forms of atmospheric chromatic biases can be predicted (and corrected) with minimal model bias by applying an ordered set of perturbative PSF-level corrections based on machine-learning techniques applied to six-band photometry. Catalog-level corrections do not address the model bias. We conclude that achieving the ultimate precision for weak lensing from current and future ground-based imaging surveys requires a detailed understanding of the wavelength dependence of the PSF from the atmosphere, and from other sources such as optics and sensors. The source code for this analysis is available at https://github.com/DarkEnergyScienceCollaboration/chroma.

  18. Minimal impact of age and housing temperature on the metabolic phenotype of Acc2-/- mice.

    PubMed

    Brandon, Amanda E; Stuart, Ella; Leslie, Simon J; Hoehn, Kyle L; James, David E; Kraegen, Edward W; Turner, Nigel; Cooney, Gregory J

    2016-03-01

    An important regulator of fatty acid oxidation (FAO) is the allosteric inhibition of CPT-1 by malonyl-CoA produced by the enzyme acetyl-CoA carboxylase 2 (ACC2). Initial studies suggested that deletion of Acc2 (Acacb) increased fat oxidation and reduced adipose tissue mass but in an independently generated strain of Acc2 knockout mice we observed increased whole-body and skeletal muscle FAO and a compensatory increase in muscle glycogen stores without changes in glucose tolerance, energy expenditure or fat mass in young mice (12-16 weeks). The aim of the present study was to determine whether there was any effect of age or housing at thermoneutrality (29 °C; which reduces total energy expenditure) on the phenotype of Acc2 knockout mice. At 42-54 weeks of age, male WT and Acc2(-/-) mice had similar body weight, fat mass, muscle triglyceride content and glucose tolerance. Consistent with younger Acc2(-/-) mice, aged Acc2(-/-) mice showed increased whole-body FAO (24 h average respiratory exchange ratio=0.95±0.02 and 0.92±0.02 for WT and Acc2(-/-) mice respectively, P<0.05) and skeletal muscle glycogen content (+60%, P<0.05) without any detectable change in whole-body energy expenditure. Hyperinsulinaemic-euglycaemic clamp studies revealed no difference in insulin action between groups with similar glucose infusion rates and tissue glucose uptake. Housing Acc2(-/-) mice at 29 °C did not alter body composition, glucose tolerance or the effects of fat feeding compared with WT mice. These results confirm that manipulation of Acc2 may alter FAO in mice, but this has little impact on body composition or insulin action. © 2016 Society for Endocrinology.

  19. UHF Signal Processing and Pattern Recognition of Partial Discharge in Gas-Insulated Switchgear Using Chromatic Methodology

    PubMed Central

    Wang, Xiaohua; Li, Xi; Rong, Mingzhe; Xie, Dingli; Ding, Dan; Wang, Zhixiang

    2017-01-01

    The ultra-high frequency (UHF) method is widely used in insulation condition assessment. However, UHF signal processing algorithms are complicated and the size of the result is large, which hinders extracting features and recognizing partial discharge (PD) patterns. This article investigated the chromatic methodology that is novel in PD detection. The principle of chromatic methodologies in color science are introduced. The chromatic processing represents UHF signals sparsely. The UHF signals obtained from PD experiments were processed using chromatic methodology and characterized by three parameters in chromatic space (H, L, and S representing dominant wavelength, signal strength, and saturation, respectively). The features of the UHF signals were studied hierarchically. The results showed that the chromatic parameters were consistent with conventional frequency domain parameters. The global chromatic parameters can be used to distinguish UHF signals acquired by different sensors, and they reveal the propagation properties of the UHF signal in the L-shaped gas-insulated switchgear (GIS). Finally, typical PD defect patterns had been recognized by using novel chromatic parameters in an actual GIS tank and good performance of recognition was achieved. PMID:28106806

  20. UHF Signal Processing and Pattern Recognition of Partial Discharge in Gas-Insulated Switchgear Using Chromatic Methodology.

    PubMed

    Wang, Xiaohua; Li, Xi; Rong, Mingzhe; Xie, Dingli; Ding, Dan; Wang, Zhixiang

    2017-01-18

    The ultra-high frequency (UHF) method is widely used in insulation condition assessment. However, UHF signal processing algorithms are complicated and the size of the result is large, which hinders extracting features and recognizing partial discharge (PD) patterns. This article investigated the chromatic methodology that is novel in PD detection. The principle of chromatic methodologies in color science are introduced. The chromatic processing represents UHF signals sparsely. The UHF signals obtained from PD experiments were processed using chromatic methodology and characterized by three parameters in chromatic space ( H , L , and S representing dominant wavelength, signal strength, and saturation, respectively). The features of the UHF signals were studied hierarchically. The results showed that the chromatic parameters were consistent with conventional frequency domain parameters. The global chromatic parameters can be used to distinguish UHF signals acquired by different sensors, and they reveal the propagation properties of the UHF signal in the L-shaped gas-insulated switchgear (GIS). Finally, typical PD defect patterns had been recognized by using novel chromatic parameters in an actual GIS tank and good performance of recognition was achieved.

  1. Spectrally-balanced chromatic approach-lighting system

    NASA Technical Reports Server (NTRS)

    Chase, W. D.

    1977-01-01

    Approach lighting system employing combinations of red and blue lights reduces problem of color-based optical illusions. System exploits inherent chromatic aberration of eye to create three-dimensional effect, giving pilot visual clues of position.

  2. Skeletal muscle ACC2 S212 phosphorylation is not required for the control of fatty acid oxidation during exercise.

    PubMed

    O'Neill, Hayley M; Lally, James S; Galic, Sandra; Pulinilkunnil, Thomas; Ford, Rebecca J; Dyck, Jason R B; van Denderen, Bryce J; Kemp, Bruce E; Steinberg, Gregory R

    2015-07-01

    During submaximal exercise fatty acids are a predominant energy source for muscle contractions. An important regulator of fatty acid oxidation is acetyl-CoA carboxylase (ACC), which exists as two isoforms (ACC1 and ACC2) with ACC2 predominating in skeletal muscle. Both ACC isoforms regulate malonyl-CoA production, an allosteric inhibitor of carnitine palmitoyltransferase 1 (CPT-1); the primary enzyme controlling fatty acyl-CoA flux into mitochondria for oxidation. AMP-activated protein kinase (AMPK) is a sensor of cellular energy status that is activated during exercise or by pharmacological agents such as metformin and AICAR. In resting muscle the activation of AMPK with AICAR leads to increased phosphorylation of ACC (S79 on ACC1 and S221 on ACC2), which reduces ACC activity and malonyl-CoA; effects associated with increased fatty acid oxidation. However, whether this pathway is vital for regulating skeletal muscle fatty acid oxidation during conditions of increased metabolic flux such as exercise/muscle contractions remains unknown. To examine this we characterized mice lacking AMPK phosphorylation sites on ACC2 (S212 in mice/S221 in humans-ACC2-knock-in [ACC2-KI]) or both ACC1 (S79) and ACC2 (S212) (ACC double knock-in [ACCD-KI]) during submaximal treadmill exercise and/or ex vivo muscle contractions. We find that surprisingly, ACC2-KI mice had normal exercise capacity and whole-body fatty acid oxidation during treadmill running despite elevated muscle ACC2 activity and malonyl-CoA. Similar results were observed in ACCD-KI mice. Fatty acid oxidation was also maintained in muscles from ACC2-KI mice contracted ex vivo. These findings indicate that pathways independent of ACC phosphorylation are important for regulating skeletal muscle fatty acid oxidation during exercise/muscle contractions. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  3. Achromatic-chromatic colorimetric sensors for on-off type detection of analytes.

    PubMed

    Heo, Jun Hyuk; Cho, Hui Hun; Lee, Jin Woong; Lee, Jung Heon

    2014-12-21

    We report the development of achromatic colorimetric sensors; sensors changing their colors from achromatic black to other chromatic colors. An achromatic colorimetric sensor was prepared by mixing a general colorimetric indicator, whose color changes between chromatic colors, and a complementary colored dye with no reaction to the targeted analyte. As the color of an achromatic colorimetric sensor changes from black to a chromatic color, the color change could be much easily recognized than general colorimetric sensors with naked eyes. More importantly, the achromatic colorimetric sensors enable on-off type recognition of the presence of analytes, which have not been achieved from most colorimetric sensors. In addition, the color changes from some achromatic colorimetric sensors (achromatic Eriochrome Black T and achromatic Benedict's solution) could be recognized with naked eyes at much lower concentration ranges than normal chromatic colorimetric sensors. These results provide new opportunities in the use of colorimetric sensors for diverse applications, such as harsh industrial, environmental, and biological detection.

  4. ACC Study Guide Series (Revised Edition).

    ERIC Educational Resources Information Center

    Staples, Katherine; And Others

    Designed for the beginning college student who needs to search for information, prepare written assignments, or take tests, the ACC (Austin Community College) Study Guide Series comprises 17 one-page study guides. Printed on card stock with colored headings, the guides are highlighted with cartoon illustrations and are intended to provide…

  5. Triggerfish uses chromaticity and lightness for object segregation

    PubMed Central

    2017-01-01

    Humans group components of visual patterns according to their colour, and perceive colours separately from shape. This property of human visual perception is the basis behind the Ishihara test for colour deficiency, where an observer is asked to detect a pattern made up of dots of similar colour with variable lightness against a background of dots made from different colour(s) and lightness. To find out if fish use colour for object segregation in a similar manner to humans, we used stimuli inspired by the Ishihara test. Triggerfish (Rhinecanthus aculeatus) were trained to detect a cross constructed from similarly coloured dots against various backgrounds. Fish detected this cross even when it was camouflaged using either achromatic or chromatic noise, but fish relied more on chromatic cues for shape segregation. It remains unknown whether fish may switch to rely primarily on achromatic cues in scenarios where target objects have higher achromatic contrast and lower chromatic contrast. Fish were also able to generalize between stimuli of different colours, suggesting that colour and shape are processed by fish independently. PMID:29308267

  6. A simple handheld pupillometer for chromatic Flicker studies

    NASA Astrophysics Data System (ADS)

    Bernabei, M.; Tinarelli, R.; Peretto, L.; Rovati, L.

    2014-02-01

    A portable pupillometer has been developed which is capable of performing accurate measurements of the pupil diameter during chromatic flicker stimulations. The handheld measuring system records the near-infrared image of the pupil at the rate of 25 fps and simultaneously stimulates the eye using a diffused flicker light generated by light emitting diodes (LEDs). Intensity, frequency and chromatic coordinates of the stimulus can be easily adjusted using a user-friendly graphical interface. Thanks to a chromatic monitoring of the stimulus close to the plane of the eye, photopically matched conditions can be easily achieved. The pupil diameter/area can be measured during flickering stimuli that are generated with frequency in a range of 0.1-20 Hz. The electronic unit, properly connected to the personal computer through a USB port, drives the optical unit, which can be easily held in a hand. The software interface controlling the system was developed in LabVIEW. This paper describes the instrument optical setup, front-end electronics and data processing. Moreover preliminary results obtained on a voluntary are reported.

  7. Chromaticity of color perception and object color knowledge.

    PubMed

    Hsu, Nina S; Frankland, Steven M; Thompson-Schill, Sharon L

    2012-01-01

    Sensorimotor theories of semantic memory require overlap between conceptual and perceptual representations. One source of evidence for such overlap comes from neuroimaging reports of co-activation during memory retrieval and perception; for example, regions involved in color perception (i.e., regions that respond more to colored than grayscale stimuli) are activated by retrieval of object color. One unanswered question from these studies is whether distinctions that are observed during perception are likewise observed during memory retrieval. That is, are regions defined by a chromaticity effect in perception similarly modulated by the chromaticity of remembered objects (e.g., lemons more than coal)? Subjects performed color perception and color retrieval tasks while undergoing fMRI. We observed increased activation during both perception and memory retrieval of chromatic compared to achromatic stimuli in overlapping areas of the left lingual gyrus, but not in dorsal or anterior regions activated during color perception. These results support sensorimotor theories but suggest important distinctions within the conceptual system. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. 24 CFR 884.105 - Maximum total ACC commitment and project account (private-owner/PHA projects).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Maximum total ACC commitment and..., Scope and Basic Policies § 884.105 Maximum total ACC commitment and project account (private-owner/PHA projects). (a) Maximum total ACC commitment. The maximum total annual contribution that may be contracted...

  9. 24 CFR 884.105 - Maximum total ACC commitment and project account (private-owner/PHA projects).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Maximum total ACC commitment and..., Scope and Basic Policies § 884.105 Maximum total ACC commitment and project account (private-owner/PHA projects). (a) Maximum total ACC commitment. The maximum total annual contribution that may be contracted...

  10. Extradural Spinal Metastasis of Adenoid Cystic Carcinoma (ACC): A Case Report

    PubMed Central

    Nair, Rajesh; Upadhyaya, Sunil; Nayal, Bhavna; Shetty, Arjun

    2015-01-01

    Adenoid cystic carcinoma (ACC) is a rare malignant tumour of the major salivary glands. It accounts for 10-15% of all salivary gland tumours and 1% of all head and neck tumours. Surgical resection followed by radiation is the choice of treatment for ACC. However, late loco-regional recurrence and metastasis is often seen emphasizing the importance of long-term follow-up. We report an unusual case of extradural metastasis of ACC in the dorsal spine. The primary submandibular gland tumour was resected 11 y back. A recurrence had been detected two years prior to the occurrence of spinal metastasis. Surgical decompression was done which was followed by palliative radiotherapy. Patient is symptomatically better, ambulant and on regular follow-up. PMID:25738073

  11. On the r-dynamic chromatic number of the corronation by complete graph

    NASA Astrophysics Data System (ADS)

    Indah Kristiana, Arika; Imam Utoyo, M.; Dafik

    2018-04-01

    In this paper we will study the r-dynamic chromatic number of the coronation by complete graph. A proper k-coloring of graph G such that the neighbors of any vertex v receive at least min{r, d(v)} different colors. The r-dynamic chromatic number, χ r (G) is the minimum k such that graph G has an r-dynamic k-coloring. We will obtain lower bound of the r-dynamic chromatic number of {χ }r({K}nȯ H), and {χ }r(Hȯ {K}m) We also study the exact value of the r-dynamic chromatic number of {χ }r({K}nȯ {S}m),{χ }r({K}nȯ {F}m),{χ }r({S}nȯ {K}m),{χ }r({F}nȯ {K}m) and {χ }r({K}nȯ {K}m) for m, n > 3.

  12. Accurate and fiducial-marker-free correction for three-dimensional chromatic shift in biological fluorescence microscopy.

    PubMed

    Matsuda, Atsushi; Schermelleh, Lothar; Hirano, Yasuhiro; Haraguchi, Tokuko; Hiraoka, Yasushi

    2018-05-15

    Correction of chromatic shift is necessary for precise registration of multicolor fluorescence images of biological specimens. New emerging technologies in fluorescence microscopy with increasing spatial resolution and penetration depth have prompted the need for more accurate methods to correct chromatic aberration. However, the amount of chromatic shift of the region of interest in biological samples often deviates from the theoretical prediction because of unknown dispersion in the biological samples. To measure and correct chromatic shift in biological samples, we developed a quadrisection phase correlation approach to computationally calculate translation, rotation, and magnification from reference images. Furthermore, to account for local chromatic shifts, images are split into smaller elements, for which the phase correlation between channels is measured individually and corrected accordingly. We implemented this method in an easy-to-use open-source software package, called Chromagnon, that is able to correct shifts with a 3D accuracy of approximately 15 nm. Applying this software, we quantified the level of uncertainty in chromatic shift correction, depending on the imaging modality used, and for different existing calibration methods, along with the proposed one. Finally, we provide guidelines to choose the optimal chromatic shift registration method for any given situation.

  13. Separating monocular and binocular neural mechanisms mediating chromatic contextual interactions.

    PubMed

    D'Antona, Anthony D; Christiansen, Jens H; Shevell, Steven K

    2014-04-17

    When seen in isolation, a light that varies in chromaticity over time is perceived to oscillate in color. Perception of that same time-varying light may be altered by a surrounding light that is also temporally varying in chromaticity. The neural mechanisms that mediate these contextual interactions are the focus of this article. Observers viewed a central test stimulus that varied in chromaticity over time within a larger surround that also varied in chromaticity at the same temporal frequency. Center and surround were presented either to the same eye (monocular condition) or to opposite eyes (dichoptic condition) at the same frequency (3.125, 6.25, or 9.375 Hz). Relative phase between center and surround modulation was varied. In both the monocular and dichoptic conditions, the perceived modulation depth of the central light depended on the relative phase of the surround. A simple model implementing a linear combination of center and surround modulation fit the measurements well. At the lowest temporal frequency (3.125 Hz), the surround's influence was virtually identical for monocular and dichoptic conditions, suggesting that at this frequency, the surround's influence is mediated primarily by a binocular neural mechanism. At higher frequencies, the surround's influence was greater for the monocular condition than for the dichoptic condition, and this difference increased with temporal frequency. Our findings show that two separate neural mechanisms mediate chromatic contextual interactions: one binocular and dominant at lower temporal frequencies and the other monocular and dominant at higher frequencies (6-10 Hz).

  14. Psychophysical and physiological responses to gratings with luminance and chromatic components of different spatial frequencies.

    PubMed

    Cooper, Bonnie; Sun, Hao; Lee, Barry B

    2012-02-01

    Gratings that contain luminance and chromatic components of different spatial frequencies were used to study the segregation of signals in luminance and chromatic pathways. Psychophysical detection and discrimination thresholds to these compound gratings, with luminance and chromatic components of the one either half or double the spatial frequency of the other, were measured in human observers. Spatial frequency tuning curves for detection of compound gratings followed the envelope of those for luminance and chromatic gratings. Different grating types were discriminable at detection threshold. Fourier analysis of physiological responses of macaque retinal ganglion cells to compound waveforms showed chromatic information to be restricted to the parvocellular pathway and luminance information to the magnocellular pathway. Taken together, the human psychophysical and macaque physiological data support the strict segregation of luminance and chromatic information in independent channels, with the magnocellular and parvocellular pathways, respectively, serving as likely the physiological substrates. © 2012 Optical Society of America

  15. Uncertainty of chromatic dispersion estimation from transmitted waveforms in direct detection systems

    NASA Astrophysics Data System (ADS)

    Lach, Zbigniew T.

    2017-08-01

    A possibility is shown of a non-disruptive estimation of chromatic dispersion in a fiber of an intensity modulation communication line under work conditions. Uncertainty of the chromatic dispersion estimates is analyzed and quantified with the use of confidence intervals.

  16. Cloning and sequence analysis demonstrate the chromate reduction ability of a novel chromate reductase gene from Serratia sp.

    PubMed

    Deng, Peng; Tan, Xiaoqing; Wu, Ying; Bai, Qunhua; Jia, Yan; Xiao, Hong

    2015-03-01

    The ChrT gene encodes a chromate reductase enzyme which catalyzes the reduction of Cr(VI). The chromate reductase is also known as flavin mononucleotide (FMN) reductase (FMN_red). The aim of the present study was to clone the full-length ChrT DNA from Serratia sp. CQMUS2 and analyze the deduced amino acid sequence and three-dimensional structure. The putative ChrT gene fragment of Serratia sp. CQMUS2 was isolated by polymerase chain reaction (PCR), according to the known FMN_red gene sequence from Serratia sp. AS13. The flanking sequences of the ChrT gene were obtained by high efficiency TAIL-PCR, while the full-length gene of ChrT was cloned in Escherichia coli for subsequent sequencing. The nucleotide sequence of ChrT was submitted onto GenBank under the accession number, KF211434. Sequence analysis of the gene and amino acids was conducted using the Basic Local Alignment Search Tool, and open reading frame (ORF) analysis was performed using ORF Finder software. The ChrT gene was found to be an ORF of 567 bp that encodes a 188-amino acid enzyme with a calculated molecular weight of 20.4 kDa. In addition, the ChrT protein was hypothesized to be an NADPH-dependent FMN_red and a member of the flavodoxin-2 superfamily. The amino acid sequence of ChrT showed high sequence similarity to the FMN reductase genes of Klebsiella pneumonia and Raoultella ornithinolytica , which belong to the flavodoxin-2 superfamily. Furthermore, ChrT was shown to have a 85.6% similarity to the three-dimensional structure of Escherichia coli ChrR, sharing four common enzyme active sites for chromate reduction. Therefore, ChrT gene cloning and protein structure determination demonstrated the ability of the gene for chromate reduction. The results of the present study provide a basis for further studies on ChrT gene expression and protein function.

  17. Cloning and sequence analysis demonstrate the chromate reduction ability of a novel chromate reductase gene from Serratia sp

    PubMed Central

    DENG, PENG; TAN, XIAOQING; WU, YING; BAI, QUNHUA; JIA, YAN; XIAO, HONG

    2015-01-01

    The ChrT gene encodes a chromate reductase enzyme which catalyzes the reduction of Cr(VI). The chromate reductase is also known as flavin mononucleotide (FMN) reductase (FMN_red). The aim of the present study was to clone the full-length ChrT DNA from Serratia sp. CQMUS2 and analyze the deduced amino acid sequence and three-dimensional structure. The putative ChrT gene fragment of Serratia sp. CQMUS2 was isolated by polymerase chain reaction (PCR), according to the known FMN_red gene sequence from Serratia sp. AS13. The flanking sequences of the ChrT gene were obtained by high efficiency TAIL-PCR, while the full-length gene of ChrT was cloned in Escherichia coli for subsequent sequencing. The nucleotide sequence of ChrT was submitted onto GenBank under the accession number, KF211434. Sequence analysis of the gene and amino acids was conducted using the Basic Local Alignment Search Tool, and open reading frame (ORF) analysis was performed using ORF Finder software. The ChrT gene was found to be an ORF of 567 bp that encodes a 188-amino acid enzyme with a calculated molecular weight of 20.4 kDa. In addition, the ChrT protein was hypothesized to be an NADPH-dependent FMN_red and a member of the flavodoxin-2 superfamily. The amino acid sequence of ChrT showed high sequence similarity to the FMN reductase genes of Klebsiella pneumonia and Raoultella ornithinolytica, which belong to the flavodoxin-2 superfamily. Furthermore, ChrT was shown to have a 85.6% similarity to the three-dimensional structure of Escherichia coli ChrR, sharing four common enzyme active sites for chromate reduction. Therefore, ChrT gene cloning and protein structure determination demonstrated the ability of the gene for chromate reduction. The results of the present study provide a basis for further studies on ChrT gene expression and protein function. PMID:25667630

  18. Efficient estimation and large-scale evaluation of lateral chromatic aberration for digital image forensics

    NASA Astrophysics Data System (ADS)

    Gloe, Thomas; Borowka, Karsten; Winkler, Antje

    2010-01-01

    The analysis of lateral chromatic aberration forms another ingredient for a well equipped toolbox of an image forensic investigator. Previous work proposed its application to forgery detection1 and image source identification.2 This paper takes a closer look on the current state-of-the-art method to analyse lateral chromatic aberration and presents a new approach to estimate lateral chromatic aberration in a runtime-efficient way. Employing a set of 11 different camera models including 43 devices, the characteristic of lateral chromatic aberration is investigated in a large-scale. The reported results point to general difficulties that have to be considered in real world investigations.

  19. Measurement and correction of transverse chromatic offsets for multi-wavelength retinal microscopy in the living eye.

    PubMed

    Harmening, Wolf M; Tiruveedhula, Pavan; Roorda, Austin; Sincich, Lawrence C

    2012-09-01

    A special challenge arises when pursuing multi-wavelength imaging of retinal tissue in vivo, because the eye's optics must be used as the main focusing elements, and they introduce significant chromatic dispersion. Here we present an image-based method to measure and correct for the eye's transverse chromatic aberrations rapidly, non-invasively, and with high precision. We validate the technique against hyperacute psychophysical performance and the standard chromatic human eye model. In vivo correction of chromatic dispersion will enable confocal multi-wavelength images of the living retina to be aligned, and allow targeted chromatic stimulation of the photoreceptor mosaic to be performed accurately with sub-cellular resolution.

  20. Measurement and correction of transverse chromatic offsets for multi-wavelength retinal microscopy in the living eye

    PubMed Central

    Harmening, Wolf M.; Tiruveedhula, Pavan; Roorda, Austin; Sincich, Lawrence C.

    2012-01-01

    A special challenge arises when pursuing multi-wavelength imaging of retinal tissue in vivo, because the eye’s optics must be used as the main focusing elements, and they introduce significant chromatic dispersion. Here we present an image-based method to measure and correct for the eye’s transverse chromatic aberrations rapidly, non-invasively, and with high precision. We validate the technique against hyperacute psychophysical performance and the standard chromatic human eye model. In vivo correction of chromatic dispersion will enable confocal multi-wavelength images of the living retina to be aligned, and allow targeted chromatic stimulation of the photoreceptor mosaic to be performed accurately with sub-cellular resolution. PMID:23024901

  1. The effects of luminance contribution from large fields to chromatic visual evoked potentials.

    PubMed

    Skiba, Rafal M; Duncan, Chad S; Crognale, Michael A

    2014-02-01

    Though useful from a clinical and practical standpoint uniform, large-field chromatic stimuli are likely to contain luminance contributions from retinal inhomogeneities. Such contribution can significantly influence psychophysical thresholds. However, the degree to which small luminance artifacts influence the chromatic VEP has been debated. In particular, claims have been made that band-pass tuning observed in chromatic VEPs result from luminance intrusion. However, there has been no direct evidence presented to support these claims. Recently, large-field isoluminant stimuli have been developed to control for intrusion from retinal inhomogeneities with particular regard to the influence of macular pigment. We report here the application of an improved version of these full-field stimuli to directly test the influence of luminance intrusion on the temporal tuning of the chromatic VEP. Our results show that band-pass tuning persists even when isoluminance is achieved throughout the extent of the stimulus. In addition, small amounts of luminance intrusion affect neither the shape of the temporal tuning function nor the major components of the VEP. These results support the conclusion that the chromatic VEP can depart substantially from threshold psychophysics with regard to temporal tuning and that obtaining a low-pass function is not requisite evidence of selective chromatic activation in the VEP. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Study of Chromatic parameters of Line, Total, Middle graphs and Graph operators of Bipartite graph

    NASA Astrophysics Data System (ADS)

    Nagarathinam, R.; Parvathi, N.

    2018-04-01

    Chromatic parameters have been explored on the basis of graph coloring process in which a couple of adjacent nodes receives different colors. But the Grundy and b-coloring executes maximum colors under certain restrictions. In this paper, Chromatic, b-chromatic and Grundy number of some graph operators of bipartite graph has been investigat

  3. Identification of polymer stabilized blue-phase liquid crystal display by chromaticity diagram

    NASA Astrophysics Data System (ADS)

    Lan, Yi-Fen; Tsai, Cheng-Yeh; Wang, Ling-Yung; Ku, Po-Jen; Huang, Tai-Hsiang; Liu, Chu-Yu; Sugiura, Norio

    2012-04-01

    We reported an identification method of blue phase liquid crystal (BPLC) display status by using Commission International de l'Éclairage (CIE) chromaticity diagram. The BPLC was injected into in-plane-switch (IPS) cell, polymer stabilized (PS) by ultraviolet cured process and analyzed by luminance colorimeter. The results of CIE chromaticity diagram showed a remarkable turning point when polymer stabilized blue phase liquid crystal II (PSBPLC-II) formed in the IPS cell. A mechanism of CIE chromaticity diagram identify PSBPLC display status was proposed, and we believe this finding will be useful to application and production of PSBPLC display.

  4. OpenACC performance for simulating 2D radial dambreak using FVM HLLE flux

    NASA Astrophysics Data System (ADS)

    Gunawan, P. H.; Pahlevi, M. R.

    2018-03-01

    The aim of this paper is to investigate the performances of openACC platform for computing 2D radial dambreak. Here, the shallow water equation will be used to describe and simulate 2D radial dambreak with finite volume method (FVM) using HLLE flux. OpenACC is a parallel computing platform based on GPU cores. Indeed, from this research this platform is used to minimize computational time on the numerical scheme performance. The results show the using OpenACC, the computational time is reduced. For the dry and wet radial dambreak simulations using 2048 grids, the computational time of parallel is obtained 575.984 s and 584.830 s respectively for both simulations. These results show the successful of OpenACC when they are compared with the serial time of dry and wet radial dambreak simulations which are collected 28047.500 s and 29269.40 s respectively.

  5. Zinc Chromate Induces Chromosome Instability and DNA Double Strand Breaks in Human Lung Cells

    PubMed Central

    Xie, Hong; Holmes, Amie L.; Young, Jamie L.; Qin, Qin; Joyce, Kellie; Pelsue, Stephen C.; Peng, Cheng; Wise, Sandra S.; Jeevarajan, Antony S.; Wallace, William T.; Hammond, Dianne; Wise, John Pierce

    2014-01-01

    Hexavalent chromium Cr(VI) is a respiratory toxicant and carcinogen, with solubility playing an important role in its carcinogenic potential. Zinc chromate, a water insoluble or ‘particulate’ Cr(VI) compound, has been shown to be carcinogenic in epidemiology studies and to induce tumors in experimental animals, but its genotoxicity is poorly understood. Our study shows that zinc chromate induced concentration-dependent increases in cytotoxicity, chromosome damage and DNA double strand breaks in human lung cells. In response to zinc chromate-induced breaks, MRE11 expression was increased and ATM and ATR were phosphorylated, indicating that the DNA double strand break repair system was initiated in the cells. In addition, our data show that zinc chromate-induced double strand breaks were only observed in the G2/M phase population, with no significant amount of double strand breaks observed in G1 and S phase cells. These data will aid in understanding the mechanisms of zinc chromate toxicity and carcinogenesis. PMID:19027772

  6. Visual reaction time for chromaticity changes at constant luminance in different color representation systems

    NASA Astrophysics Data System (ADS)

    Jimenezdel Barco, L.; Jimenez, J. R.; Rubino, M.; Diaz, J. A.

    1996-09-01

    The results obtained by different authors show that when a color stimulus changes in both luminance and chromaticity, the visual reaction time (VRT) of an observer in detecting this chromatic change depends on nothing more than the luminance change and is regulated by Pieron's law. In the present work, we evaluate the VRT needed by an observer to detect the chromaticity difference between an adapting and variable stimulus. For this, we have used the experimental method of hue substitution, which allows us to maintain the luminance channel constant and thereby study the temporal response to changes only in chromaticity. The experiments were carried out with a CRT color monitor and the experimental results are expressed in different color-representation systems. The systems UCS-CIE 1964 (U*, V*, W*) and CIELUV show good correlations between the VRT and the chromaticity difference expressed in these systems, adjusting the VRT to an expression following Pieron's law: VRT-VRTon=k( Delta E)- beta .

  7. V1 mechanisms underlying chromatic contrast detection

    PubMed Central

    Hass, Charles A.

    2013-01-01

    To elucidate the cortical mechanisms of color vision, we recorded from individual primary visual cortex (V1) neurons in macaque monkeys performing a chromatic detection task. Roughly 30% of the neurons that we encountered were unresponsive at the monkeys' psychophysical detection threshold (PT). The other 70% were responsive at threshold but on average, were slightly less sensitive than the monkey. For these neurons, the relationship between neurometric threshold (NT) and PT was consistent across the four isoluminant color directions tested. A corollary of this result is that NTs were roughly four times lower for stimuli that modulated the long- and middle-wavelength sensitive cones out of phase. Nearly one-half of the neurons that responded to chromatic stimuli at the monkeys' detection threshold also responded to high-contrast luminance modulations, suggesting a role for neurons that are jointly tuned to color and luminance in chromatic detection. Analysis of neuronal contrast-response functions and signal-to-noise ratios yielded no evidence for a special set of “cardinal color directions,” for which V1 neurons are particularly sensitive. We conclude that at detection threshold—as shown previously with high-contrast stimuli—V1 neurons are tuned for a diverse set of color directions and do not segregate naturally into red–green and blue–yellow categories. PMID:23446689

  8. Chronic Exposure to Zinc Chromate Induces Centrosome Amplification and Spindle Assembly Checkpoint Bypass in Human Lung Fibroblasts

    PubMed Central

    Holmes, Amie L.; Wise, Sandra S.; Pelsue, Stephen C.; Aboueissa, AbouEl-Makarim; Lingle, Wilma; Salisbury, Jeffery; Gallagher, Jamie; Wise, John Pierce

    2010-01-01

    Hexavalent chromium (Cr(VI)) compounds are known human lung carcinogens. Solubility plays an important role in its carcinogenicity with the particulate or insoluble form being the most potent. Of the particulate Cr(VI) compounds, zinc chromate appears to be the most potent carcinogen, however, very few studies have investigated its carcinogenic mechanism. In this study, we investigated the ability of chronic exposure to zinc chromate to induce numerical chromosome instability. We found no increase in aneuploidy after a 24 hour exposure to zinc chromate, but with more chronic exposures, zinc chromate induced concentration- and time-dependent increases in aneuploidy in the form of hypodiploidy, hyperdiploidy and tetraploidy. Zinc chromate also induced centrosome amplification in a concentration- and time-dependent manner in both interphase and mitotic cells after chronic exposure, producing cells with centriolar defects. Further, chronic exposure to zinc chromate induced concentration- and time-dependent increases in spindle assembly checkpoint bypass with increases in centromere spreading, premature centromere division and premature anaphase. Lastly, we found that chronic exposure to zinc chromate induced a G2 arrest. All together, these data indicate that zinc chromate can induce chromosome instability after prolonged exposures. PMID:20030412

  9. Further studies of auxin and ACC induced feminization in the cucumber plant using ethylene inhibitors

    NASA Technical Reports Server (NTRS)

    Takahashi, H.; Jaffe, M. J.

    1984-01-01

    The present study was designed to establish the role of an essential hormone controlling sex expression in cucumber. A potent anti-ethylene agent, AgNO3, completely inhibited pistillate flower formation caused by IAA, ACC or ethephon. Inhibitors of ethylene biosynthesis, AVG and CoCl2 also suppressed feminization due to exogenous IAA or ACC. Though AVG also suppressed ethephon-induced feminization, this may be due to the second effect of AVG rather than the effect on ACC biosynthesis. These results confirm that ethylene is a major factor regulating feminization and that exogenous auxin induces pistillate flower formation through its stimulation of ethylene production, rather than ACC production.

  10. Reduced heart size and increased myocardial fuel substrate oxidation in ACC2 mutant mice

    PubMed Central

    Essop, M. Faadiel; Camp, Heidi S.; Choi, Cheol Soo; Sharma, Saumya; Fryer, Ryan M.; Reinhart, Glenn A.; Guthrie, Patrick H.; Bentebibel, Assia; Gu, Zeiwei; Shulman, Gerald I.; Taegtmeyer, Heinrich; Wakil, Salih J.; Abu-Elheiga, Lutfi

    2008-01-01

    The cardiac-enriched isoform of acetyl-CoA carboxylase (ACC2) is a key regulator of mitochondrial fatty acid (FA) uptake via carnitine palmitoyltransferase 1 (CPT1). To test the hypothesis that oxidative metabolism is upregulated in hearts from animals lacking ACC2 (employing a transgenic Acc2-mutant mouse), we assessed cardiac function in vivo and determined rates of myocardial substrate oxidation ex vivo. When examined by echocardiography, there was no difference in systolic function, but left ventricular mass of the Acc2-mutant (MUT) mouse was significantly reduced (∼25%) compared with wild-types (WT). Reduced activation of the mammalian target of rapamycin (mTOR) and its downstream target p70S6K was found in MUT hearts. Exogenous oxidation rates of oleate were increased ∼22%, and, unexpectedly, exogenous glucose oxidation rates were also increased in MUT hearts. Using a hyperinsulinemic-euglycemic clamp, we found that glucose uptake in MUT hearts was increased by ∼83%. Myocardial triglyceride levels were significantly reduced in MUT vs. WT while glycogen content was the same. In parallel, transcript levels of PPARα and its target genes, pyruvate dehydrogenase kinase-4 (PDK-4), malonyl-CoA decarboxylase (MCD), and mCPT1, were downregulated in MUT mice. In summary, we report that 1) Acc2-mutant hearts exhibit a marked preference for the oxidation of both glucose and FAs coupled with greater utilization of endogenous fuel substrates (triglycerides), 2) attenuated mTOR signaling may result in reduced heart sizes observed in Acc2-mutant mice, and 3) Acc2-mutant hearts displayed normal functional parameters despite a significant decrease in size. PMID:18487439

  11. Variation in Extracellular Detoxification Is a Link to Different Carcinogenicity among Chromates in Rodent and Human Lungs.

    PubMed

    Krawic, Casey; Luczak, Michal W; Zhitkovich, Anatoly

    2017-09-18

    Inhalation of soluble chromium(VI) is firmly linked with higher risks of lung cancer in humans. However, comparative studies in rats have found a high lung tumorigenicity for moderately soluble chromates but no tumors for highly soluble chromates. These major species differences remain unexplained. We investigated the impact of extracellular reducers on responses of human and rat lung epithelial cells to different Cr(VI) forms. Extracellular reduction of Cr(VI) is a detoxification process, and rat and human lung lining fluids contain different concentrations of ascorbate and glutathione. We found that reduction of chromate anions in simulated lung fluids was principally driven by ascorbate with only minimal contribution from glutathione. The addition of 500 μM ascorbate (∼rat lung fluid concentration) to culture media strongly inhibited cellular uptake of chromate anions and completely prevented their cytotoxicity even at otherwise lethal doses. While proportionally less effective, 50 μM extracellular ascorbate (∼human lung fluid concentration) also decreased uptake of chromate anions and their cytotoxicity. In comparison to chromate anions, uptake and cytotoxicity of respirable particles of moderately soluble CaCrO 4 and SrCrO 4 were much less sensitive to suppression by extracellular ascorbate, especially during early exposure times and in primary bronchial cells. In the absence of extracellular ascorbate, chromate anions and CaCrO 4 /SrCrO 4 particles produced overall similar levels of DNA double-stranded breaks, with less soluble particles exhibiting a slower rate of breakage. Our results indicate that a gradual extracellular dissolution and a rapid internalization of calcium chromate and strontium chromate particles makes them resistant to detoxification outside the cells, which is extremely effective for chromate anions in the rat lung fluid. The detoxification potential of the human lung fluid is significant but much lower and insufficient to provide a

  12. Chromatic aberrations correction for imaging spectrometer based on acousto-optic tunable filter with two transducers.

    PubMed

    Zhao, Huijie; Wang, Ziye; Jia, Guorui; Zhang, Ying; Xu, Zefu

    2017-10-02

    The acousto-optic tunable filter (AOTF) with wide wavelength range and high spectral resolution has long crystal and two transducers. A longer crystal length leads to a bigger chromatic focal shift and the double-transducer arrangement induces angular mutation in diffracted beam, which increase difficulty in longitudinal and lateral chromatic aberration correction respectively. In this study, the two chromatic aberrations are analyzed quantitatively based on an AOTF optical model and a novel catadioptric dual-path configuration is proposed to correct both the chromatic aberrations. The test results exhibit effectiveness of the optical configuration for this type of AOTF-based imaging spectrometer.

  13. Accumulation and Transport of 1-Aminocyclopropane-1-Carboxylic Acid (ACC) in Plants: Current Status, Considerations for Future Research and Agronomic Applications

    PubMed Central

    Vanderstraeten, Lisa; Van Der Straeten, Dominique

    2017-01-01

    1-aminocyclopropane-1-carboxylic acid (ACC) is a non-protein amino acid acting as the direct precursor of ethylene, a plant hormone regulating a wide variety of vegetative and developmental processes. ACC is the central molecule of ethylene biosynthesis. The rate of ACC formation differs in response to developmental, hormonal and environmental cues. ACC can be conjugated to three derivatives, metabolized in planta or by rhizobacteria using ACC deaminase, and is transported throughout the plant over short and long distances, remotely leading to ethylene responses. This review highlights some recent advances related to ACC. These include the regulation of ACC synthesis, conjugation and deamination, evidence for a role of ACC as an ethylene-independent signal, short and long range ACC transport, and the identification of a first ACC transporter. Although unraveling the complex mechanism of ACC transport is in its infancy, new questions emerge together with the identification of a first transporter. In the light of the future quest for additional ACC transporters, this review presents perspectives of the novel findings and includes considerations for future research toward applications in agronomy. PMID:28174583

  14. Accumulation and Transport of 1-Aminocyclopropane-1-Carboxylic Acid (ACC) in Plants: Current Status, Considerations for Future Research and Agronomic Applications.

    PubMed

    Vanderstraeten, Lisa; Van Der Straeten, Dominique

    2017-01-01

    1-aminocyclopropane-1-carboxylic acid (ACC) is a non-protein amino acid acting as the direct precursor of ethylene, a plant hormone regulating a wide variety of vegetative and developmental processes. ACC is the central molecule of ethylene biosynthesis. The rate of ACC formation differs in response to developmental, hormonal and environmental cues. ACC can be conjugated to three derivatives, metabolized in planta or by rhizobacteria using ACC deaminase, and is transported throughout the plant over short and long distances, remotely leading to ethylene responses. This review highlights some recent advances related to ACC. These include the regulation of ACC synthesis, conjugation and deamination, evidence for a role of ACC as an ethylene-independent signal, short and long range ACC transport, and the identification of a first ACC transporter. Although unraveling the complex mechanism of ACC transport is in its infancy, new questions emerge together with the identification of a first transporter. In the light of the future quest for additional ACC transporters, this review presents perspectives of the novel findings and includes considerations for future research toward applications in agronomy.

  15. Newborns' Discrimination of Chromatic from Achromatic Stimuli.

    ERIC Educational Resources Information Center

    Adams, Russell J.; And Others

    1986-01-01

    Two experiments assessed the extent of newborns' ability to discriminate color. Results imply that newborns have some, albeit limited, capacity to discriminate chromatic from achromatic stimuli, and hence, are at least dichromats. (Author/DR)

  16. Chromatic aberration correction: an enhancement to the calibration of low-cost digital dermoscopes.

    PubMed

    Wighton, Paul; Lee, Tim K; Lui, Harvey; McLean, David; Atkins, M Stella

    2011-08-01

    We present a method for calibrating low-cost digital dermoscopes that corrects for color and inconsistent lighting and also corrects for chromatic aberration. Chromatic aberration is a form of radial distortion that often occurs in inexpensive digital dermoscopes and creates red and blue halo-like effects on edges. Being radial in nature, distortions due to chromatic aberration are not constant across the image, but rather vary in both magnitude and direction. As a result, distortions are not only visually distracting but could also mislead automated characterization techniques. Two low-cost dermoscopes, based on different consumer-grade cameras, were tested. Color is corrected by imaging a reference and applying singular value decomposition to determine the transformation required to ensure accurate color reproduction. Lighting is corrected by imaging a uniform surface and creating lighting correction maps. Chromatic aberration is corrected using a second-order radial distortion model. Our results for color and lighting calibration are consistent with previously published results, while distortions due to chromatic aberration can be reduced by 42-47% in the two systems considered. The disadvantages of inexpensive dermoscopy can be quickly substantially mitigated with a suitable calibration procedure. © 2011 John Wiley & Sons A/S.

  17. Luminance and chromatic contributions to a hyperacuity task: isolation by contrast polarity and target separation

    PubMed Central

    Sun, Hao; Cooper, Bonnie; Lee, Barry B.

    2012-01-01

    Vernier thresholds are known to be elevated when a target pair has opposite contrast polarity. Polarity reversal is used to assess the role of luminance and chromatic pathways in hyperacuity performance. Psychophysical hyperacuity thresholds were measured for pairs of gratings of various combinations of luminance (Lum) and chromatic (Chr) contrast polarities, at different ratios of luminance to chromatic contrast. With two red-green gratings of matched luminance and chromatic polarity (+Lum+Chr), there was an elevation of threshold at isoluminance. When both luminance and chromatic polarity were mismatched (−Lum−Chr), thresholds were substantially elevated under all conditions. With the same luminance contrast polarity and opposite chromatic polarity (+Lum−Chr) thresholds were only elevated close to isoluminance; in the reverse condition (−Lum+Chr), thresholds were elevated as in the −Lum−Chr condition except close to equiluminance. Similar data were obtained for gratings isolating the short-wavelength cone mechanism. Further psychophysical measurements assessed the role of target separation with matched or mismatched contrast polarity; similar results were found for luminance and chromatic gratings. Comparison physiological data were collected from parafoveal ganglion cells of the macaque retina. Positional precision of ganglion cell signals was assessed under conditions related to the psychophysical measurements. On the basis of these combined observations, it is argued that both magnocellular, parvocellular, and koniocellular pathways have access to cortical positional mechanisms associated with vernier acuity. PMID:22306680

  18. Preliminary results from DIMES: Dispersion in the ACC

    NASA Astrophysics Data System (ADS)

    Balwada, D.; Speer, K.; LaCasce, J. H.; Owens, B.

    2012-04-01

    The Diapycnal and Isopynal Mixing Experiment in the Southern Ocean (DIMES) is a CLIVAR process study designed to study mixing in the Antarctic Circumpolar Current. The experiment includes tracer release, float, and small-scale turbulence components. This presentation will report on some results of the float component, from floats deployed across the ACC in the Southeast Pacific Ocean. These are the first subsurface Lagrangian trajectories from the ACC. Floats were deployed to follow approximately a constant density surface for a period of 1-3 years. To help aid the experimental results virtual floats were advected using AVISO data and basic statistics were derived from both deployed and virtual float trajectories. Experimental design, initial results, comparison to virtual floats and single particle and relative dispersion calculations will be presented.

  19. Paper-based chromatic toxicity bioassay by analysis of bacterial ferricyanide reduction.

    PubMed

    Pujol-Vila, F; Vigués, N; Guerrero-Navarro, A; Jiménez, S; Gómez, D; Fernández, M; Bori, J; Vallès, B; Riva, M C; Muñoz-Berbel, X; Mas, J

    2016-03-03

    Water quality assessment requires a continuous and strict analysis of samples to guarantee compliance with established standards. Nowadays, the increasing number of pollutants and their synergistic effects lead to the development general toxicity bioassays capable to analyse water pollution as a whole. Current general toxicity methods, e.g. Microtox(®), rely on long operation protocols, the use of complex and expensive instrumentation and sample pre-treatment, which should be transported to the laboratory for analysis. These requirements delay sample analysis and hence, the response to avoid an environmental catastrophe. In an attempt to solve it, a fast (15 min) and low-cost toxicity bioassay based on the chromatic changes associated to bacterial ferricyanide reduction is here presented. E. coli cells (used as model bacteria) were stably trapped on low-cost paper matrices (cellulose-based paper discs, PDs) and remained viable for long times (1 month at -20 °C). Apart from bacterial carrier, paper matrices also acted as a fluidic element, allowing fluid management without the need of external pumps. Bioassay evaluation was performed using copper as model toxic agent. Chromatic changes associated to bacterial ferricyanide reduction were determined by three different transduction methods, i.e. (i) optical reflectometry (as reference method), (ii) image analysis and (iii) visual inspection. In all cases, bioassay results (in terms of half maximal effective concentrations, EC50) were in agreement with already reported data, confirming the good performance of the bioassay. The validation of the bioassay was performed by analysis of real samples from natural sources, which were analysed and compared with a reference method (i.e. Microtox). Obtained results showed agreement for about 70% of toxic samples and 80% of non-toxic samples, which may validate the use of this simple and quick protocol in the determination of general toxicity. The minimum instrumentation

  20. Mixing of Chromatic and Luminance Retinal Signals in Primate Area V1

    PubMed Central

    Li, Xiaobing; Chen, Yao; Lashgari, Reza; Bereshpolova, Yulia; Swadlow, Harvey A.; Lee, Barry B.; Alonso, Jose Manuel

    2015-01-01

    Vision emerges from activation of chromatic and achromatic retinal channels whose interaction in visual cortex is still poorly understood. To investigate this interaction, we recorded neuronal activity from retinal ganglion cells and V1 cortical cells in macaques and measured their visual responses to grating stimuli that had either luminance contrast (luminance grating), chromatic contrast (chromatic grating), or a combination of the two (compound grating). As with parvocellular or koniocellular retinal ganglion cells, some V1 cells responded mostly to the chromatic contrast of the compound grating. As with magnocellular retinal ganglion cells, other V1 cells responded mostly to the luminance contrast and generated a frequency-doubled response to equiluminant chromatic gratings. Unlike magnocellular and parvocellular retinal ganglion cells, V1 cells formed a unimodal distribution for luminance/color preference with a 2- to 4-fold bias toward luminance. V1 cells associated with positive local field potentials in deep layers showed the strongest combined responses to color and luminance and, as a population, V1 cells encoded a diverse combination of luminance/color edges that matched edge distributions of natural scenes. Taken together, these results suggest that the primary visual cortex combines magnocellular and parvocellular retinal inputs to increase cortical receptive field diversity and to optimize visual processing of our natural environment. PMID:24464943

  1. Spectral discrimination in color blind animals via chromatic aberration and pupil shape.

    PubMed

    Stubbs, Alexander L; Stubbs, Christopher W

    2016-07-19

    We present a mechanism by which organisms with only a single photoreceptor, which have a monochromatic view of the world, can achieve color discrimination. An off-axis pupil and the principle of chromatic aberration (where different wavelengths come to focus at different distances behind a lens) can combine to provide "color-blind" animals with a way to distinguish colors. As a specific example, we constructed a computer model of the visual system of cephalopods (octopus, squid, and cuttlefish) that have a single unfiltered photoreceptor type. We compute a quantitative image quality budget for this visual system and show how chromatic blurring dominates the visual acuity in these animals in shallow water. We quantitatively show, through numerical simulations, how chromatic aberration can be exploited to obtain spectral information, especially through nonaxial pupils that are characteristic of coleoid cephalopods. We have also assessed the inherent ambiguity between range and color that is a consequence of the chromatic variation of best focus with wavelength. This proposed mechanism is consistent with the extensive suite of visual/behavioral and physiological data that has been obtained from cephalopod studies and offers a possible solution to the apparent paradox of vivid chromatic behaviors in color blind animals. Moreover, this proposed mechanism has potential applicability in organisms with limited photoreceptor complements, such as spiders and dolphins.

  2. Spectral discrimination in color blind animals via chromatic aberration and pupil shape

    PubMed Central

    Stubbs, Alexander L.; Stubbs, Christopher W.

    2016-01-01

    We present a mechanism by which organisms with only a single photoreceptor, which have a monochromatic view of the world, can achieve color discrimination. An off-axis pupil and the principle of chromatic aberration (where different wavelengths come to focus at different distances behind a lens) can combine to provide “color-blind” animals with a way to distinguish colors. As a specific example, we constructed a computer model of the visual system of cephalopods (octopus, squid, and cuttlefish) that have a single unfiltered photoreceptor type. We compute a quantitative image quality budget for this visual system and show how chromatic blurring dominates the visual acuity in these animals in shallow water. We quantitatively show, through numerical simulations, how chromatic aberration can be exploited to obtain spectral information, especially through nonaxial pupils that are characteristic of coleoid cephalopods. We have also assessed the inherent ambiguity between range and color that is a consequence of the chromatic variation of best focus with wavelength. This proposed mechanism is consistent with the extensive suite of visual/behavioral and physiological data that has been obtained from cephalopod studies and offers a possible solution to the apparent paradox of vivid chromatic behaviors in color blind animals. Moreover, this proposed mechanism has potential applicability in organisms with limited photoreceptor complements, such as spiders and dolphins. PMID:27382180

  3. Abundance and diversity of archaeal accA gene in hot springs in Yunnan Province, China.

    PubMed

    Song, Zhao-Qi; Wang, Li; Wang, Feng-Ping; Jiang, Hong-Chen; Chen, Jin-Quan; Zhou, En-Min; Liang, Feng; Xiao, Xiang; Li, Wen-Jun

    2013-09-01

    It has been suggested that archaea carrying the accA gene, encoding the alpha subunit of the acetyl CoA carboxylase, autotrophically fix CO2 using the 3-hydroxypropionate/4-hydroxybutyrate pathway in low-temperature environments (e.g., soils, oceans). However, little new information has come to light regarding the occurrence of archaeal accA genes in high-temperature ecosystems. In this study, we investigated the abundance and diversity of archaeal accA gene in hot springs in Yunnan Province, China, using DNA- and RNA-based phylogenetic analyses and quantitative polymerase chain reaction. The results showed that archaeal accA genes were present and expressed in the investigated Yunnan hot springs with a wide range of temperatures (66-96 °C) and pH (4.3-9.0). The majority of the amplified archaeal accA gene sequences were affiliated with the ThAOA/HWCG III [thermophilic ammonia-oxidizing archaea (AOA)/hot water crenarchaeotic group III]. The archaeal accA gene abundance was very close to that of AOA amoA gene, encoding the alpha subunit of ammonia monooxygenase. These data suggest that AOA in terrestrial hot springs might acquire energy from ammonia oxidation coupled with CO2 fixation using the 3-hydroxypropionate/4-hydroxybutyrate pathway.

  4. An OpenACC-Based Unified Programming Model for Multi-accelerator Systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kim, Jungwon; Lee, Seyong; Vetter, Jeffrey S

    2015-01-01

    This paper proposes a novel SPMD programming model of OpenACC. Our model integrates the different granularities of parallelism from vector-level parallelism to node-level parallelism into a single, unified model based on OpenACC. It allows programmers to write programs for multiple accelerators using a uniform programming model whether they are in shared or distributed memory systems. We implement a prototype of our model and evaluate its performance with a GPU-based supercomputer using three benchmark applications.

  5. Construction of special eye models for investigation of chromatic and higher-order aberrations of eyes.

    PubMed

    Zhai, Yi; Wang, Yan; Wang, Zhaoqi; Liu, Yongji; Zhang, Lin; He, Yuanqing; Chang, Shengjiang

    2014-01-01

    An achromatic element eliminating only longitudinal chromatic aberration (LCA) while maintaining transverse chromatic aberration (TCA) is established for the eye model, which involves the angle formed by the visual and optical axis. To investigate the impacts of higher-order aberrations on vision, the actual data of higher-order aberrations of human eyes with three typical levels are introduced into the eye model along visual axis. Moreover, three kinds of individual eye models are established to investigate the impacts of higher-order aberrations, chromatic aberration (LCA+TCA), LCA and TCA on vision under the photopic condition, respectively. Results show that for most human eyes, the impact of chromatic aberration on vision is much stronger than that of higher-order aberrations, and the impact of LCA in chromatic aberration dominates. The impact of TCA is approximately equal to that of normal level higher-order aberrations and it can be ignored when LCA exists.

  6. Neuronal Mechanism for Compensation of Longitudinal Chromatic Aberration-Derived Algorithm.

    PubMed

    Barkan, Yuval; Spitzer, Hedva

    2018-01-01

    The human visual system faces many challenges, among them the need to overcome the imperfections of its optics, which degrade the retinal image. One of the most dominant limitations is longitudinal chromatic aberration (LCA), which causes short wavelengths (blue light) to be focused in front of the retina with consequent blurring of the retinal chromatic image. The perceived visual appearance, however, does not display such chromatic distortions. The intriguing question, therefore, is how the perceived visual appearance of a sharp and clear chromatic image is achieved despite the imperfections of the ocular optics. To address this issue, we propose a neural mechanism and computational model, based on the unique properties of the S -cone pathway. The model suggests that the visual system overcomes LCA through two known properties of the S channel: (1) omitting the contribution of the S channel from the high-spatial resolution pathway (utilizing only the L and M channels). (b) Having large and coextensive receptive fields that correspond to the small bistratified cells. Here, we use computational simulations of our model on real images to show how integrating these two basic principles can provide a significant compensation for LCA. Further support for the proposed neuronal mechanism is given by the ability of the model to predict an enigmatic visual phenomenon of large color shifts as part of the assimilation effect.

  7. Neuronal Mechanism for Compensation of Longitudinal Chromatic Aberration-Derived Algorithm

    PubMed Central

    Barkan, Yuval; Spitzer, Hedva

    2018-01-01

    The human visual system faces many challenges, among them the need to overcome the imperfections of its optics, which degrade the retinal image. One of the most dominant limitations is longitudinal chromatic aberration (LCA), which causes short wavelengths (blue light) to be focused in front of the retina with consequent blurring of the retinal chromatic image. The perceived visual appearance, however, does not display such chromatic distortions. The intriguing question, therefore, is how the perceived visual appearance of a sharp and clear chromatic image is achieved despite the imperfections of the ocular optics. To address this issue, we propose a neural mechanism and computational model, based on the unique properties of the S-cone pathway. The model suggests that the visual system overcomes LCA through two known properties of the S channel: (1) omitting the contribution of the S channel from the high-spatial resolution pathway (utilizing only the L and M channels). (b) Having large and coextensive receptive fields that correspond to the small bistratified cells. Here, we use computational simulations of our model on real images to show how integrating these two basic principles can provide a significant compensation for LCA. Further support for the proposed neuronal mechanism is given by the ability of the model to predict an enigmatic visual phenomenon of large color shifts as part of the assimilation effect. PMID:29527525

  8. Airborne Cloud Computing Environment (ACCE)

    NASA Technical Reports Server (NTRS)

    Hardman, Sean; Freeborn, Dana; Crichton, Dan; Law, Emily; Kay-Im, Liz

    2011-01-01

    Airborne Cloud Computing Environment (ACCE) is JPL's internal investment to improve the return on airborne missions. Improve development performance of the data system. Improve return on the captured science data. The investment is to develop a common science data system capability for airborne instruments that encompasses the end-to-end lifecycle covering planning, provisioning of data system capabilities, and support for scientific analysis in order to improve the quality, cost effectiveness, and capabilities to enable new scientific discovery and research in earth observation.

  9. Tolerance to wood preservatives by copper-tolerant wood-rot fungi native to south-central Chile.

    PubMed

    Guillén, Yudith; Navias, David; Machuca, Angela

    2009-02-01

    Understanding the effect of heavy metals and wood preservatives on the growth of wood-rot fungi native to a certain region may improve reliability in determining the effectiveness of antifungal products, particularly when dealing with new formulations. In this investigation, strains of copper-tolerant wood-rot fungi native to south-central Chile were evaluated against two preservatives: commercial chromated copper arsenate type C (CCA-C) and a new formulation with boron and silicon (BS). Thirteen native strains, mainly white-rot fungi, were selected for their high growth rates in solid medium containing 3 mM of copper. A short-term test was then carried out, consisting of adding cellulose disks impregnated with different concentrations of preservatives to solid culture media inoculated with selected copper tolerant strains. There was a great variability in interspecific and intraspecific responses to the presence of copper and preservatives in culture media. Among the native and commercial strains evaluated, the white-rot fungi Trametes versicolor 38 and mainly Ganoderma australe 100 were notable for their tolerance to all the CCA-C and BS concentrations. The brown-rot fungus Wolfiporia cocos, used as reference strain, showed a high tolerance to CCA-C, but not to BS preservative. T. versicolor 38 and G. australe 100 were selected for subsequent studies on preserved wood degradation.

  10. Using chromate to investigate the impact of natural organics on the surface reactivity of nanoparticulate magnetite

    USGS Publications Warehouse

    Swindle, Andrew L.; Cozzarelli, Isabelle M.; Elwood Madden, Andrew S.

    2015-01-01

    Chromate was used as a chemical probe to investigate the size-dependent influence of organics on nanoparticle surface reactivity. Magnetite–chromate sorption experiments were conducted with ∼90 and ∼6 nm magnetite nanoparticles in the presence and absence of fulvic acid (FA), natural organic matter (NOM), and isolated landfill leachate (LL). Results indicated that low concentrations (1 mg/L) of organics had no noticeable impact on chromate sorption, whereas concentrations of 50 mg/L or more resulted in decreased amounts of chromate sorption. The adsorption of organics onto the magnetite surfaces interfered equally with the ability of the 6 and 90 nm particles to sorb chromate from solution, despite the greater surface area of the smaller particles. Results indicate the presence of organics did not impact the redox chemistry of the magnetite–chromate system over the duration of the experiments (8 h), nor did the organics interact with the chromate in solution. Brunauer–Emmett–Teller (BET) and scanning electron microscopy (SEM) results indicate that the organics blocked the surface reactivity by occupying surface sites on the particles. The similarity of results with FA and NOM suggests that coverage of the reactive mineral surface is the main factor behind the inhibition of surface reactivity in the presence of organics.

  11. Distal truncation of KCC3 in non-French Canadian HMSN/ACC families.

    PubMed

    Salin-Cantegrel, A; Rivière, J-B; Dupré, N; Charron, F M; Shekarabi, M; Karéméra, L; Gaspar, C; Horst, J; Tekin, M; Deda, G; Krause, A; Lippert, M M; Willemsen, M A A P; Jarrar, R; Lapointe, J-Y; Rouleau, G A

    2007-09-25

    Hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC) is a severe and progressive autosomal recessive polyneuropathy. Mutations in the potassium-chloride cotransporter 3 gene (KCC3) were identified as responsible for HMSN/ACC in the French Canadian (FC) population. In the present study, the authors were interested in finding new mutations in non-FC populations, assessing the activity of mutant proteins and refining genotype-phenotype correlations. The authors screened KCC3 for mutations using direct sequencing in six non-FC HMSN/ACC families. They then assessed the functionality of the most common mutant protein using a flux assay in Xenopus laevis oocytes. The authors identified mutations in exon 22 of KCC3: a novel mutation (del + 2994-3003; E1015X) in one family, as well as a known mutation (3031C-->T; R1011X) found in five unrelated families and associated with two different haplotypes. The function of the cotransporter was abolished, although a limited amount of mutant proteins were correctly localized at the membrane. KCC3 mutations in exon 22 constitute a recurrent mutation site for hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC), regardless of ethnic origin, and are the most common cause of HMSN/ACC in the non-French Canadian (FC) families analyzed so far. Therefore, for genetic analysis, exon 22 screening should be prioritized in non-FC populations. Finally, the R1011X mutation leads to the abrogation of KCC3's function in Xenopus laevis oocytes, likely due to impaired transit of the cotransporter.

  12. Luminance and chromatic contributions to a hyperacuity task: isolation by contrast polarity and target separation.

    PubMed

    Sun, Hao; Cooper, Bonnie; Lee, Barry B

    2012-03-01

    Vernier thresholds are known to be elevated when a target pair has opposite contrast polarity. Polarity reversal is used to assess the role of luminance and chromatic pathways in hyperacuity performance. Psychophysical hyperacuity thresholds were measured for pairs of gratings of various combinations of luminance (Lum) and chromatic (Chr) contrast polarities, at different ratios of luminance to chromatic contrast. With two red-green gratings of matched luminance and chromatic polarity (+Lum+Chr), there was an elevation of threshold at isoluminance. When both luminance and chromatic polarity were mismatched (-Lum-Chr), thresholds were substantially elevated under all conditions. With the same luminance contrast polarity and opposite chromatic polarity (+Lum-Chr) thresholds were only elevated close to isoluminance; in the reverse condition (-Lum+Chr), thresholds were elevated as in the -Lum-Chr condition except close to equiluminance. Similar data were obtained for gratings isolating the short-wavelength cone mechanism. Further psychophysical measurements assessed the role of target separation with matched or mismatched contrast polarity; similar results were found for luminance and chromatic gratings. Comparison physiological data were collected from parafoveal ganglion cells of the macaque retina. Positional precision of ganglion cell signals was assessed under conditions related to the psychophysical measurements. On the basis of these combined observations, it is argued that both magnocellular, parvocellular, and koniocellular pathways have access to cortical positional mechanisms associated with vernier acuity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Pupillometer-based objective chromatic perimetry in normal eyes and patients with retinal photoreceptor dystrophies.

    PubMed

    Skaat, Alon; Sher, Ifat; Kolker, Andrew; Elyasiv, Sivan; Rosenfeld, Elkana; Mhajna, Mohamad; Melamed, Shlomo; Belkin, Michael; Rotenstreich, Ygal

    2013-04-17

    To evaluate a novel objective perimetry using multifocal chromatic pupil light reflex in normal participants and patients with photoreceptor dysfunction, and to relate this new technique with subjective dark-adapted chromatic Goldmann perimetry. Thirty-two eyes of 17 retinitis pigmentosa (RP) or cone-rod dystrophy patients and 20 eyes of 12 healthy individuals were tested. A computerized infrared video pupillometer was used to record changes in pupil diameter in response to short- and long-wavelength stimuli (peak 485 and 640 nm, respectively; light intensity 40 cd/m(2)) at 13 different points of the 30° visual field (VF), under background illumination of 2.7 cd/m(2). The pupillary response (PR) of patients was compared with PR obtained from normal control participants. In 11 patients, the pupillary responses were also compared with their findings on dark-adapted chromatic Goldmann perimetry. Significantly reduced pupillary responses were obtained in RP patients in response to the short-wavelength stimulus in nearly all perimetric locations (P < 0.03). By contrast, in response to the long-wavelength stimulus, RP patients demonstrated significantly reduced PR mostly in peripheral locations (P ≤ 0.02). In a cone-rod dystrophy patient, the PR to both long- and short-wavelength stimuli was significantly lower in the scotoma area identified by the dark-adapted chromatic Goldmann perimetry. In all patients that were tested by the chromatic Goldmann, minimal PR was recorded in areas that were nondetected in the chromatic Goldmann perimetry. This study demonstrates the potential feasibility of using pupillometer-based chromatic perimetry for objectively assessing VF defects and retinal function in patients with retinal dystrophies. (ClinicalTrials.gov number, NCT01021982.).

  14. Reversible Chromatic Response of Polydiacetylene Derivative Vesicles in D2O Solvent.

    PubMed

    Shin, Min Jae; Kim, Jong-Duk

    2016-01-26

    The thermal chromatic sensitivity of polydiacetylenes (PDAs) with 10,12-pentacosadiynoic acid (PCDA) derivatives, which have a hydroxyl group (HEEPCDA) and an amine group (APPCDA), were investigated using D2O and H2O as solvents. The vesicle solution with polymerized HEEPCDA exhibited a reversible chromatic response during the heating and cooling cycle in D2O, but not in H2O. On the other hand, the vesicle solution with the polymerized APPCDA exhibited a reversible chromatic response in H2O during the heating and cooling cycle, but the color of the solution did not change much in D2O. The critical vesicle concentration of HEEPCDA was lower in D2O than in H2O, and the chromatic sensitivity of the polymerized vesicles to temperature was slower in D2O than in H2O. We think that it is due to D2O being a more highly structured solvent than H2O with the hydrogen bonding in D2O stronger than that in H2O.

  15. Les grands accélérateurs de particules

    NASA Astrophysics Data System (ADS)

    Patoux, A.; Perot, J.

    1991-02-01

    The different types of accelerators are recalled with emphasis on the most powerful : the synchrotron particle colliders. The use of superconductors in accelerator magnets as well as in RF cavities is discussed. The characteristics of the large accelerators, existing and planned, are given together with the level of industry involvement in their construction. Details concerning superconducting magnets and cryogenic plants are investigated. Finally, detectors, the most important tool for physics, are mentionned. Après avoir rappelé les différents types d'accélérateurs utilisés, l'accent est mis sur les plus puissants, c'est-à-dire les synchrotrons fonctionnant en anneaux de collision. Le rôle des supraconducteurs est analysé aussi bien pour les aimants que pour les cavités accélératrices. Les caractéristiques des principaux accélérateurs existants ou en projet sont données ainsi que l'implication de l'industrie dans leur fabrication. On insiste plus particulièrement sur les aimants supraconducteurs et les installations cryogéniques. Enfin les détecteurs, éléments indispensables à la physique, sont également évoqués.

  16. Fast online simultaneous monitoring of PMD and chromatic dispersion with reduced polarization dependent gain

    NASA Astrophysics Data System (ADS)

    Ning, G.; Shum, P.; Aditya, S.; Gong, Yandong

    2006-09-01

    We use the expression relating the output state of polarization and PMD vector. Based on this expression we get the power fading including first-order PMD and chromatic dispersion, which is dependent on the angle of precession of output state of polarization around the PMD vector. From the expression for power fading, we get the average power penalty for chromatic dispersion and PMD. We propose a novel and fast PMD and chromatic dispersion monitoring technology. Measured results agree well with theoretical analysis.

  17. Mitigating chromatic effects for the transverse focusing of intense charged particle beams

    NASA Astrophysics Data System (ADS)

    Mitrani, James; Kaganovich, Igor; Davidson, Ronald

    2013-09-01

    A final focusing scheme designed to minimize chromatic effects is discussed. Solenoids are often used for transverse focusing in accelerator systems that require a charged particle beam with a small focal spot and/or large energy density A sufficiently large spread in axial momentum will reduce the effectiveness of transverse focusing, and result in chromatic effects on the final focal spot. Placing a weaker solenoid upstream of a stronger final focusing solenoid (FFS) mitigates chromatic effects on transverse beam focusing. J.M. Mitrani et al., Nucl. Inst. Meth. Phys. Res. A (2013) http://dx.doi.org/10.1016/j.nima.2013.05.09 This work was supported by DOE contract DE-AC02-09CH11466.

  18. Precipitation of ACC in liposomes-a model for biomineralization in confined volumes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tester, Chantel C; Wu, Ching-Hsuan; Weigand, Steven

    2013-01-10

    Biomineralizing organisms frequently precipitate minerals in small phospholipid bilayer-delineated compartments. We have established an in vitro model system to investigate the effect of confinement in attoliter to femtoliter volumes on the precipitation of calcium carbonate. In particular, we analyze the growth and stabilization of liposome-encapsulated amorphous calcium carbonate (ACC) nanoparticles using a combination of in situ techniques, cryo-transmission electron microscopy (Cryo-TEM), and small angle X-ray scattering (SAXS). Herein, we discuss ACC nanoparticle growth rate as a function of liposome size, carbon dioxide flux across the liposome membrane, pH, and osmotic pressure. Based on these experiments, we argue that the stabilizationmore » of ACC nanoparticles in liposomes is a consequence of a low nucleation rate (high activation barrier) of crystalline polymorphs of calcium carbonate.« less

  19. Comparative study of Nd:YAG laser-induced breakdown spectroscopy and transversely excited atmospheric CO2 laser-induced gas plasma spectroscopy on chromated copper arsenate preservative-treated wood.

    PubMed

    Khumaeni, Ali; Lie, Zener Sukra; Niki, Hideaki; Lee, Yong Inn; Kurihara, Kazuyoshi; Wakasugi, Motoomi; Takahashi, Touru; Kagawa, Kiichiro

    2012-03-01

    Taking advantage of the specific characteristics of a transversely excited atmospheric (TEA) CO(2) laser, a sophisticated technique for the analysis of chromated copper arsenate (CCA) in wood samples has been developed. In this study, a CCA-treated wood sample with a dimension of 20 mm × 20 mm and a thickness of 2 mm was attached in contact to a nickel plate (20 mm × 20 mm × 0.15 mm), which functions as a subtarget. When the TEA CO(2) laser was successively irradiated onto the wood surface, a hole with a diameter of approximately 2.5 mm was produced inside the sample and the laser beam was directly impinged onto the metal subtarget. Strong and stable gas plasma with a very large diameter of approximately 10 mm was induced once the laser beam had directly struck the metal subtarget. This gas plasma then interacted with the fine particles of the sample inside the hole and finally the particles were effectively dissociated and excited in the gas plasma region. By using this technique, high precision and sensitive analysis of CCA-treated wood sample was realized. A linear calibration curve of Cr was successfully made using the CCA-treated wood sample. The detection limits of Cr, Cu, and As were estimated to be approximately 1, 2, and 15 mg/kg, respectively. In the case of standard LIBS using the Nd:YAG laser, the analytical intensities fluctuate and the detection limit was much lower at approximately one-tenth that of TEA CO(2) laser. © 2012 Optical Society of America

  20. Impaired Voluntary Control in PTSD: Probing Self-Regulation of the ACC With Real-Time fMRI

    PubMed Central

    Zweerings, Jana; Pflieger, Eliza M.; Mathiak, Krystyna A.; Zvyagintsev, Mikhail; Kacela, Anastasia; Flatten, Guido; Mathiak, Klaus

    2018-01-01

    Background: Post-traumatic stress disorder (PTSD) is characterized by deficits in the self-regulation of cognitions and emotions. Neural networks of emotion regulation may exhibit reduced control mediated by the anterior cingulate cortex (ACC), contributing to aberrant limbic responses in PTSD. Methods: Real-time fMRI neurofeedback (rt-fMRI NF) assessed self-regulation of the ACC in nine patients with PTSD after single trauma exposure and nine matched healthy controls. All participants were instructed to train ACC upregulation on three training days. Results: Both groups achieved regulation, which was associated with wide-spread brain activation encompassing the ACC. Compared to the controls, regulation amplitude and learning rate was lower in patients, correlating with symptom severity. In addition, a frontopolar activation cluster was associated with self-regulation efforts in patients. Conclusions: For the first time, we tested self-regulation of the ACC in patients with PTSD. The observed impairment supports models of ACC-mediated regulation deficits that may contribute to the psychopathology of PTSD. Controlled trials in a larger sample are needed to confirm our findings and to directly investigate whether training of central regulation mechanisms improves emotion regulation in PTSD. PMID:29899712

  1. Impaired Voluntary Control in PTSD: Probing Self-Regulation of the ACC With Real-Time fMRI.

    PubMed

    Zweerings, Jana; Pflieger, Eliza M; Mathiak, Krystyna A; Zvyagintsev, Mikhail; Kacela, Anastasia; Flatten, Guido; Mathiak, Klaus

    2018-01-01

    Background: Post-traumatic stress disorder (PTSD) is characterized by deficits in the self-regulation of cognitions and emotions. Neural networks of emotion regulation may exhibit reduced control mediated by the anterior cingulate cortex (ACC), contributing to aberrant limbic responses in PTSD. Methods: Real-time fMRI neurofeedback (rt-fMRI NF) assessed self-regulation of the ACC in nine patients with PTSD after single trauma exposure and nine matched healthy controls. All participants were instructed to train ACC upregulation on three training days. Results: Both groups achieved regulation, which was associated with wide-spread brain activation encompassing the ACC. Compared to the controls, regulation amplitude and learning rate was lower in patients, correlating with symptom severity. In addition, a frontopolar activation cluster was associated with self-regulation efforts in patients. Conclusions: For the first time, we tested self-regulation of the ACC in patients with PTSD. The observed impairment supports models of ACC-mediated regulation deficits that may contribute to the psychopathology of PTSD. Controlled trials in a larger sample are needed to confirm our findings and to directly investigate whether training of central regulation mechanisms improves emotion regulation in PTSD.

  2. Mixing of Chromatic and Luminance Retinal Signals in Primate Area V1.

    PubMed

    Li, Xiaobing; Chen, Yao; Lashgari, Reza; Bereshpolova, Yulia; Swadlow, Harvey A; Lee, Barry B; Alonso, Jose Manuel

    2015-07-01

    Vision emerges from activation of chromatic and achromatic retinal channels whose interaction in visual cortex is still poorly understood. To investigate this interaction, we recorded neuronal activity from retinal ganglion cells and V1 cortical cells in macaques and measured their visual responses to grating stimuli that had either luminance contrast (luminance grating), chromatic contrast (chromatic grating), or a combination of the two (compound grating). As with parvocellular or koniocellular retinal ganglion cells, some V1 cells responded mostly to the chromatic contrast of the compound grating. As with magnocellular retinal ganglion cells, other V1 cells responded mostly to the luminance contrast and generated a frequency-doubled response to equiluminant chromatic gratings. Unlike magnocellular and parvocellular retinal ganglion cells, V1 cells formed a unimodal distribution for luminance/color preference with a 2- to 4-fold bias toward luminance. V1 cells associated with positive local field potentials in deep layers showed the strongest combined responses to color and luminance and, as a population, V1 cells encoded a diverse combination of luminance/color edges that matched edge distributions of natural scenes. Taken together, these results suggest that the primary visual cortex combines magnocellular and parvocellular retinal inputs to increase cortical receptive field diversity and to optimize visual processing of our natural environment. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. Photographic simulation of off-axis blurring due to chromatic aberration in spectacle lenses.

    PubMed

    Doroslovački, Pavle; Guyton, David L

    2015-02-01

    Spectacle lens materials of high refractive index (nd) tend to have high chromatic dispersion (low Abbé number [V]), which may contribute to visual blurring with oblique viewing. A patient who noted off-axis blurring with new high-refractive-index spectacle lenses prompted us to do a photographic simulation of the off-axis aberrations in 3 readily available spectacle lens materials, CR-39 (nd = 1.50), polyurethane (nd = 1.60), and polycarbonate (nd = 1.59). Both chromatic and monochromatic aberrations were found to cause off-axis image degradation. Chromatic aberration was more prominent in the higher-index materials (especially polycarbonate), whereas the lower-index CR-39 had more astigmatism of oblique incidence. It is important to consider off-axis aberrations when a patient complains of otherwise unexplained blurred vision with a new pair of spectacle lenses, especially given the increasing promotion of high-refractive-index materials with high chromatic dispersion. Copyright © 2015 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  4. The effects of the wood preservative copper dimethyldithiocarbamate in the hippocampus of maternal and newborn Long-Evans rats.

    PubMed

    Scharf, Brian; Trombetta, Louis David

    2007-11-01

    The potential toxic effects on human health and deleterious effects to the environment by copper dimethyldithiocarbamate (CDDC), an alternative wood preservative to chromated copper arsenate (CCA) have not been investigated. This study describes the neurotoxicity and accumulation of copper in the hippocampus of maternal and newborn Long-Evans rats following a subacute exposure to CDDC. Pregnant rats (220-270g) were treated daily with 0mg/kg, 25mg/kg, 50mg/kg, or 75mg/kg CDDC by oral gavage starting from day 6 of gestation and continuing to parturition. Following parturition, maternal and newborn rats were euthanized and brain tissues were removed, processed, and stored for analysis. Electron microscopy revealed demyelination and by-products of peroxidative damage in treated maternal hippocampi. Treated newborn hippocampi exhibited numerous degenerating mitochondria, membrane bound inclusion bodies, and vacuoles containing degraded structures. Graphite furnace atomic absorption spectrophotometry (GFAAS) demonstrated a significant increase in copper concentration in the tissues of treated animals as compared to controls. Western blot analysis revealed an induction of stress proteins HO-1 and Hsp70 and the formation of 4-hydroxy-2-nonenal (4HNE) adducts. CDDC was shown to be toxic to the brains, at all doses used and this toxicity is attributable to copper-induced lipid peroxidation.

  5. [Isolation, identification and characterization of ACC deaminase-containing endophytic bacteria from halophyte Suaeda salsa].

    PubMed

    Teng, Songshan; Liu, Yanping; Zhao, Lei

    2010-11-01

    We Isolated and characterized 1-aminocyclopropane-1-carboxylate (ACC) deaminase-containing endophytic bacteria from halophyte Suaeda salsa to understand the interactions between endophytes and halophyte. ACC deaminase-containing endophytic bacteria were isolated from root, stalk and leaf of Suaeda salsa and were identified based on morphological, physiological-biochemical properties, API and 16S rRNA sequence analysis. Isolates were evaluated for their ACC deaminase, antifungal, protease activity, siderophores and phytohormones, such as indole-3-acetic acid, gibberellic acid and abscisic acid production, as well as atmospheric nitrogen fixation and phosphate solubilization. Four ACC deaminase-containing endophytic bacteria strains named as LP11, SS12, TW1 and TW2 were isolated and identified as Pseudomonas oryzihabitans, Pseudomonas sp., Pantoea agglomerans and Pseudomonas putida respectively. All the strains possessed the phosphate-solubilizing ability and could produce siderophores and phytohormones more or less. None of them could fix atmospheric nitrogen or produce protease. Only strain SS12 showed antagonism against two phytopathogenic fungi viz Fusarium oxysporum f. sp. conglutinans and F. oxysporum f. sp. cucumerinum. ACC deaminase-containing endophytic bacteria of Pseudomonas sp. and Pantoea sp. isolated from halophyte Suaeda salsa have abundant biological characteristics related to plant growth promotion, stress homeostasis regulation and biocontrol activity.

  6. Effects of visual attention on chromatic and achromatic detection sensitivities.

    PubMed

    Uchikawa, Keiji; Sato, Masayuki; Kuwamura, Keiko

    2014-05-01

    Visual attention has a significant effect on various visual functions, such as response time, detection and discrimination sensitivity, and color appearance. It has been suggested that visual attention may affect visual functions in the early visual pathways. In this study we examined selective effects of visual attention on sensitivities of the chromatic and achromatic pathways to clarify whether visual attention modifies responses in the early visual system. We used a dual task paradigm in which the observer detected a peripheral test stimulus presented at 4 deg eccentricities while the observer concurrently carried out an attention task in the central visual field. In experiment 1, it was confirmed that peripheral spectral sensitivities were reduced more for short and long wavelengths than for middle wavelengths with the central attention task so that the spectral sensitivity function changed its shape by visual attention. This indicated that visual attention affected the chromatic response more strongly than the achromatic response. In experiment 2 it was obtained that the detection thresholds increased in greater degrees in the red-green and yellow-blue chromatic directions than in the white-black achromatic direction in the dual task condition. In experiment 3 we showed that the peripheral threshold elevations depended on the combination of color-directions of the central and peripheral stimuli. Since the chromatic and achromatic responses were separately processed in the early visual pathways, the present results provided additional evidence that visual attention affects responses in the early visual pathways.

  7. Fluctuations in the prevalence of chromate allergy in Denmark and exposure to chrome-tanned leather.

    PubMed

    Carøe, Caroline; Andersen, Klaus E; Thyssen, Jacob P; Mortz, Charlotte G

    2010-12-01

    A recent Danish study showed a significant increase in the prevalence of chromate contact allergy after the mid-1990s, probably as a result of exposure to leather products. To reproduce the results by analysing data from the period 1992-2009 at Odense University Hospital, Denmark. The temporal development in the occurrence of chromate contact allergy and assumed causative exposures were investigated. A retrospective analysis of patch test data was performed (n = 8483), and medical charts from patients with chromate allergy (n = 231) were reviewed. Comparisons were made using the χ(2) -test. A test of the reproducibility of the TRUE Test® was also performed. Logistic regression analyses were used to test for associations. No significant changes in the prevalence or exposure sources of chromate allergy during 1992-2009 were identified. Leather shoes (24.4%) were the most frequent exposure sources in chromate allergy, and were mainly registered in women, although the difference between men and women was not significant (P = 0.07). Cement and leather glove exposure occurred significantly more often in men than in women (P = 0.002). Foot dermatitis (40.3%) was the most frequent anatomical location, apart from hand eczema (60.6%). The reproducibility of the TRUE Test® was 93.3%. Apart from hand eczema, the most frequent clinical picture of chromate allergy was foot dermatitis caused by leather shoe exposure. A tendency for an increasing prevalence of chromate contact allergy from 1997 was shown, but no significant change was detectable. © 2010 John Wiley & Sons A/S.

  8. An ACC Design Method for Achieving Both String Stability and Ride Comfort

    NASA Astrophysics Data System (ADS)

    Yamamura, Yoshinori; Seto, Yoji; Nishira, Hikaru; Kawabe, Taketoshi

    An investigation was made of a method for designing adaptive cruise control (ACC) so as to achieve a headway distance response that feels natural to the driver while at the same time obtaining high levels of both string stability and ride comfort. With this design method, the H∞ norm is adopted as the index of string stability. Additionally, two norms are introduced for evaluating ride comfort and natural vehicle behavior. The relationship between these three norms and headway distance response characteristics was analyzed, and an evaluation method was established for achieving high levels of the various performance characteristics required of ACC. An ACC system designed with this method was evaluated in driving tests conducted on a proving ground course, and the results confirmed that it achieved the targeted levels of string stability, ride comfort and natural vehicle behavior.

  9. Effectiveness of rhizobacteria containing ACC deaminase for growth promotion of peas (Pisum sativum) under drought conditions.

    PubMed

    Zahir, Z A; Munir, A; Asghar, H N; Shaharoona, B; Arshad, M

    2008-05-01

    A series of experiments were conducted to assess the effectiveness of rhizobacteria containing 1-aminocyclopropane- 1-carboxylate (ACC) deaminase for growth promotion of peas under drought conditions. Ten rhizobacteria isolated from the rhizosphere of different crops (peas, wheat, and maize) were screened for their growth promoting ability in peas under axenic condition. Three rhizobacterial isolates, Pseudomonas fluorescens biotype G (ACC-5), P. fluorescens (ACC-14), and P. putida biotype A (Q-7), were selected for pot trial on the basis of their source, ACC deaminase activity, root colonization, and growth promoting activity under axenic conditions. Inoculated and uninoculated (control) seeds of pea cultivar 2000 were sown in pots (4 seeds/pot) at different soil moisture levels (25, 50, 75, and 100% of field capacity). Results revealed that decreasing the soil moisture levels from 100 to 25% of field capacity significantly decreased the growth of peas. However, inoculation of peas with rhizobacteria containing ACC deaminase significantly decreased the "drought stress imposed effects" on growth of peas, although with variable efficacy at different moisture levels. At the lowest soil moisture level (25% field capacity), rhizobacterial isolate Pseudomonas fluorescens biotype G (ACC-5) was found to be more promising compared with the other isolates, as it caused maximum increases in fresh weight, dry weight, root length, shoot length, number of leaves per plant, and water use efficiency on fresh and dry weight basis (45, 150, 92, 45, 140, 46, and 147%, respectively) compared with respective uninoculated controls. It is highly likely that rhizobacteria containing ACC deaminase might have decreased the drought-stress induced ethylene in inoculated plants, which resulted in better growth of plants even at low moisture levels. Therefore, inoculation with rhizobacteria containing ACC deaminase could be helpful in eliminating the inhibitory effects of drought stress on the

  10. Effect of Kombucha tea on chromate(VI)-induced oxidative stress in albino rats.

    PubMed

    Sai Ram, M; Anju, B; Pauline, T; Dipti, P; Kain, A K; Mongia, S S; Sharma, S K; Singh, B; Singh, R; Ilavazhagan, G; Kumar, D; Selvamurthy, W

    2000-07-01

    The effect of Kombucha tea (KT) on oxidative stress induced changes in rats subjected to chromate treatment are reported. KT feeding alone did not show any significant change in malondialdehyde (MDA) and reduced glutathione (GSH) levels, but did enhance humoral response and delayed type of hypersensitivity (DTH) response appreciably over control animals. Chromate treatment significantly enhanced plasma and tissue MDA levels, decreased DTH response considerably, enhanced glutathione peroxidase and catalase activities; however, no change in GSH, superoxide dismutase and antibody titres was noticed. KT feeding completely reversed the chromate-induced changes. These results show that Kombucha tea has potent anti-oxidant and immunopotentiating activities.

  11. Chromatic and Achromatic Spatial Resolution of Local Field Potentials in Awake Cortex

    PubMed Central

    Jansen, Michael; Li, Xiaobing; Lashgari, Reza; Kremkow, Jens; Bereshpolova, Yulia; Swadlow, Harvey A.; Zaidi, Qasim; Alonso, Jose-Manuel

    2015-01-01

    Local field potentials (LFPs) have become an important measure of neuronal population activity in the brain and could provide robust signals to guide the implant of visual cortical prosthesis in the future. However, it remains unclear whether LFPs can detect weak cortical responses (e.g., cortical responses to equiluminant color) and whether they have enough visual spatial resolution to distinguish different chromatic and achromatic stimulus patterns. By recording from awake behaving macaques in primary visual cortex, here we demonstrate that LFPs respond robustly to pure chromatic stimuli and exhibit ∼2.5 times lower spatial resolution for chromatic than achromatic stimulus patterns, a value that resembles the ratio of achromatic/chromatic resolution measured with psychophysical experiments in humans. We also show that, although the spatial resolution of LFP decays with visual eccentricity as is also the case for single neurons, LFPs have higher spatial resolution and show weaker response suppression to low spatial frequencies than spiking multiunit activity. These results indicate that LFP recordings are an excellent approach to measure spatial resolution from local populations of neurons in visual cortex including those responsive to color. PMID:25416722

  12. Neurochemical responses to chromatic and achromatic stimuli in the human visual cortex.

    PubMed

    Bednařík, Petr; Tkáč, Ivan; Giove, Federico; Eberly, Lynn E; Deelchand, Dinesh K; Barreto, Felipe R; Mangia, Silvia

    2018-02-01

    In the present study, we aimed at determining the metabolic responses of the human visual cortex during the presentation of chromatic and achromatic stimuli, known to preferentially activate two separate clusters of neuronal populations (called "blobs" and "interblobs") with distinct sensitivity to color or luminance features. Since blobs and interblobs have different cytochrome-oxidase (COX) content and micro-vascularization level (i.e., different capacities for glucose oxidation), different functional metabolic responses during chromatic vs. achromatic stimuli may be expected. The stimuli were optimized to evoke a similar load of neuronal activation as measured by the bold oxygenation level dependent (BOLD) contrast. Metabolic responses were assessed using functional 1 H MRS at 7 T in 12 subjects. During both chromatic and achromatic stimuli, we observed the typical increases in glutamate and lactate concentration, and decreases in aspartate and glucose concentration, that are indicative of increased glucose oxidation. However, within the detection sensitivity limits, we did not observe any difference between metabolic responses elicited by chromatic and achromatic stimuli. We conclude that the higher energy demands of activated blobs and interblobs are supported by similar increases in oxidative metabolism despite the different capacities of these neuronal populations.

  13. Chromatic and Achromatic Spatial Resolution of Local Field Potentials in Awake Cortex.

    PubMed

    Jansen, Michael; Li, Xiaobing; Lashgari, Reza; Kremkow, Jens; Bereshpolova, Yulia; Swadlow, Harvey A; Zaidi, Qasim; Alonso, Jose-Manuel

    2015-10-01

    Local field potentials (LFPs) have become an important measure of neuronal population activity in the brain and could provide robust signals to guide the implant of visual cortical prosthesis in the future. However, it remains unclear whether LFPs can detect weak cortical responses (e.g., cortical responses to equiluminant color) and whether they have enough visual spatial resolution to distinguish different chromatic and achromatic stimulus patterns. By recording from awake behaving macaques in primary visual cortex, here we demonstrate that LFPs respond robustly to pure chromatic stimuli and exhibit ∼2.5 times lower spatial resolution for chromatic than achromatic stimulus patterns, a value that resembles the ratio of achromatic/chromatic resolution measured with psychophysical experiments in humans. We also show that, although the spatial resolution of LFP decays with visual eccentricity as is also the case for single neurons, LFPs have higher spatial resolution and show weaker response suppression to low spatial frequencies than spiking multiunit activity. These results indicate that LFP recordings are an excellent approach to measure spatial resolution from local populations of neurons in visual cortex including those responsive to color. © The Author 2014. Published by Oxford University Press.

  14. A feasibility study on porting the community land model onto accelerators using OpenACC

    DOE PAGES

    Wang, Dali; Wu, Wei; Winkler, Frank; ...

    2014-01-01

    As environmental models (such as Accelerated Climate Model for Energy (ACME), Parallel Reactive Flow and Transport Model (PFLOTRAN), Arctic Terrestrial Simulator (ATS), etc.) became more and more complicated, we are facing enormous challenges regarding to porting those applications onto hybrid computing architecture. OpenACC appears as a very promising technology, therefore, we have conducted a feasibility analysis on porting the Community Land Model (CLM), a terrestrial ecosystem model within the Community Earth System Models (CESM)). Specifically, we used automatic function testing platform to extract a small computing kernel out of CLM, then we apply this kernel into the actually CLM dataflowmore » procedure, and investigate the strategy of data parallelization and the benefit of data movement provided by current implementation of OpenACC. Even it is a non-intensive kernel, on a single 16-core computing node, the performance (based on the actual computation time using one GPU) of OpenACC implementation is 2.3 time faster than that of OpenMP implementation using single OpenMP thread, but it is 2.8 times slower than the performance of OpenMP implementation using 16 threads. On multiple nodes, MPI_OpenACC implementation demonstrated very good scalability on up to 128 GPUs on 128 computing nodes. This study also provides useful information for us to look into the potential benefits of “deep copy” capability and “routine” feature of OpenACC standards. In conclusion, we believe that our experience on the environmental model, CLM, can be beneficial to many other scientific research programs who are interested to porting their large scale scientific code using OpenACC onto high-end computers, empowered by hybrid computing architecture.« less

  15. Fastener corrosion : testing, research, and design considerations

    Treesearch

    Douglas R. Rammer; Samuel L. Zelinka; Philip Line

    2006-01-01

    In 2004, the voluntary removal of chromated copper arsenate (CCA) from residential wood construction raised concern about corrosion of metal fasteners in wood treated with replacement preservatives. Replacement preservatives contain more copper, which may increase corrosion, and do not contain chromates or arsenates, which are known corrosion inhibitors. This paper is...

  16. [Lateral chromatic aberrations correction for AOTF imaging spectrometer based on doublet prism].

    PubMed

    Zhao, Hui-Jie; Zhou, Peng-Wei; Zhang, Ying; Li, Chong-Chong

    2013-10-01

    An user defined surface function method was proposed to model the acousto-optic interaction of AOTF based on wave-vector match principle. Assessment experiment result shows that this model can achieve accurate ray trace of AOTF diffracted beam. In addition, AOTF imaging spectrometer presents large residual lateral color when traditional chromatic aberrations correcting method is adopted. In order to reduce lateral chromatic aberrations, a method based on doublet prism is proposed. The optical material and angle of the prism are optimized automatically using global optimization with the help of user defined AOTF surface. Simulation result shows that the proposed method provides AOTF imaging spectrometer with great conveniences, which reduces the lateral chromatic aberration to less than 0.000 3 degrees and improves by one order of magnitude, with spectral image shift effectively corrected.

  17. Copper-tolerant rhizosphere bacteria-characterization and assessment of plant growth promoting factors.

    PubMed

    Rathi, Manohari; Nandabalan, Yogalakshmi Kadapakkam

    2017-04-01

    Remediation of heavy metal contaminated soil is a major problem or concern worldwide. Heavy metal accumulation in the soil is increasing day by day by industries, mines, agriculture, fuel combustion and municipal waste discharge. Such contaminated soils harbour a large number of resistant microbial populations. Screening and isolation of such microbes would be utilized for natural remediation of metal contaminated soils. Therefore, in the present study, highly copper-tolerant bacteria from rhizosphere soil of Cynodon dactylon grown in brass effluent contaminated soil were isolated and assessed for plant growth promoting factors. A total of 61 isolates were isolated from the rhizosphere of three contaminated sites. Six highly copper-tolerant isolates named as MYS1, MYS2, MYS3, MYS4, MYS5 and MYS6 were isolated through enrichment in copper containing nutrient broth. 16S rRNA analysis revealed that the isolates were from genera Stenotrophomonas and Brevundimonas and belong to classes Alpha Proteobacteriacea and Gamma Proteobacteriacea, respectively. Strain MYS1, MYS2 and MYS4 showed 95-99% similarity with Stenotrophomonas acidaminiphila, strain MYS3 and MYS5 showed 99 and 97% similarity with Stenotrophomonas maltophilia and Stenotrophomonas sp. Strain MYS6 showed 94% similarity with Brevundimonas diminuta. All the rhizobacteria showed plant growth promoting traits such as production of siderophores, indole acetic acid (IAA), phosphate solubilization and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity. From this study, we can conclude that all the isolates possess copper resistance and potential for phytoremediation of copper polluted soils.

  18. [Cloning, expression and transcriptional analysis of biotin carboxyl carrier protein gene (accA) from Amycolatopsis mediterranei U32 ].

    PubMed

    Lu, Jie; Yao, Yufeng; Jiang, Weihong; Jiao, Ruishen

    2003-02-01

    Acetyl CoA carboxylase (EC 6.4.1.2, ACC) catalyzes the ATP-dependent carboxylation of acetyl CoA to yield malonyl CoA, which is the first committed step in fatty acid synthesis. A pair of degenerate PCR primers were designed according to the conserved amino acid sequence of AccA from M. tuberculosis and S. coelicolor. The product of the PCR amplification, a DNA fragment of 250bp was used as a probe for screening the U32 genomic cosmid library and its gene, accA, coding the biotinylated protein subunit of acetyl CoA carboxylase, was successfully cloned from U32. The accA ORF encodes a 598-amino-acid protein with the calculated molecular mass of 63.7kD, with 70.1% of G + C content. A typical Streptomyces RBS sequence, AGGAGG, was found at the - 6 position upstream of the start codon GTG. Analysis of the deduced amino acid sequence showed the presence of biotin-binding site and putative ATP-bicarbonate interaction region, which suggested the U32 AccA may act as a biotin carboxylase as well as a biotin carrier protein. Gene accA was then cloned into the pET28 (b) vector and expressed solubly in E. coli BL21 (DE3) by 0.1 mmol/L IPTG induction. Western blot confirmed the covalent binding of biotin with AccA. Northern blot analyzed transcriptional regulation of accA by 5 different nitrogen sources.

  19. Traverse Focusing of Intense Charged Particle Beams with Chromatic Effects for Heavy Ion Fusion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    James M. Mitrani, Igor D. Kaganovich, Ronald C. Davidson

    A fi nal focusing scheme designed to minimize chromatic effects is discussed. The Neutralized Drift Compression Experiment-II (NDCX-II) will apply a velocity tilt for longitudinal bunch compression, and a fi nal focusing solenoid (FFS) for transverse bunch compression. In the beam frame, neutralized drift compression causes a suffi ciently large spread in axial momentum, pz , resulting in chromatic effects to the fi nal focal spot during transverse bunch compression. Placing a weaker solenoid upstream of a stronger fi nal focusing solenoid (FFS) mitigates chromatic effects and improves transverse focusing by a factor of approximately 2-4 for appropriate NDCX-II parameters.

  20. Development of Chromatic Induction in Infancy

    ERIC Educational Resources Information Center

    Okamura, Hiromi; Kanazawa, So; Yamaguchi, Masami K.

    2007-01-01

    The perception of colour in an embedded field is affected by the surround colour. This phenomenon is known as chromatic induction. In the present study we investigated whether the colour perception by infants aged 5-7 months could be affected by the surround colour. In Experiments 1 and 2 each stimulus was composed of an array of six squares in…

  1. The transformation of amorphous calcium carbonate, ACC, to crystalline phases as function of time and temperature.

    NASA Astrophysics Data System (ADS)

    Gies, Hermann; Happel, Marian; Niedermayr, Andrea; Immenhauser, Adrian

    2017-04-01

    We present results from a structural study of the transformation of freeze dried amorphous calcium carbonate, ACC, in crystalline material using pair distribution function analysis, PDF analysis, of X-ray powder diffraction data, XPD data. PDF analysis allows for the analysis of local order of structural subunit in the range between molecular unit (1. and 2. coordination sphere) and long range periodicity as in crystalline materials. ACC was precipitated from aqueous solutions at 298 K and 278 K using different amounts of Mg cations as stabilizer. The samples were immediately separated from the solution and freeze dried. For the transformation study, the samples were heated and analysed using XPD until they were crystallized. The radial distribution obtained from the XPD data were compared to simulated radial distributions of the calcium carbonate polymorphs and their hydrated phases. An ACC precipitated from a solution with Ca:Mg:CO3 = 1:5:4 at 298 K (ration in mmol, pH = 8.2) and freeze dried right after isolation from the solution revealed a close resemblance with ikaite in its local order. Another ACC with Ca:Mg:CO3 = 1:10:1.4 (T = 298, pH = 8.7) showed distinctly different local order resembling monohydrocalcite. Both ACC, however, still had considerable amounts of water dominating the Ca-coordination sphere. During the transformation to calcite, the structural changes in the sample concerned the hydrate water coordinating Ca which was removed and replaced by the carbonate oxygens. The study shows that ACC obtained from different starting solutions show specific local order. Freeze drying leads to solid ACC powder which still contain considerable amounts of hydrate water. Structural subunits are distinct in ACC and different from the crystalline phase. The study supplements recent reports presented by Konrad et al., Purgstaller et al., and Tobler et al.. F. Konrad et al., Cryst. Growth Des. 16, 6310-6317(2016) B. Purgstaller et al., Geochimica et Cosmochimica

  2. Molecular cloning, expression, and stress response of the estrogen-related receptor gene (AccERR) from Apis cerana cerana

    NASA Astrophysics Data System (ADS)

    Zhang, Weixing; Zhu, Ming; Zhang, Ge; Liu, Feng; Wang, Hongfang; Guo, Xingqi; Xu, Baohua

    2016-04-01

    Estrogen-related receptor (ERR), which belongs to the nuclear receptor superfamily, has been implicated in diverse physiological processes involving the estrogen signaling pathway. However, little information is available on ERR in Apis cerana cerana. In this report, we isolated the ERR gene and investigated its involvement in antioxidant defense. Quantitative real-time polymerase chain reaction (qPCR) revealed that the highest mRNA expression occurred in eggs during different developmental stages. The expression levels of AccERR were highest in the muscle, followed by the rectum. The predicted transcription factor binding sites in the promoter of AccERR suggested that AccERR potentially functions in early development and in environmental stress responses. The expression of AccERR was induced by cold (4 °C), heat (42 °C), ultraviolet light (UV), HgCl2, and various types of pesticides (phoxim, deltamethrin, triadimefon, and cyhalothrin). Western blot was used to measure the expression levels of AccERR protein. These data suggested that AccERR might play a vital role in abiotic stress responses.

  3. Monitoring apoptosis of TK-GFP-expressing ACC-M cells induced by ACV using FRET technique

    NASA Astrophysics Data System (ADS)

    Xiong, Tao; Zhang, Zhihong; Lin, Juqiang; Yang, Jie; Zeng, Shaoqun; Luo, Qingming

    2006-05-01

    Apoptosis is an evolutionary conserved cellular process that plays an important role during development, but it is also involved in tissue homeostasis and in many diseases. To study the characteristics of suicide gene system of the herpes simplex virus thymidine kinase (HSV-tk) gene in tumor cells and explore the apoptosis phenomena in this system and its effect on the human adenoid cystic carcinoma line ACC-M cell, we detected apoptosis of CD3- (ECFP-CRS-DsRed) and TK-GFP-expressing ACC-M (ACC-M-TK-GFP-CD3) cells induced by acyclovir (ACV) using fluorescence resonance energy transfer (FRET) technique. CD3 is a FRET-based indicator for activity of caspase-3, which is composed of an enhanced cyan fluorescent protein, a caspase-3 sensitive linker, and a red fluorescent protein from Discosoma with efficient maturation property. FRET from ECFP to DsRed could be detected in normal ACC-M-TK-GFP-CD3 cells, and the FRET efficient was remarkably decreased and then disappeared during the cells apoptosis induced by ACV. It was due to the activated caspase-3 cleaved the CD3 fusion protein. In this study, the results suggested that the ACV-induced apoptosis of ACC-M-TK-GFP-CD3 cells was through caspase-3 pathway.

  4. Monitoring apoptosis of TK-GFP-expressing ACC-M cells induced by ACV using FRET technique

    NASA Astrophysics Data System (ADS)

    Xiong, Tao; Zhang, Zhihong; Lin, Juqiang; Yang, Jie; Zeng, Shaoqun; Luo, Qingming

    2006-09-01

    Apoptosis is an evolutionary conserved cellular process that plays an important role during development, but it is also involved in tissue homeostasis and in many diseases. To study the characteristics of suicide gene system of the herpes simplex virus thymidine kinase (HSV-tk) gene in tumor cells and explore the apoptosis phenomena in this system and its effect on the human adenoid cystic carcinoma line ACC-M cell, we detected apoptosis of CD3- (ECFP-CRS-DsRed) and TK-GFP-expressing ACC-M (ACC-M-TK-GFP-CD3) cells induced by acyclovir (ACV) using fluorescence resonance energy transfer (FRET) technique. CD3 is a FRET-based indicator for activity of caspase-3, which is composed of an enhanced cyan fluorescent protein, a caspase-3 sensitive linker, and a red fluorescent protein from Discosoma with efficient maturation property. FRET from ECFP to DsRed could be detected in normal ACC-M-TK-GFP-CD3 cells, and the FRET efficient was remarkably decreased and then disappeared during the cells apoptosis induced by ACV. It was due to the activated caspase-3 cleaved the CD3 fusion protein. In this study, the results suggested that the AVC-induced apoptosis of ACC-M-TK-GFP-CD3 cells was through caspase-3 pathway.

  5. A halotolerant Enterobacter sp. displaying ACC deaminase activity promotes rice seedling growth under salt stress.

    PubMed

    Sarkar, Anumita; Ghosh, Pallab Kumar; Pramanik, Krishnendu; Mitra, Soumik; Soren, Tithi; Pandey, Sanjeev; Mondal, Monohar Hossain; Maiti, Tushar Kanti

    2018-01-01

    Agricultural productivity is proven to be hampered by the synthesis of reactive oxygen species (ROS) and production of stress-induced ethylene under salinity stress. One-aminocyclopropane-1-carboxylic acid (ACC) is the direct precursor of ethylene synthesized by plants. Bacteria possessing ACC deaminase activity can use ACC as a nitrogen source preventing ethylene production. Several salt-tolerant bacterial strains displaying ACC deaminase activity were isolated from rice fields, and their plant growth-promoting (PGP) properties were determined. Among them, strain P23, identified as an Enterobacter sp. based on phenotypic characteristics, matrix-assisted laser desorption ionization-time of flight mass spectrometry data and the 16S rDNA sequence, was selected as the best-performing isolate for several PGP traits, including phosphate solubilization, IAA production, siderophore production, HCN production, etc. Enterobacter sp. P23 was shown to promote rice seedling growth under salt stress, and this effect was correlated with a decrease in antioxidant enzymes and stress-induced ethylene. Isolation of an acdS mutant strain enabled concluding that the reduction in stress-induced ethylene content after inoculation of strain P23 was linked to ACC deaminase activity. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  6. Evaluation of chromatic cues for trapping Bactrocera tau.

    PubMed

    Li, Lei; Ma, Huabo; Niu, Liming; Han, Dongyin; Zhang, Fangping; Chen, Junyu; Fu, Yueguan

    2017-01-01

    Trapping technology based on chromatic cues is an important strategy in controlling Tephritidae (fruit flies). The objectives of this present study were to evaluate the preference of Bactrocera tau for different chromatic cues, and to explore an easy method to print and reproduce coloured paper. Chromatic cues significantly affected the preference of adult B. tau. Wavelengths in the 515-604 nm range were the suitable wavelengths for trapping B. tau. Different-day-old B. tau had different colour preferences. Virtual wavelengths of 595 nm (yellow) and 568 nm (yellowish green) were the optimum wavelengths for trapping 5-7-day-old B. tau and 30-32-day-old B. tau respectively. The trap type and height significantly influenced B. tau attraction efficiency. The number of B. tau on coloured traps hung perpendicular to plant rows was not significantly higher than the number on traps hung parallel to plant rows. The quantisation of colour on the basis of Bruton's wavelength to RGB function can serve as an alternative method for printing and reproducing coloured paper, but a corrected equation should be established between the theoretical wavelength and actual wavelength of coloured paper. Results show that a compound paper coloured yellow (595 nm) and yellowish green (568 nm) installed at 60 and 90 cm above the ground shows the maximum effect for trapping B. tau. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  7. Speed and the coherence of superimposed chromatic gratings.

    PubMed

    Bosten, J M; Smith, L; Mollon, J D

    2016-05-01

    On the basis of measurements of the perceived coherence of superimposed drifting gratings, Krauskopf and Farell (1990) proposed that motion is analysed independently in different chromatic channels. They found that two gratings appeared to slip if each modulated one of the two 'cardinal' color mechanisms S/(L+M) and L/(L+M). If the gratings were defined along intermediate color directions, observers reported a plaid, moving coherently. We hypothesised that slippage might occur in chromatic gratings if the motion signal from the S/(L+M) channel is weak and equivalent to a lower speed. We asked observers to judge coherence in two conditions. In one, S/(L+M) and L/(L+M) gratings were physically the same speed. In the other, the two gratings had perceptually matched speeds. We found that the relative incoherence of cardinal gratings is the same whether gratings are physically or perceptually matched in speed. Thus our hypothesis was firmly contradicted. In a control condition, observers were asked to judge the coherence of stationary gratings. Interestingly, the difference in judged coherence between cardinal and intermediate gratings remained as strong as it was when the gratings moved. Our results suggest a possible alternative interpretation of Krauskopf and Farell's result: the processes of object segregation may precede the analysis of the motion of chromatic gratings, and the same grouping signals may prompt object segregation in the stationary and moving cases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Chromatic signals control proboscis movements during hovering flight in the hummingbird hawkmoth Macroglossum stellatarum.

    PubMed

    Goyret, Joaquín; Kelber, Almut

    2012-01-01

    Most visual systems are more sensitive to luminance than to colour signals. Animals resolve finer spatial detail and temporal changes through achromatic signals than through chromatic ones. Probably, this explains that detection of small, distant, or moving objects is typically mediated through achromatic signals. Macroglossum stellatarum are fast flying nectarivorous hawkmoths that inspect flowers with their long proboscis while hovering. They can visually control this behaviour using floral markings known as nectar guides. Here, we investigate whether this is mediated by chromatic or achromatic cues. We evaluated proboscis placement, foraging efficiency, and inspection learning of naïve moths foraging on flower models with coloured markings that offered either chromatic, achromatic or both contrasts. Hummingbird hawkmoths could use either achromatic or chromatic signals to inspect models while hovering. We identified three, apparently independent, components controlling proboscis placement: After initial contact, 1) moths directed their probing towards the yellow colour irrespectively of luminance signals, suggesting a dominant role of chromatic signals; and 2) moths tended to probe mainly on the brighter areas of models that offered only achromatic signals. 3) During the establishment of the first contact, naïve moths showed a tendency to direct their proboscis towards the small floral marks independent of their colour or luminance. Moths learned to find nectar faster, but their foraging efficiency depended on the flower model they foraged on. Our results imply that M. stellatarum can perceive small patterns through colour vision. We discuss how the different informational contents of chromatic and luminance signals can be significant for the control of flower inspection, and visually guided behaviours in general.

  9. Design and optimization of a portable LQCD Monte Carlo code using OpenACC

    NASA Astrophysics Data System (ADS)

    Bonati, Claudio; Coscetti, Simone; D'Elia, Massimo; Mesiti, Michele; Negro, Francesco; Calore, Enrico; Schifano, Sebastiano Fabio; Silvi, Giorgio; Tripiccione, Raffaele

    The present panorama of HPC architectures is extremely heterogeneous, ranging from traditional multi-core CPU processors, supporting a wide class of applications but delivering moderate computing performance, to many-core Graphics Processor Units (GPUs), exploiting aggressive data-parallelism and delivering higher performances for streaming computing applications. In this scenario, code portability (and performance portability) become necessary for easy maintainability of applications; this is very relevant in scientific computing where code changes are very frequent, making it tedious and prone to error to keep different code versions aligned. In this work, we present the design and optimization of a state-of-the-art production-level LQCD Monte Carlo application, using the directive-based OpenACC programming model. OpenACC abstracts parallel programming to a descriptive level, relieving programmers from specifying how codes should be mapped onto the target architecture. We describe the implementation of a code fully written in OpenAcc, and show that we are able to target several different architectures, including state-of-the-art traditional CPUs and GPUs, with the same code. We also measure performance, evaluating the computing efficiency of our OpenACC code on several architectures, comparing with GPU-specific implementations and showing that a good level of performance-portability can be reached.

  10. Chromatic response of polydiacetylene vesicle induced by the permeation of methotrexate.

    PubMed

    Shin, Min Jae; Kim, Ye Jin; Kim, Jong-Duk

    2015-07-07

    The noble vesicular system of polydiacetylene showed a red shift using two types of detecting systems. One of the systems involves the absorption of target materials from the outer side of the vesicle, and the other system involves the permeation through the vesicular layers from within the vesicle. The chromatic mixed vesicles of N-(2-aminoethyl)pentacosa-10,12-diynamide (AEPCDA) and dimethyldioctadecylammonium chloride (DODAC) were fabricated by sonication, followed by polymerization by UV irradiation. The stability of monomeric vesicles was observed to increase with the polymerization of the vesicles. Methotrexate was used as a target material. The polymerized mixed vesicles having a blue color were exposed to a concentration gradient of methotrexate, and a red shift was observed indicating the adsorption of methotrexate on the polydiacetylene bilayer. In order to check the chromatic change by the permeation of methotrexate, we separated the vesicle portion, which contained methotrexate inside the vesicle, and checked chromatic change during the permeation of methotrexate through the vesicle. The red shift apparently indicates the disturbance in the bilayer induced by the permeation of methotrexate. The maximum contrast of color appeared at the equal molar ratio of AEPCDA and DODAC, indicating that the formation of flexible and deformable vesicular layers is important for red shift. Therefore, it is hypothesized that the system can be applicable for the chromatic detection of the permeation of methotrexate through the polydiacetylene layer.

  11. Visual sensitivity for luminance and chromatic stimuli during the execution of smooth pursuit and saccadic eye movements.

    PubMed

    Braun, Doris I; Schütz, Alexander C; Gegenfurtner, Karl R

    2017-07-01

    Visual sensitivity is dynamically modulated by eye movements. During saccadic eye movements, sensitivity is reduced selectively for low-spatial frequency luminance stimuli and largely unaffected for high-spatial frequency luminance and chromatic stimuli (Nature 371 (1994), 511-513). During smooth pursuit eye movements, sensitivity for low-spatial frequency luminance stimuli is moderately reduced while sensitivity for chromatic and high-spatial frequency luminance stimuli is even increased (Nature Neuroscience, 11 (2008), 1211-1216). Since these effects are at least partly of different polarity, we investigated the combined effects of saccades and smooth pursuit on visual sensitivity. For the time course of chromatic sensitivity, we found that detection rates increased slightly around pursuit onset. During saccades to static and moving targets, detection rates dropped briefly before the saccade and reached a minimum at saccade onset. This reduction of chromatic sensitivity was present whenever a saccade was executed and it was not modified by subsequent pursuit. We also measured contrast sensitivity for flashed high- and low-spatial frequency luminance and chromatic stimuli during saccades and pursuit. During saccades, the reduction of contrast sensitivity was strongest for low-spatial frequency luminance stimuli (about 90%). However, a significant reduction was also present for chromatic stimuli (about 58%). Chromatic sensitivity was increased during smooth pursuit (about 12%). These results suggest that the modulation of visual sensitivity during saccades and smooth pursuit is more complex than previously assumed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Identification and characterization of an Apis cerana cerana Delta class glutathione S-transferase gene ( AccGSTD) in response to thermal stress

    NASA Astrophysics Data System (ADS)

    Yan, Huiru; Jia, Haihong; Wang, Xiuling; Gao, Hongru; Guo, Xingqi; Xu, Baohua

    2013-02-01

    Glutathione S-transferases (GSTs) are members of a multifunctional enzyme super family that plays a pivotal role in both insecticide resistance and protection against oxidative stress. In this study, we identified a single-copy gene, AccGSTD, as being a Delta class GST in the Chinese honey bee ( Apis cerana cerana). A predicted antioxidant response element, CREB, was found in the 1,492-bp 5'-flanking region, suggesting that AccGSTD may be involved in oxidative stress response pathways. Real-time PCR and immunolocalization studies demonstrated that AccGSTD exhibited both developmental- and tissue-specific expression patterns. During development, AccGSTD transcript was increased in adults. The AccGSTD expression level was the highest in the honey bee brain. Thermal stress experiments demonstrated that AccGSTD could be significantly upregulated by temperature changes in a time-dependent manner. It is hypothesized that high expression levels might be due to the increased levels of oxidative stress caused by the temperature challenges. Additionally, functional assays of the recombinant AccGSTD protein revealed that AccGSTD has the capability to protect DNA from oxidative damage. Taken together, these data suggest that AccGSTD may be responsible for antioxidant defense in adult honey bees.

  13. Sulcal Polymorphisms of the IFC and ACC Contribute to Inhibitory Control Variability in Children and Adults

    PubMed Central

    Linzarini, Adriano; Dollfus, Sonia; Etard, Olivier; Orliac, François; Houdé, Olivier

    2018-01-01

    Abstract Inhibitory control (IC) is a core executive function that enables humans to resist habits, temptations, or distractions. IC efficiency in childhood is a strong predictor of academic and professional success later in life. Based on analysis of the sulcal pattern, a qualitative feature of cortex anatomy determined during fetal life and stable during development, we searched for evidence that interindividual differences in IC partly trace back to prenatal processes. Using anatomical magnetic resonance imaging (MRI), we analyzed the sulcal pattern of two key regions of the IC neural network, the dorsal anterior cingulate cortex (ACC) and the inferior frontal cortex (IFC), which limits the inferior frontal gyrus. We found that the sulcal pattern asymmetry of both the ACC and IFC contributes to IC (Stroop score) in children and adults: participants with asymmetrical ACC or IFC sulcal patterns had better IC efficiency than participants with symmetrical ACC or IFC sulcal patterns. Such additive effects of IFC and ACC sulcal patterns on IC efficiency suggest that distinct early neurodevelopmental mechanisms targeting different brain regions likely contribute to IC efficiency. This view shares some analogies with the “common variant–small effect” model in genetics, which states that frequent genetic polymorphisms have small effects but collectively account for a large portion of the variance. Similarly, each sulcal polymorphism has a small but additive effect: IFC and ACC sulcal patterns, respectively, explained 3% and 14% of the variance of the Stroop interference scores. PMID:29527565

  14. Sulcal Polymorphisms of the IFC and ACC Contribute to Inhibitory Control Variability in Children and Adults.

    PubMed

    Tissier, Cloélia; Linzarini, Adriano; Allaire-Duquette, Geneviève; Mevel, Katell; Poirel, Nicolas; Dollfus, Sonia; Etard, Olivier; Orliac, François; Peyrin, Carole; Charron, Sylvain; Raznahan, Armin; Houdé, Olivier; Borst, Grégoire; Cachia, Arnaud

    2018-01-01

    Inhibitory control (IC) is a core executive function that enables humans to resist habits, temptations, or distractions. IC efficiency in childhood is a strong predictor of academic and professional success later in life. Based on analysis of the sulcal pattern, a qualitative feature of cortex anatomy determined during fetal life and stable during development, we searched for evidence that interindividual differences in IC partly trace back to prenatal processes. Using anatomical magnetic resonance imaging (MRI), we analyzed the sulcal pattern of two key regions of the IC neural network, the dorsal anterior cingulate cortex (ACC) and the inferior frontal cortex (IFC), which limits the inferior frontal gyrus. We found that the sulcal pattern asymmetry of both the ACC and IFC contributes to IC (Stroop score) in children and adults: participants with asymmetrical ACC or IFC sulcal patterns had better IC efficiency than participants with symmetrical ACC or IFC sulcal patterns. Such additive effects of IFC and ACC sulcal patterns on IC efficiency suggest that distinct early neurodevelopmental mechanisms targeting different brain regions likely contribute to IC efficiency. This view shares some analogies with the "common variant-small effect" model in genetics, which states that frequent genetic polymorphisms have small effects but collectively account for a large portion of the variance. Similarly, each sulcal polymorphism has a small but additive effect: IFC and ACC sulcal patterns, respectively, explained 3% and 14% of the variance of the Stroop interference scores.

  15. ACLY and ACC1 Regulate Hypoxia-Induced Apoptosis by Modulating ETV4 via α-ketoglutarate.

    PubMed

    Keenan, Melissa M; Liu, Beiyu; Tang, Xiaohu; Wu, Jianli; Cyr, Derek; Stevens, Robert D; Ilkayeva, Olga; Huang, Zhiqing; Tollini, Laura A; Murphy, Susan K; Lucas, Joseph; Muoio, Deborah M; Kim, So Young; Chi, Jen-Tsan

    2015-10-01

    In order to propagate a solid tumor, cancer cells must adapt to and survive under various tumor microenvironment (TME) stresses, such as hypoxia or lactic acidosis. To systematically identify genes that modulate cancer cell survival under stresses, we performed genome-wide shRNA screens under hypoxia or lactic acidosis. We discovered that genetic depletion of acetyl-CoA carboxylase (ACACA or ACC1) or ATP citrate lyase (ACLY) protected cancer cells from hypoxia-induced apoptosis. Additionally, the loss of ACLY or ACC1 reduced levels and activities of the oncogenic transcription factor ETV4. Silencing ETV4 also protected cells from hypoxia-induced apoptosis and led to remarkably similar transcriptional responses as with silenced ACLY or ACC1, including an anti-apoptotic program. Metabolomic analysis found that while α-ketoglutarate levels decrease under hypoxia in control cells, α-ketoglutarate is paradoxically increased under hypoxia when ACC1 or ACLY are depleted. Supplementation with α-ketoglutarate rescued the hypoxia-induced apoptosis and recapitulated the decreased expression and activity of ETV4, likely via an epigenetic mechanism. Therefore, ACC1 and ACLY regulate the levels of ETV4 under hypoxia via increased α-ketoglutarate. These results reveal that the ACC1/ACLY-α-ketoglutarate-ETV4 axis is a novel means by which metabolic states regulate transcriptional output for life vs. death decisions under hypoxia. Since many lipogenic inhibitors are under investigation as cancer therapeutics, our findings suggest that the use of these inhibitors will need to be carefully considered with respect to oncogenic drivers, tumor hypoxia, progression and dormancy. More broadly, our screen provides a framework for studying additional tumor cell stress-adaption mechanisms in the future.

  16. ACLY and ACC1 Regulate Hypoxia-Induced Apoptosis by Modulating ETV4 via α-ketoglutarate

    PubMed Central

    Keenan, Melissa M.; Liu, Beiyu; Tang, Xiaohu; Wu, Jianli; Cyr, Derek; Stevens, Robert D.; Ilkayeva, Olga; Huang, Zhiqing; Tollini, Laura A.; Murphy, Susan K.; Lucas, Joseph; Muoio, Deborah M.; Kim, So Young; Chi, Jen-Tsan

    2015-01-01

    In order to propagate a solid tumor, cancer cells must adapt to and survive under various tumor microenvironment (TME) stresses, such as hypoxia or lactic acidosis. To systematically identify genes that modulate cancer cell survival under stresses, we performed genome-wide shRNA screens under hypoxia or lactic acidosis. We discovered that genetic depletion of acetyl-CoA carboxylase (ACACA or ACC1) or ATP citrate lyase (ACLY) protected cancer cells from hypoxia-induced apoptosis. Additionally, the loss of ACLY or ACC1 reduced levels and activities of the oncogenic transcription factor ETV4. Silencing ETV4 also protected cells from hypoxia-induced apoptosis and led to remarkably similar transcriptional responses as with silenced ACLY or ACC1, including an anti-apoptotic program. Metabolomic analysis found that while α-ketoglutarate levels decrease under hypoxia in control cells, α-ketoglutarate is paradoxically increased under hypoxia when ACC1 or ACLY are depleted. Supplementation with α-ketoglutarate rescued the hypoxia-induced apoptosis and recapitulated the decreased expression and activity of ETV4, likely via an epigenetic mechanism. Therefore, ACC1 and ACLY regulate the levels of ETV4 under hypoxia via increased α-ketoglutarate. These results reveal that the ACC1/ACLY-α-ketoglutarate-ETV4 axis is a novel means by which metabolic states regulate transcriptional output for life vs. death decisions under hypoxia. Since many lipogenic inhibitors are under investigation as cancer therapeutics, our findings suggest that the use of these inhibitors will need to be carefully considered with respect to oncogenic drivers, tumor hypoxia, progression and dormancy. More broadly, our screen provides a framework for studying additional tumor cell stress-adaption mechanisms in the future. PMID:26452058

  17. Influence of storage duration and processing on chromatic attributes and flavonoid content of moxa floss.

    PubMed

    Lim, Min Yee; Huang, Jian; Zhao, Bai-xiao; Zou, Hui-qin; Yan, Yong-hong

    2016-01-01

    Moxibustion is an important traditional Chinese medicine therapy using heat from ignited moxa floss for disease treatment. The purpose of the present study is to establish a reproducible method to assess the color of moxa floss, discriminate the samples based on chromatic coordinates and explore the relationship between chromatic coordinates and total flavonoid content (TFC). Moxa floss samples of different storage years and production ratios were obtained from a moxa production factory in Henan Province, China. Chromatic coordinates (L*, a* and b*) were analyzed with an ultraviolet-visible spectrophotometer and the chroma (C*) and hue angle (h°) values were calculated. TFC was determined by a colorimetric method. Data were analyzed with correlation, principal component analysis (PCA). Significant differences in the chromatic values and TFC were observed among samples of different storage years and production ratios. Samples of higher production ratio displayed higher chromatic characteristics and lower TFC. Samples of longer storage years contained higher TFC. Preliminary separation of moxa floss production ratio was obtained by means of color feature maps developed using L*-a* or L*-b* as coordinates. PCA allowed the separation of the samples from their storage years and production ratios based on their chromatic characteristics and TFC. The use of a colorimetric technique and CIELAB coordinates coupled with chemometrics can be practical and objective for discriminating moxa floss of different storage years and production ratios. The development of color feature maps could be used as a model for classifying the color grading of moxa floss.

  18. Potential US Population Impact of the 2017 ACC/AHA High Blood Pressure Guideline.

    PubMed

    Muntner, Paul; Carey, Robert M; Gidding, Samuel; Jones, Daniel W; Taler, Sandra J; Wright, Jackson T; Whelton, Paul K

    2018-01-09

    The 2017 American College of Cardiology/American Heart Association (ACC/AHA) Guideline for the Prevention, Detection, Evaluation and Management of High Blood Pressure in Adults provides recommendations for the definition of hypertension, systolic and diastolic blood pressure (BP) thresholds for initiation of antihypertensive medication, and BP target goals. This study sought to determine the prevalence of hypertension, implications of recommendations for antihypertensive medication, and prevalence of BP above the treatment goal among US adults using criteria from the 2017 ACC/AHA guideline and the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7). The authors analyzed data from the 2011 to 2014 National Health and Nutrition Examination Survey (N = 9 623). BP was measured 3 times following a standardized protocol and averaged. Results were weighted to produce US population estimates. According to the 2017 ACC/AHA and JNC7 guidelines, the crude prevalence of hypertension among US adults was 45.6% (95% confidence interval [CI]: 43.6% to 47.6%) and 31.9% (95% CI: 30.1% to 33.7%), respectively, and antihypertensive medication was recommended for 36.2% (95% CI: 34.2% to 38.2%) and 34.3% (95% CI: 32.5% to 36.2%) of US adults, respectively. Nonpharmacological intervention is advised for the 9.4% of US adults with hypertension who are not recommended for antihypertensive medication according to the 2017 ACC/AHA guideline. Among US adults taking antihypertensive medication, 53.4% (95% CI: 49.9% to 56.8%) and 39.0% (95% CI: 36.4% to 41.6%) had BP above the treatment goal according to the 2017 ACC/AHA and JNC7 guidelines, respectively. Compared with the JNC7 guideline, the 2017 ACC/AHA guideline results in a substantial increase in the prevalence of hypertension, a small increase in the percentage of US adults recommended for antihypertensive medication, and more intensive BP lowering for many

  19. Self-referenced axial chromatic dispersion measurement in multiphoton microscopy through 2-color THG imaging.

    PubMed

    Du, Yu; Zhuang, Ziwei; He, Jiexing; Liu, Hongji; Qiu, Ping; Wang, Ke

    2018-05-16

    With tunable excitation light, multiphoton microscopy (MPM) is widely used for imaging biological structures at subcellular resolution. Axial chromatic dispersion, present in virtually every transmissive optical system including the multiphoton microscope, leads to focal (and the resultant image) plane separation. Here we demonstrate experimentally a technique to measure the axial chromatic dispersion in a multiphoton microscope, using simultaneous 2-color third-harmonic generation (THG) imaging excited by a 2-color soliton source with tunable wavelength separation. Our technique is self-referenced, eliminating potential measurement error when 1-color tunable excitation light is used which necessitates reciprocating motion of the mechanical translation stage. Using this technique, we demonstrate measured axial chromatic dispersion with 2 different objective lenses in a multiphoton microscope. Further measurement in a biological sample also indicates that this axial chromatic dispersion, in combination with 2-color imaging, may open up opportunity for simultaneous imaging of two different axial planes. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  20. Influence of Magnesium Content on the Local Structure of Amorphous Calcium Carbonate (ACC): Real Time Determination by In Situ PDF Analysis

    NASA Astrophysics Data System (ADS)

    Mergelsberg, S. T.; Ulrich, R. N.; Michel, F. M.; Dove, P. M.

    2016-12-01

    Calcium carbonate minerals are an essential component in the exoskeletons of crustaceans and mollusks. The onset of exoskeleton mineralization includes the precipitation of amorphous calcium carbonate (ACC) as a reactive intermediate that later transforms to produce diverse structures. Despite the importance of ACC as a critical phase during skeleton formation, the chemical and physical properties are not well characterized at conditions that approximate biological environments. Of particular interest are the solubility of ACC, the short-range structure at the time of formation, and the evolution of ACC structure to final products. Recent advances showing the widespread occurrence of multistep pathways to mineralization in biological and geological settings (De Yoreo et al., 2015) underline the importance of understanding amorphous intermediates. Using quantitative laboratory techniques developed by our research group (Blue et al., 2013; Blue and Dove, 2015; Blue et al., in press), this experimental study quantifies the solubility of ACC in parallel with the physical characterization of the corresponding structure. We measured ACC solubility at specific time points during the precipitation and during its subsequent evolution under the mild pH conditions that approximate biological and environmental conditions. In parallel experiments, structural data were collected from in situ pair distribution function (PDF) analyses were conducted to follow the evolution of individual samples from initial precipitation to final product. The measurements are leading to a quantitative solubility function for ACC with variable Mg contents and an x-ray based understanding of ACC structure in the same particles. We are also finding temporal changes in the short-range order of ACC after precipitation and this order is dependent upon Mg content. Moreover, the data show Mg distribution through the ACC particles is dependent upon total alkalinity. Insights from this study hold promise

  1. Objective assessment of chromatic and achromatic pattern adaptation reveals the temporal response properties of different visual pathways.

    PubMed

    Robson, Anthony G; Kulikowski, Janus J

    2012-11-01

    The aim was to investigate the temporal response properties of magnocellular, parvocellular, and koniocellular visual pathways using increment/decrement changes in contrast to elicit visual evoked potentials (VEPs). Static achromatic and isoluminant chromatic gratings were generated on a monitor. Chromatic gratings were modulated along red/green (R/G) or subject-specific tritanopic confusion axes, established using a minimum distinct border criterion. Isoluminance was determined using minimum flicker photometry. Achromatic and chromatic VEPs were recorded to contrast increments and decrements of 0.1 or 0.2 superimposed on the static gratings (masking contrast 0-0.6). Achromatic increment/decrement changes in contrast evoked a percept of apparent motion when the spatial frequency was low; VEPs to such stimuli were positive in polarity and largely unaffected by high levels of static contrast, consistent with transient response mechanisms. VEPs to finer achromatic gratings showed marked attenuation as static contrast was increased. Chromatic VEPs to R/G or tritan chromatic contrast increments were of negative polarity and showed progressive attenuation as static contrast was increased, in keeping with increasing desensitization of the sustained responses of the color-opponent visual pathways. Chromatic contrast decrement VEPs were of positive polarity and less sensitive to pattern adaptation. The relative contribution of sustained/transient mechanisms to achromatic processing is spatial frequency dependent. Chromatic contrast increment VEPs reflect the sustained temporal response properties of parvocellular and koniocellular pathways. Cortical VEPs can provide an objective measure of pattern adaptation and can be used to probe the temporal response characteristics of different visual pathways.

  2. Representation of cardiovascular magnetic resonance in the AHA / ACC guidelines.

    PubMed

    von Knobelsdorff-Brenkenhoff, Florian; Pilz, Guenter; Schulz-Menger, Jeanette

    2017-09-25

    Whereas evidence supporting the diagnostic value of cardiovascular magnetic resonance (CMR) has increased, there exists significant worldwide variability in the clinical utilization of CMR. A recent study demonstrated that CMR is represented in the majority of European Society for Cardiology (ESC) guidelines, with a large number of specific recommendations in particular regarding coronary artery disease. To further investigate the gap between the evidence and clinical use of CMR, this study analyzed the role of CMR in the guidelines of the American College of Cardiology (ACC) and American Heart Association (AHA). Twenty-four AHA/ACC original guidelines, updates and new editions, published between 2006 and 2017, were screened for the terms "magnetic", "MRI", "CMR", "MR" and "imaging". Non-cardiovascular MR examinations were excluded. All CMR-related paragraphs and specific recommendations for CMR including the level of evidence (A, B, C) and the class of recommendation (I, IIa, IIb, III) were extracted. Twelve of the 24 guidelines (50.0%) contain specific recommendations regarding CMR. Four guidelines (16.7%) mention CMR in the text only, and 8 (33.3%) do not mention CMR. The 12 guidelines with recommendations for CMR contain in total 65 specific recommendations (31 class-I, 23 class-IIa, 6 class-IIb, 5 class-III). Most recommendations have evidence level C (44/65; 67.7%), followed by level B (21/65; 32.3%). There are no level A recommendations. 22/65 recommendations refer to vascular imaging, 17 to congenital heart disease, 8 to cardiomyopathies, 8 to myocardial stress testing, 5 to left and right ventricular function, 3 to viability, and 2 to valvular heart disease. CMR is represented in two thirds of the AHA/ACC guidelines, which contain a number of specific recommendations for the use of CMR. In a simplified comparison with the ESC guidelines, CMR is less represented in the AHA/ACC guidelines in particular in the field of coronary artery disease.

  3. Chromatic aberration compensation in numerical reconstruction of digital holograms by Fresnel-Bluestein propagation.

    PubMed

    Hincapie, Diego; Velasquez, Daniel; Garcia-Sucerquia, Jorge

    2017-12-15

    In this Letter, we present a method for chromatic compensation in numerical reconstruction of digitally recorded holograms based on Fresnel-Bluestein propagation. The proposed technique is applied to correct the chromatic aberration that arises in the reconstruction of RGB holograms of both millimeter- and micrometer-sized objects. The results show the feasibility of this strategy to remove the wavelength dependence of the size of the numerically propagated wavefields.

  4. Derivation of Human Chromatic Discrimination Ability from an Information-Theoretical Notion of Distance in Color Space.

    PubMed

    da Fonseca, María; Samengo, Inés

    2016-12-01

    The accuracy with which humans detect chromatic differences varies throughout color space. For example, we are far more precise when discriminating two similar orange stimuli than two similar green stimuli. In order for two colors to be perceived as different, the neurons representing chromatic information must respond differently, and the difference must be larger than the trial-to-trial variability of the response to each separate color. Photoreceptors constitute the first stage in the processing of color information; many more stages are required before humans can consciously report whether two stimuli are perceived as chromatically distinguishable. Therefore, although photoreceptor absorption curves are expected to influence the accuracy of conscious discriminability, there is no reason to believe that they should suffice to explain it. Here we develop information-theoretical tools based on the Fisher metric that demonstrate that photoreceptor absorption properties explain about 87% of the variance of human color discrimination ability, as tested by previous behavioral experiments. In the context of this theory, the bottleneck in chromatic information processing is determined by photoreceptor absorption characteristics. Subsequent encoding stages modify only marginally the chromatic discriminability at the photoreceptor level.

  5. Full-field chromatic confocal surface profilometry employing digital micromirror device correspondence for minimizing lateral cross talks

    NASA Astrophysics Data System (ADS)

    Chen, Liang-Chia; Chang, Yi-Wei; Li, Hau-Wei

    2012-08-01

    Full-field chromatic confocal surface profilometry employing a digital micromirror device (DMD) for spatial correspondence is proposed to minimize lateral cross-talks between individual detection sensors. Although full-field chromatic confocal profilometry is capable of enhancing measurement efficiency by completely removing time-consuming vertical scanning operation, its vertical measurement resolution and accuracy are still severely affected by the potential sensor lateral cross-talk problem. To overcome this critical bottleneck, a DMD-based chromatic confocal method is developed by employing a specially-designed objective for chromatic light dispersion, and a DMD for lateral pixel correspondence and scanning, thereby reducing the lateral cross-talk influence. Using the chromatic objective, the incident light is dispersed according to a pre-designed detection range of several hundred micrometers, and a full-field reflected light is captured by a three-chip color camera for multi color detection. Using this method, the full width half maximum of the depth response curve can be significantly sharpened, thus improving the vertical measurement resolution and repeatability of the depth detection. From our preliminary experimental evaluation, it is verified that the ±3σ repeatability of the height measurement can be kept within 2% of the overall measurement range.

  6. 24 CFR 982.102 - Allocation of budget authority for renewal of expiring consolidated ACC funding increments.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... renewal of expiring consolidated ACC funding increments. 982.102 Section 982.102 Housing and Urban... ASSISTANCE: HOUSING CHOICE VOUCHER PROGRAM Funding and PHA Application for Funding § 982.102 Allocation of budget authority for renewal of expiring consolidated ACC funding increments. (a) Applicability. This...

  7. 24 CFR 982.102 - Allocation of budget authority for renewal of expiring consolidated ACC funding increments.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... renewal of expiring consolidated ACC funding increments. 982.102 Section 982.102 Housing and Urban... ASSISTANCE: HOUSING CHOICE VOUCHER PROGRAM Funding and PHA Application for Funding § 982.102 Allocation of budget authority for renewal of expiring consolidated ACC funding increments. (a) Applicability. This...

  8. 24 CFR 982.102 - Allocation of budget authority for renewal of expiring consolidated ACC funding increments.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... renewal of expiring consolidated ACC funding increments. 982.102 Section 982.102 Housing and Urban... ASSISTANCE: HOUSING CHOICE VOUCHER PROGRAM Funding and PHA Application for Funding § 982.102 Allocation of budget authority for renewal of expiring consolidated ACC funding increments. (a) Applicability. This...

  9. 24 CFR 982.102 - Allocation of budget authority for renewal of expiring consolidated ACC funding increments.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... renewal of expiring consolidated ACC funding increments. 982.102 Section 982.102 Housing and Urban... ASSISTANCE: HOUSING CHOICE VOUCHER PROGRAM Funding and PHA Application for Funding § 982.102 Allocation of budget authority for renewal of expiring consolidated ACC funding increments. (a) Applicability. This...

  10. 24 CFR 982.102 - Allocation of budget authority for renewal of expiring consolidated ACC funding increments.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... renewal of expiring consolidated ACC funding increments. 982.102 Section 982.102 Housing and Urban... ASSISTANCE: HOUSING CHOICE VOUCHER PROGRAM Funding and PHA Application for Funding § 982.102 Allocation of budget authority for renewal of expiring consolidated ACC funding increments. (a) Applicability. This...

  11. Longitudinal chromatic aberration and emmetropization: results from the chicken eye.

    PubMed Central

    Rohrer, B; Schaeffel, F; Zrenner, E

    1992-01-01

    1. Due to the chromatic dispersion of the ocular media, the focal length of the optics of the eye is about 3 diopters longer for red light than for blue light. Because emmetropization in the chicken (Gallus domesticus) does not require colour cues and operates properly in monochromatic light, one can, therefore, expect that chickens raised in red light become more myopic (with longer eyes) than chicks raised in short wavelength light. Prior to conducting this experiment, we matched the brightness of both light conditions by means of flicker electroretinograms such that equiluminance was obtained for the chickens. 2. Unexpectedly, refractive development was not different from controls in white light for either red or near-ultraviolet light. 3. We tested whether the visual mechanisms guiding refractive development were still sensitive to defocus under both illuminations by treating the chicks with spectacle lenses. 4. Similar to a previous experiment in white light, the growth of the eye in red light also changed such that it compensated for the imposed defocus. It failed to do so, however, in near-ultraviolet light. 5. A histological analysis of the sampling intervals for the ultraviolet receptor system revealed that its spatial resolving power was too low to detect the defocus imposed by the lenses, whereas the long wavelength receptors provided sufficiently good visual acuity. 6. The results show that, during emmetropization, the chicken eye elegantly bypasses the problem of multiple chromatic focal planes by having a low sensitivity to defocus in the blue end of the spectrum. Because the chromatic dispersion function is steep in the blue range but flat at the red end of the spectrum, the remaining chromatic defocus in the spectral range of high visual acuity is low and may match the depth of field of the eye. PMID:1522513

  12. The MOF+ Technique: A Significant Synergic Effect Enables High Performance Chromate Removal.

    PubMed

    Luo, Ming Biao; Xiong, Yang Yang; Wu, Hui Qiong; Feng, Xue Feng; Li, Jian Qiang; Luo, Feng

    2017-12-18

    A significant synergic effect between a metal-organic framework (MOF) and Fe 2 SO 4 , the so-called MOF + technique, is exploited for the first time to remove toxic chromate from aqueous solutions. The results show that relative to the pristine MOF samples (no detectable chromate removal), the MOF + method enables super performance, giving a 796 Cr mg g -1 adsorption capacity. The value is almost eight-fold higher than the best value of established MOF adsorbents, and the highest value of all reported porous adsorbents for such use. The adsorption mechanism, unlike the anion-exchange process that dominates chromate removal in all other MOF adsorbents, as unveiled by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), is due to the surface formation of Fe 0.75 Cr 0.25 (OH) 3 nanospheres on the MOF samples. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Exploiting chromatic aberration to spectrally encode depth in reflectance confocal microscopy

    NASA Astrophysics Data System (ADS)

    Carrasco-Zevallos, Oscar; Shelton, Ryan L.; Olsovsky, Cory; Saldua, Meagan; Applegate, Brian E.; Maitland, Kristen C.

    2011-06-01

    We present chromatic confocal microscopy as a technique to axially scan the sample by spectrally encoding depth information to avoid mechanical scanning of the lens or sample. We have achieved an 800 μm focal shift over a range of 680-1080 nm using a hyperchromat lens as the imaging lens. A more complex system that incorporates a water immersion objective to improve axial resolution was built and tested. We determined that increasing objective magnification decreases chromatic shift while improving axial resolution. Furthermore, collimating after the hyperchromat at longer wavelengths yields an increase in focal shift.

  14. ACCE/ACS National Educator and Leader of the Year Winners: AEC Congratulates These Outstanding Educators

    ERIC Educational Resources Information Center

    Australian Educational Computing, 2012

    2012-01-01

    This article presents the ACCE/ACS National Educator and Leader of the Year winners. Anne Mirtschin is the recipient of the ACCE/ACS 2012 Educator of the Year Award. Mirtschin is an innovative teacher at Hawkesdale P-12 College a small rural school that is isolated culturally and geographically. She uses online tools and technology to create…

  15. Simultaneous determination of zinc and chromate in cooling water by differential pulse polarography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jindal, V.K.; Kham, M.A.; Bhatnagar, R.M.

    1985-01-01

    The use of differential pulse polarography (DPP) for the simultaneous determination of zinc and chromate in cooling water is reported where zinc (5 ppm), chromate (20 ppm), and polyphosphate (50 ppm) formulation is used as a corrosion inhibitor. This will help in effective control of cooling tower performance. The DPP method has been applied for the simultaneous determination of zinc and chromate ions in process and cooling water samples from fertilizer plants in India. The method is based on the reduction of Cr and Zn on SMDE in 1 M NH3-0.1 M NH/sub 4/Cl and 0.005% gelatine supporting electrolyte. Duemore » to interference it is essential to complex calcium ions by adding polyphosphate and to destroy NO/sub 2//sup -//NO/sub 3//sup -/ by adding sulfamic acid along with hydrochloric acid before the actual recording of DP polarograms. The present DP polarographic method for the simultaneous determination of zinc and chromate is comparable in its utility and applicability with spectrophotometric methods. The method has a better accuracy and higher sensitivity and is quick, as both of the ions can be determined in a single scan. 10 references, 4 figures, 5 tables.« less

  16. Chromatic discrimination: differential contributions from two adapting fields

    PubMed Central

    Cao, Dingcai; Lu, Yolanda H.

    2012-01-01

    To test whether a retinal or cortical mechanism sums contributions from two adapting fields to chromatic discrimination, L/M discrimination was measured with a test annulus surrounded by an inner circular field and an outer rectangular field. A retinal summation mechanism predicted that the discrimination pattern would not change with a change in the fixation location. Therefore, the fixation was set either in the inner or the outer field in two experiments. When one of the adapting fields was “red” and the other was “green,” the adapting field where the observer fixated always had a stronger influence on chromatic discrimination. However, when one adapting field was “white” and the other was red or green, the white field always weighted more heavily than the other adapting field in determining discrimination thresholds, whether the white field or the fixation was in the inner or outer adapting field. These results suggest that a cortical mechanism determines the relative contributions from different adapting fields. PMID:22330364

  17. Chromatic discrimination: differential contributions from two adapting fields.

    PubMed

    Cao, Dingcai; Lu, Yolanda H

    2012-02-01

    To test whether a retinal or cortical mechanism sums contributions from two adapting fields to chromatic discrimination, L/M discrimination was measured with a test annulus surrounded by an inner circular field and an outer rectangular field. A retinal summation mechanism predicted that the discrimination pattern would not change with a change in the fixation location. Therefore, the fixation was set either in the inner or the outer field in two experiments. When one of the adapting fields was "red" and the other was "green," the adapting field where the observer fixated always had a stronger influence on chromatic discrimination. However, when one adapting field was "white" and the other was red or green, the white field always weighted more heavily than the other adapting field in determining discrimination thresholds, whether the white field or the fixation was in the inner or outer adapting field. These results suggest that a cortical mechanism determines the relative contributions from different adapting fields. © 2012 Optical Society of America

  18. Development of an EMG-ACC-Based Upper Limb Rehabilitation Training System.

    PubMed

    Ling Liu; Xiang Chen; Zhiyuan Lu; Shuai Cao; De Wu; Xu Zhang

    2017-03-01

    This paper focuses on the development of an upper limb rehabilitation training system designed for use by children with cerebral palsy (CP). It attempts to meet the requirements of in-home training by taking advantage of the combination of portable accelerometers (ACC) and surface electromyography (SEMG) sensors worn on the upper limb to capture functional movements. In the proposed system, the EMG-ACC acquisition device works essentially as wireless game controller, and three rehabilitation games were designed for improving upper limb motor function under a clinician's guidance. The games were developed on the Android platform based on a physical engine called Box2D. The results of a system performance test demonstrated that the developed games can respond to the upper limb actions within 210 ms. Positive questionnaire feedbacks from twenty CP subjects who participated in the game test verified both the feasibility and usability of the system. Results of a long-term game training conducted with three CP subjects demonstrated that CP patients could improve in their game performance through repetitive training, and persistent training was needed to improve and enhance the rehabilitation effect. According to our experimental results, the novel multi-feedback SEMG-ACC-based user interface improved the users' initiative and performance in rehabilitation training.

  19. Developmental characterization and environmental stress responses of Y-box binding protein 1 gene (AccYB-1) from Apis cerana cerana.

    PubMed

    Li, Guilin; Wang, Lijun; Wang, Ying; Li, Han; Liu, Zhenguo; Wang, Hongfang; Xu, Baohua; Guo, Xingqi

    2018-06-22

    Y-box binding protein 1 (YB-1) is a member of the cold shock domain protein superfamily and is involved in development, environmental stresses and DNA oxidative damage in many organisms. However, the precise functions of YB-1 are still not well understood in various insects, including bees. In the current study, we identified a YB-1 gene in Apis cerana cerana (AccYB-1). The predicted cis-acting elements in the promoter sequence of AccYB-1 indicated its possible roles in development and stress responses. AccYB-1 expression was higher in one-day-old larvae and dark-eyed pupae than in other development stages. Tissue-specific expression analysis showed that the mRNA level of AccYB-1 was higher in the thorax and midgut than in other tissues. The results from real-time PCR showed that AccYB-1 was induced by many environmental stresses. Silencing AccYB-1 downregulated the transcriptional level of some growth- and development-related genes and antioxidant genes and decreased the enzyme activities of several antioxidant-related enzymes, further indicating a possible function of AccYB-1 in growth, development and stress responses. Taken together, our findings suggest that AccYB-1 may play an indispensable role in growth and development and environmental stress responses in Apis cerana cerana. To our knowledge, this is the first paper to explore the role of YB-1 in bees. Copyright © 2018. Published by Elsevier B.V.

  20. AccR Is a Master Regulator Involved in Carbon Catabolite Repression of the Anaerobic Catabolism of Aromatic Compounds in Azoarcus sp. CIB*

    PubMed Central

    Valderrama, J. Andrés; Shingler, Victoria; Carmona, Manuel; Díaz, Eduardo

    2014-01-01

    Here we characterized the first known transcriptional regulator that accounts for carbon catabolite repression (CCR) control of the anaerobic catabolism of aromatic compounds in bacteria. The AccR response regulator of Azoarcus sp. CIB controls succinate-responsive CCR of the central pathways for the anaerobic catabolism of aromatics by this strain. Phosphorylation of AccR to AccR-P triggers a monomer-to-dimer transition as well as the ability to bind to the target promoter and causes repression both in vivo and in vitro. Substitution of the Asp60 phosphorylation target residue of the N-terminal receiver motif of AccR to a phosphomimic Glu residue generates a constitutively active derivative that behaves as a superrepressor of the target genes. AccR-P binds in vitro to a conserved inverted repeat (ATGCA-N6-TGCAT) present at two different locations within the PN promoter of the bzd genes for anaerobic benzoate degradation. Because the DNA binding-proficient C-terminal domain of AccR is monomeric, we propose an activation mechanism in which phosphorylation of Asp60 of AccR alleviates interdomain repression mediated by the N-terminal domain. The presence of AccR-like proteins encoded in the genomes of other β-proteobacteria of the Azoarcus/Thauera group further suggests that AccR constitutes a master regulator that controls anaerobic CCR in these bacteria. PMID:24302740

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  3. Effects of intraocular lenses with different diopters on chromatic aberrations in human eye models.

    PubMed

    Song, Hui; Yuan, Xiaoyong; Tang, Xin

    2016-01-11

    In this study, the effects of intraocular lenses (IOLs) with different diopters (D) on chromatic aberration were investigated in human eye models, and the influences of the central thickness of IOLs on chromatic aberration were compared. A Liou-Brennan-based IOL eye model was constructed using ZEMAX optical design software. Spherical IOLs with different diopters (AR40e, AMO Company, USA) were implanted; modulation transfer function (MTF) values at 3 mm of pupil diameter and from 0 to out-of-focus blur were collected and graphed. MTF values, measured at 555 nm of monochromatic light under each spatial frequency, were significantly higher than the values measured at 470 to 650 nm of polychromatic light. The influences of chromatic aberration on MTF values decreased with the increase in IOL diopter when the spatial frequency was ≤12 c/d, while increased effects were observed when the spatial frequency was ≥15 c/d. The MTF values of each IOL eye model were significantly lower than the MTF values of the Liou-Brennan eye models when measured at 555 nm of monochromatic light and at 470 to 650 nm of polychromatic light. The MTF values were also found to be increased with the increase in IOL diopter. With higher diopters of IOLs, the central thickness increased accordingly, which could have created increased chromatic aberration and decreased the retinal image quality. To improve the postoperative visual quality, IOLs with lower chromatic aberration should be selected for patients with short axial lengths.

  4. Accelerated Corrosion Results for Zinc/Nickel-Plated Automotive Parts Posttreated With Trivalent Chromate Rinse

    DTIC Science & Technology

    2010-09-01

    400 and 300 h in neutral salt spray. 5 Similarly plated samples post treated with trivalent chromium rinse lasted 450 and 200 h in neutral salt...Accelerated Corrosion Results for Zinc/Nickel-Plated Automotive Parts Posttreated With Trivalent Chromate Rinse by Chris E. Miller, Brian E...Posttreated With Trivalent Chromate Rinse Chris E. Miller and Brian E. Placzankis Weapons and Materials Research Directorate, ARL I. Carl Handsy

  5. Chronic exposure to particulate chromate induces spindle assembly checkpoint bypass in human lung cells.

    PubMed

    Wise, Sandra S; Holmes, Amie L; Xie, Hong; Thompson, W Douglas; Wise, John Pierce

    2006-11-01

    One of the hallmarks of lung cancer is chromosome instability (CIN), particularly a tetraploid phenotype, which is normally prevented by the spindle assembly checkpoint. Hexavalent chromium Cr(VI) is an established human lung carcinogen, and Cr(VI) induces tumors at lung bifurcation sites where Cr(VI) particles impact and persist. However, the effects of Cr(VI) on the spindle assembly checkpoint are unknown and little is known about prolonged exposure to particulate Cr(VI). Accordingly, we investigated particulate Cr(VI)-induced bypass of the spindle assembly checkpoint after several days of exposure in WHTBF-6 cells. We found that lead chromate indeed induces spindle assembly checkpoint bypass in human lung cells, as 72, 96, and 120 h treatments with 0.5 or 1 microg/cm2 lead chromate induced significant increases in the percentage of cells with aberrant mitotic figures. For example, treatment with 1 microg/cm2 lead chromate for 96 h induced 11, 12.3, and 14% of cells with premature anaphase, centromere spreading and premature centromere division, respectively. In addition, we found a disruption of mitosis with more cells accumulating in anaphase; cells treated for 96 h increased from 18% in controls to 31% in cells treated with lead chromate. To confirm involvement of the spindle assembly checkpoint, Mad2 expression was used as a marker. Mad2 expression was decreased in cells exposed to chronic treatments of lead chromate, consistent with disruption of the checkpoint. We also found concentration- and time-dependent increases in tetraploid cells, which continued to grow and form colonies. When cells were treated with chronic lead alone there was no increase in aberrant mitotic cells or polyploidy; however, chronic exposure to a soluble Cr(VI) showed an increase in aberrant mitotic cells and polyploidy. These data suggest that lead chromate does induce CIN and may be one mechanism in the development of Cr(VI)-induced lung cancer.

  6. Calculating Correlated Color Temperatures Across the Entire Gamut of Daylight and Skylight Chromaticities

    DTIC Science & Technology

    1999-09-20

    c o i b f t c c c c w n c s p t s Calculating correlated color temperatures across the entire gamut of daylight and skylight chromaticities Javier...temperature ~CCT!, yet existing equations for calculating CCT from chromaticity coordinates span only part of this range. To improve both the gamut and accuracy...00-1999 to 00-00-1999 4. TITLE AND SUBTITLE Calculating correlated color temperatures across the entire gamut of daylight and skylight

  7. Chromatic Titanium Photoanode for Dye-Sensitized Solar Cells under Rear Illumination.

    PubMed

    Huang, Chih-Hsiang; Chen, Yu-Wen; Chen, Chih-Ming

    2018-01-24

    Titanium (Ti) has high potential in many practical applications such as biomedicine, architecture, aviation, and energy. In this study, we demonstrate an innovative application of dye-sensitized solar cells (DSSCs) based on Ti photoanodes that can be integrated into the roof engineering of large-scale architectures. A chromatic Ti foil produced by anodizing oxidation (coloring) technology is an attractive roof material for large-scale architecture, showing a colorful appearance due to the formation of a reflective TiO 2 thin layer on both surfaces of Ti. The DSSC is fabricated on the backside of the chromatic Ti foil using the Ti foil as the working electrode, and this roof-DSSC hybrid configuration can be designed as an energy harvesting device for indoor artificial lighting. Our results show that the facet-textured TiO 2 layer on the chromatic Ti foil not only improves the optical reflectance for better light utilization but also effectively suppresses the charge recombination for better electron collection. The power conversion efficiency of the roof-DSSC hybrid system is improved by 30-40% with a main contribution from an improvement of short-circuit current density under standard 1 sun and dim-light (600-1000 lx) illumination.

  8. Design of measurement system of 3D surface profile based on chromatic confocal technology

    NASA Astrophysics Data System (ADS)

    Wang, An-su; Xie, Bin; Liu, Zi-wei

    2018-01-01

    Chromatic confocal 3D profilometer has widely used in science investigation and industry fields recently for its high precision, great measuring range and numerical surface characteristic. It can provide exact and omnidirectional solution for manufacture and research by 3D non-contact surface analysis technique. The article analyzes the principle of surface measurement with chromatic confocal technology, and provides the designing indicators and requirements of the confocal system. As the key component, the dispersive objective used to achieve longitudinal focus vibration with wavelength was designed. The objective disperses the focus of wavelength between 400 700 nm to 15 mm longitudinal range. With selected spectrometer, the resolution of chromatic confocal 3D profilometer is no more than 5 μm, which can meet needs for the high precision non-contact surface profile measurement.

  9. Chromatic aberration of light focusing in hyperbolic anisotropic metamaterial made of metallic slit array.

    PubMed

    Guo, Kai; Liu, Jianlong; Zhang, Yan; Liu, Shutian

    2012-12-17

    The dispersion of a hyperbolic anisotropic metamaterial (HAM) and the chromatic aberration of light focusing in this kind of HAM are studied. The HAM is formed by alternately stacking metal and dielectric layers. The rules of materials and filling factors affecting the optical property of HAM are given. The chromatic aberration of light focusing is demonstrated both theoretically and numerically. By comparing the theory with the simulation results, the factors influencing the focal length, including the heat loss of material and low spatial frequency modes, are discussed. The investigation emphasizes the anomalous properties, such as chromatic aberration and low spatial frequency modes influencing focus position, of HAM compared with that in conventional lens. Based on the analysis, the possibility of using HAM to focus light with two different wavelengths at the same point is studied.

  10. Engineered ACC deaminase-expressing free-living cells of Mesorhizobium loti show increased nodulation efficiency and competitiveness on Lotus spp.

    PubMed

    Conforte, Valeria P; Echeverria, Mariela; Sánchez, Cintia; Ugalde, Rodolfo A; Menéndez, Ana B; Lepek, Viviana C

    2010-08-01

    Ethylene inhibits the establishment of symbiosis between rhizobia and legumes. Several rhizobia species express the enzyme ACC deaminase, which degrades the ethylene precursor 1-cyclopropane-1-carboxilate (ACC), leading to reductions in the amount of ethylene evolved by the plant. M. loti has a gene encoding ACC deaminase, but this gene is under the activity of the NifA-RpoN-dependent promoter; thus, it is only expressed inside the nodule. The M. loti structural gene ACC deaminase (acdS) was integrated into the M. loti chromosome under a constitutive promoter activity. The resulting strain induced the formation of a higher number of nodules and was more competitive than the wild-type strain on Lotus japonicus and L. tenuis. These results suggest that the introduction of the ACC deaminase activity within M. loti in a constitutive way could be a novel strategy to increase nodulation competitiveness of the bacteria, which could be useful for the forage inoculants industry.

  11. Establishing the solubility and local structure(s) of Amorphous Calcium Carbonate (ACC): Toward an understanding of invertebrate biomineralization

    NASA Astrophysics Data System (ADS)

    Mergelsberg, S. T.; Ulrich, R. N.; Michel, F. M.; Dove, P. M.

    2017-12-01

    Recent advances in high-resolution imaging show the widespreadd occurrence of multistep pathways to mineralization in biological and geological settings (De Yoreo et al., 2015, Science). For example, carbonate biomineralization often involves precipitation of amorphous calcium carbonate (ACC) as a reactive intermediate that subsequently transforms to crystalline products with diverse structures. Although current carbonate mineral proxies are based upon the composition of final crystalline products, the final signatures may be recording the properties of the initial amorphous phase. Thus, it is critical to establish the physical properties of ACC and understand the factors that influence its evolution to final products at conditions that approximate biological environments. This disconnect limits our ability to build a process-based understanding of when/how minor and trace elements are recorded in mineral composition proxies. In this experimental study, we quantified the chemical and physical properties of ACC and its evolution to final products. We first determined ACC solubility under controlled chemical conditions using a new type of flow-through reactor developed by our research group (Blue and Dove, 2015, GCA; Blue et al., 2017, GCA). The experimental design varied Mg concentration and total alkalinity while maintaining a mild pH that approximates biological environments. ACC solubility was measured at specific time points during the precipitation (from super- and undersaturated conditions) and during its subsequent evolution. Parallel experiments characterized the structure of the corresponding amorphous products using in situ pair distribution function (PDF) and small-angle x-ray scattering (SAXS) analyses. The measurements demonstrate at least two types of ACC can be produced by tuning Mg concentration and alkalinity. Each "phase" exhibits distinct short-range ordering that demonstrates structure-specific solubility. We also find temporal changes in the

  12. Chromaticity and color saturation of ultraviolet irradiated poly(vinyl alcohol)-anthocyanin coatings

    NASA Astrophysics Data System (ADS)

    Mat Nor, N. A.; Aziz, N.; Mohd-Adnan, A. F.; Taha, R. M.; Arof, A. K.

    2016-06-01

    The purpose of this paper is to evaluate the chromaticity and color saturation of anthocyanin extraction from fruit pericarps of Ixora siamensis in a poly(vinyl alcohol) (PVA) matrix. The colored PVA matrix was exposed to UV-B irradiation for 93 days at UV intensity of 17.55 lux. Anthocyanin colorant has been extracted using methanol acidified with 0.5% trifluoroacetic acid (TFA). Different concentrations of ferulic acid (FA) (0, 1, 2, 3, 4 and 5 wt.%) have been added to the anthocyanin extractions before mixing with PVA to form a coating system. The PVA-anthocyanin-FA mixtures have been coated on glass slides and kept overnight in the dark for curing before exposure to UV-B irradiation. The FA-free sample undergoes more color degradation compared to samples containing FA. The coating with 2% FA has the most stable color with chromaticity of 41% and color saturation of 0.88 compared to other FA containing coats. The FA-free coat exhibits 29% chromaticity and color saturation of 0.38 at the end of the experiment.

  13. Copper-resistant bacteria enhance plant growth and copper phytoextraction.

    PubMed

    Yang, Renxiu; Luo, Chunling; Chen, Yahua; Wang, Guiping; Xu, Yue; Shen, Zhenguo

    2013-01-01

    In this study, we investigated the role of rhizospheric bacteria in solubilizing soil copper (Cu) and promoting plant growth. The Cu-resistant bacterium DGS6 was isolated from a natural Cu-contaminated soil and was identified as Pseudomonas sp. DGS6. This isolate solubilized Cu in Cu-contaminated soil and stimulated root elongation of maize and sunflower. Maize was more sensitive to inoculation with DGS6 than was sunflower and exhibited greater root elongation. In pot experiment, inoculation with DGS6 increased the shoot dry weight of maize by 49% and sunflower by 34%, and increased the root dry weight of maize by 85% and sunflower by 45%. Although the concentrations of Cu in inoculated and non-inoculated seedlings did not differ significantly, the total accumulation of Cu in the plants increased after inoculation. DGS6 showed a high ability to solubilize P and produce iron-chelating siderophores, as well as significantly improved the accumulation of P and Fe in both maize and sunflower shoots. In addition, DGS6 produced indole-3-acetic acid (IAA) and ACC deaminase, which suggests that it may modulate ethylene levels in plants. The bacterial strain DGS6 could be a good candidate for re-vegetation of Cu-contaminated sites. Supplemental materials are available for this article. Go to the publisher's online edition of International Journal of Phytoremediation to view the supplemental file.

  14. Portable multi-node LQCD Monte Carlo simulations using OpenACC

    NASA Astrophysics Data System (ADS)

    Bonati, Claudio; Calore, Enrico; D'Elia, Massimo; Mesiti, Michele; Negro, Francesco; Sanfilippo, Francesco; Schifano, Sebastiano Fabio; Silvi, Giorgio; Tripiccione, Raffaele

    This paper describes a state-of-the-art parallel Lattice QCD Monte Carlo code for staggered fermions, purposely designed to be portable across different computer architectures, including GPUs and commodity CPUs. Portability is achieved using the OpenACC parallel programming model, used to develop a code that can be compiled for several processor architectures. The paper focuses on parallelization on multiple computing nodes using OpenACC to manage parallelism within the node, and OpenMPI to manage parallelism among the nodes. We first discuss the available strategies to be adopted to maximize performances, we then describe selected relevant details of the code, and finally measure the level of performance and scaling-performance that we are able to achieve. The work focuses mainly on GPUs, which offer a significantly high level of performances for this application, but also compares with results measured on other processors.

  15. Chromatic energy filter and characterization of laser-accelerated proton beams for particle therapy

    NASA Astrophysics Data System (ADS)

    Hofmann, Ingo; Meyer-ter-Vehn, Jürgen; Yan, Xueqing; Al-Omari, Husam

    2012-07-01

    The application of laser accelerated protons or ions for particle therapy has to cope with relatively large energy and angular spreads as well as possibly significant random fluctuations. We suggest a method for combined focusing and energy selection, which is an effective alternative to the commonly considered dispersive energy selection by magnetic dipoles. Our method is based on the chromatic effect of a magnetic solenoid (or any other energy dependent focusing device) in combination with an aperture to select a certain energy width defined by the aperture radius. It is applied to an initial 6D phase space distribution of protons following the simulation output from a Radiation Pressure Acceleration model. Analytical formula for the selection aperture and chromatic emittance are confirmed by simulation results using the TRACEWIN code. The energy selection is supported by properly placed scattering targets to remove the imprint of the chromatic effect on the beam and to enable well-controlled and shot-to-shot reproducible energy and transverse density profiles.

  16. Spatial and temporal aspects of chromatic adaptation and their functional significance for colour constancy.

    PubMed

    Werner, Annette

    2014-11-01

    Illumination in natural scenes changes at multiple temporal and spatial scales: slow changes in global illumination occur in the course of a day, and we encounter fast and localised illumination changes when visually exploring the non-uniform light field of three-dimensional scenes; in addition, very long-term chromatic variations may come from the environment, like for example seasonal changes. In this context, I consider the temporal and spatial properties of chromatic adaptation and discuss their functional significance for colour constancy in three-dimensional scenes. A process of fast spatial tuning in chromatic adaptation is proposed as a possible sensory mechanism for linking colour constancy to the spatial structure of a scene. The observed middlewavelength selectivity of this process is particularly suitable for adaptation to the mean chromaticity and the compensation of interreflections in natural scenes. Two types of sensory colour constancy are distinguished, based on the functional differences of their temporal and spatial scales: a slow type, operating at a global scale for the compensation of the ambient illumination; and a fast colour constancy, which is locally restricted and well suited to compensate region-specific variations in the light field of three dimensional scenes. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Report of the Annual Scientific Session of the American College of Cardiology (ACC) 2018, Orlando.

    PubMed

    Hashimoto, Takuya; Ako, Junya

    2018-04-28

    The 67 th Annual Scientific Session and Expo of the American College of Cardiology (ACC) were held at the Orange County Convention Center, Orlando, from March 10-12, 2018. This meeting offered 2,700 accepted abstracts presented in oral and poster sessions by 2,100 experts and 37 Late-Breaking Clinical Trials and Featured Clinical Research presentations. This report introduces the key presentations and highlights from the ACC 2018 Scientific Session.

  18. Meta-Transcriptomic Analysis of a Chromate-Reducing Aquifer Microbial Community

    NASA Astrophysics Data System (ADS)

    Beller, H. R.; Brodie, E. L.; Han, R.; Karaoz, U.

    2010-12-01

    A major challenge for microbial ecology that has become more tractable in the advent of new molecular techniques is characterizing gene expression in complex microbial communities. We are using meta-transcriptomic analysis to characterize functional changes in an aquifer-derived, chromate-reducing microbial community as it transitions through various electron-accepting conditions. We inoculated anaerobic microcosms with groundwater from the Cr-contaminated Hanford 100H site and supplemented them with lactate and electron acceptors present at the site, namely, nitrate, sulfate, and Fe(III). The microcosms progressed successively through various electron-accepting conditions (e.g., denitrifying, sulfate-reducing, and ferric iron-reducing conditions, as well as nitrate-dependent, chemolithotrophic Fe(II)-oxidizing conditions). Cr(VI) was rapidly reduced initially and again upon further Cr(VI) amendments. Extensive geochemical sampling and analysis (e.g., lactate, acetate, chloride, nitrate, nitrite, sulfate, dissolved Cr(VI), total Fe(II)), RNA/DNA harvesting, and PhyloChip analyses were conducted. Methods were developed for removal of rRNA from total RNA in preparation for meta-transcriptome sequencing. To date, samples representing denitrifying and fermentative/sulfate-reducing conditions have been sequenced using 454 Titanium technology. Of the non-rRNA related reads for the denitrifying sample (which was also actively reducing chromate), ca. 8% were associated with denitrification and ca. 0.9% were associated with chromate resistance/transport, in contrast to the fermentative/sulfate-reducing sample (in which chromate had already been reduced), which had zero reads associated with either of these categories but many predicted proteins associated with sulfate-reducing bacteria. We observed sequences for key functional transcripts that were unique at the nucleotide level compared to the GenBank non-redundant database [such as L-lactate dehydrogenase (iron

  19. Chromatic refraction with global ozone monitoring by occultation of stars. I. Description and scintillation correction.

    PubMed

    Dalaudier, F; Kan, V; Gurvich, A S

    2001-02-20

    We describe refractive and chromatic effects, both regular and random, that occur during star occultations by the Earth's atmosphere. The scintillation that results from random density fluctuations, as well as the consequences of regular chromatic refraction, is qualitatively described. The resultant chromatic scintillation will produce random features on the Global Ozone Monitoring by Occultation of Stars (GOMOS) spectrometer, with an amplitude comparable with that of some of the real absorbing features that result from atmospheric constituents. A correction method that is based on the use of fast photometer signals is described, and its efficiency is discussed. We give a qualitative (although accurate) description of the phenomena, including numerical values when needed. Geometrical optics and the phase-screen approximation are used to keep the description simple.

  20. [A Method for Selecting Self-Adoptive Chromaticity of the Projected Markers].

    PubMed

    Zhao, Shou-bo; Zhang, Fu-min; Qu, Xing-hua; Zheng, Shi-wei; Chen, Zhe

    2015-04-01

    The authors designed a self-adaptive projection system which is composed of color camera, projector and PC. In detail, digital micro-mirror device (DMD) as a spatial light modulator for the projector was introduced in the optical path to modulate the illuminant spectrum based on red, green and blue light emitting diodes (LED). However, the color visibility of active markers is affected by the screen which has unknown reflective spectrum as well. Here active markers are projected spot array. And chromaticity feature of markers is sometimes submerged in similar spectral screen. In order to enhance the color visibility of active markers relative to screen, a method for selecting self-adaptive chromaticity of the projected markers in 3D scanning metrology is described. Color camera with 3 channels limits the accuracy of device characterization. For achieving interconversion of device-independent color space and device-dependent color space, high-dimensional linear model of reflective spectrum was built. Prior training samples provide additional constraints to yield high-dimensional linear model with more than three degrees of freedom. Meanwhile, spectral power distribution of ambient light was estimated. Subsequently, markers' chromaticity in CIE color spaces was selected via maximization principle of Euclidean distance. The setting values of RGB were easily estimated via inverse transform. Finally, we implemented a typical experiment to show the performance of the proposed approach. An 24 Munsell Color Checker was used as projective screen. Color difference in the chromaticity coordinates between the active marker and the color patch was utilized to evaluate the color visibility of active markers relative to the screen. The result comparison between self-adaptive projection system and traditional diode-laser light projector was listed and discussed to highlight advantage of our proposed method.

  1. Detailed spatiotemporal brain mapping of chromatic vision combining high-resolution VEP with fMRI and retinotopy.

    PubMed

    Pitzalis, Sabrina; Strappini, Francesca; Bultrini, Alessandro; Di Russo, Francesco

    2018-03-13

    Neuroimaging studies have identified so far, several color-sensitive visual areas in the human brain, and the temporal dynamics of these activities have been separately investigated using the visual-evoked potentials (VEPs). In the present study, we combined electrophysiological and neuroimaging methods to determine a detailed spatiotemporal profile of chromatic VEP and to localize its neural generators. The accuracy of the present co-registration study was obtained by combining standard fMRI data with retinotopic and motion mapping data at the individual level. We found a sequence of occipito activities more complex than that typically reported for chromatic VEPs, including feed-forward and reentrant feedback. Results showed that chromatic human perception arises by the combined activity of at the least five parieto-occipital areas including V1, LOC, V8/VO, and the motion-sensitive dorsal region MT+. However, the contribution of V1 and V8/VO seems dominant because the re-entrant activity in these areas was present more than once (twice in V8/VO and thrice in V1). This feedforward and feedback chromatic processing appears delayed compared with the luminance processing. Associating VEPs and neuroimaging measures, we showed for the first time a complex spatiotemporal pattern of activity, confirming that chromatic stimuli produce intricate interactions of many different brain dorsal and ventral areas. © 2018 Wiley Periodicals, Inc.

  2. Chromatic effect in a novel THz generation scheme

    NASA Astrophysics Data System (ADS)

    Li, Bin; Zhang, Wenyan; Liu, Xiaoqing; Deng, Haixiao; Lan, Taihe; Liu, Bo; Liu, Jia; Wang, Xingtao; Zeng, Zhinan; Zhang, Lijian

    2017-11-01

    Deriving single or few cycle terahertz (THz) pulse by an intense femtosecond laser through cascaded optical rectification is a crucial technique in cutting-edge time-resolved spectroscopy to characterize micro-scale structures and ultrafast dynamics. Due to the broadband nature of the ultrafast driving laser, the chromatic effect limits the THz conversion efficiency in optical rectification crystals, especially for those implementing the pulse-front tilt scheme, e.g. lithium niobate (LN) crystal, has been prevalently used in the past decade. In this research we developed a brand new type of LN crystal utilizing Brewster coupling, and conducted systematically experimental and simulative investigation for the chromatic effect and multi-dimensionally entangled parameters in THz generation, predicting that an extreme conversion efficiency of ˜10% would be potentially achievable at the THz absorption coefficient of ˜0.5 cm-1. Moreover, we first discovered that the chirp of the driving laser plays a decisive role in the pulse-front tilt scheme, and the THz generation efficiency could be enhanced tremendously by applying an appropriate chirp.

  3. Informational primacy of visual dimensions: specialized roles for luminance and chromaticity in figure-ground perception.

    PubMed

    Yamagishi, N; Melara, R D

    2001-07-01

    Three experiments were conducted to examine the distinct contributions of two visual dimensions to figure-ground segregation. In each experiment, pattern identification was assessed by asking observers to judge whether a near-threshold test pattern was the same or different in shape to a high-contrast comparison pattern. A test pattern could differ from its background along one dimension, either luminance (luminance tasks) or chromaticity (chromaticity tasks). In each task, performance in a baseline condition, in which the test pattern was intact, was compared with performance in each of several degradation conditions, in which either the contour or the surface of the figure was degraded, using either partial occlusion (Experiment 1) or ramping (Experiments 2 and 3) of figure-ground differences. In each experiment, performance in luminance tasks was worst when the contour was degraded, whereas performance in chromaticity tasks was worst when the surface was degraded. This interaction was found even when spatial frequencies were fixed across test patterns by low-pass filtering. The results are consistent with a late (postfiltering) dual-mechanism system that processes luminance information to extract boundary representations and chromaticity information to extract surface representations.

  4. The ACCE 2012 Study Tour: Reflections on Reoccurring Themes

    ERIC Educational Resources Information Center

    Clements, Di; Grover, David; Grover, Pam; Hearne, Dominic; Knipe, Steven; Martin, Kim; Pazzi, Georgina; Pollard, Edward; Prestridge, Sarah

    2012-01-01

    Transformational leadership is essential in education as it empowers educators to make positive changes to the way they think, feel and act in improving learning for all. Reflection is a vital element of leading the change process. In relation to participating in the ACCE study tour experience, reflection allows one to sit and think about the…

  5. Molecular Characterization of Lactobacillus plantarum Genes for β-Ketoacyl-Acyl Carrier Protein Synthase III (fabH) and Acetyl Coenzyme A Carboxylase (accBCDA), Which Are Essential for Fatty Acid Biosynthesis

    PubMed Central

    Kiatpapan, Pornpimon; Kobayashi, Hajime; Sakaguchi, Maki; Ono, Hisayo; Yamashita, Mitsuo; Kaneko, Yoshinobu; Murooka, Yoshikatsu

    2001-01-01

    Genes for subunits of acetyl coenzyme A carboxylase (ACC), which is the enzyme that catalyzes the first step in the synthesis of fatty acids in Lactobacillus plantarum L137, were cloned and characterized. We identified six potential open reading frames, namely, manB, fabH, accB, accC, accD, and accA, in that order. Nucleotide sequence analysis suggested that fabH encoded β-ketoacyl-acyl carrier protein synthase III, that the accB, accC, accD, and accA genes encoded biotin carboxyl carrier protein, biotin carboxylase, and the β and α subunits of carboxyltransferase, respectively, and that these genes were clustered. The organization of acc genes was different from that reported for Escherichia coli, for Bacillus subtilis, and for Pseudomonas aeruginosa. E. coli accB and accD mutations were complemented by the L. plantarum accB and accD genes, respectively. The predicted products of all five genes were confirmed by using the T7 expression system in E. coli. The gene product of accB was biotinylated in E. coli. Northern and primer extension analyses demonstrated that the five genes in L. plantarum were regulated polycistronically in an acc operon. PMID:11133475

  6. Non-chromate Passivation for LHE ZnNi

    DTIC Science & Technology

    2017-03-01

    control of coatings and processes. Development of an alternative methodology that is simple, repeatable, non -destructive, and capable of scanning across...FINAL REPORT Non -chromate Passivation for LHE ZnNi SERDP Project WP-2527 JANUARY 2017 Matt O’Keefe Missouri S&T...valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 2. REPORT TYPE 3. DATES COVERED (From

  7. Integration of polarization and chromatic cues in the insect sky compass.

    PubMed

    el Jundi, Basil; Pfeiffer, Keram; Heinze, Stanley; Homberg, Uwe

    2014-06-01

    Animals relying on a celestial compass for spatial orientation may use the position of the sun, the chromatic or intensity gradient of the sky, the polarization pattern of the sky, or a combination of these cues as compass signals. Behavioral experiments in bees and ants, indeed, showed that direct sunlight and sky polarization play a role in sky compass orientation, but the relative importance of these cues are species-specific. Intracellular recordings from polarization-sensitive interneurons in the desert locust and monarch butterfly suggest that inputs from different eye regions, including polarized-light input through the dorsal rim area of the eye and chromatic/intensity gradient input from the main eye, are combined at the level of the medulla to create a robust compass signal. Conflicting input from the polarization and chromatic/intensity channel, resulting from eccentric receptive fields, is eliminated at the level of the anterior optic tubercle and central complex through internal compensation for changing solar elevations, which requires input from a circadian clock. Across several species, the central complex likely serves as an internal sky compass, combining E-vector information with other celestial cues. Descending neurons, likewise, respond both to zenithal polarization and to unpolarized cues in an azimuth-dependent way.

  8. Estimation of chromatic errors from broadband images for high contrast imaging

    NASA Astrophysics Data System (ADS)

    Sirbu, Dan; Belikov, Ruslan

    2015-09-01

    Usage of an internal coronagraph with an adaptive optical system for wavefront correction for direct imaging of exoplanets is currently being considered for many mission concepts, including as an instrument addition to the WFIRST-AFTA mission to follow the James Web Space Telescope. The main technical challenge associated with direct imaging of exoplanets with an internal coronagraph is to effectively control both the diffraction and scattered light from the star so that the dim planetary companion can be seen. For the deformable mirror (DM) to recover a dark hole region with sufficiently high contrast in the image plane, wavefront errors are usually estimated using probes on the DM. To date, most broadband lab demonstrations use narrowband filters to estimate the chromaticity of the wavefront error, but this reduces the photon flux per filter and requires a filter system. Here, we propose a method to estimate the chromaticity of wavefront errors using only a broadband image. This is achieved by using special DM probes that have sufficient chromatic diversity. As a case example, we simulate the retrieval of the spectrum of the central wavelength from broadband images for a simple shaped- pupil coronagraph with a conjugate DM and compute the resulting estimation error.

  9. The first prototype of chromatic pupillometer for objective perimetry in retinal degeneration patients

    NASA Astrophysics Data System (ADS)

    Rotenstreich, Ygal; Chibel, Ron; Haj Yahia, Soad; Achiron, Asaf; Mahajna, Mohamad; Belkin, Michael; Sher, Ifat

    2015-03-01

    We recently demonstrated the feasibility of quantifying pupil responses (PR) to multifocal chromatic light stimuli for objectively assessing visual field (VF). Here we assessed a second-generation chromatic multifocal pupillometer device with 76 LEDs of 18 degree visual field and a smaller spot size (2mm diameter), aimed of achieving better perimetric resolution. A computerized infrared pupillometer was used to record PR to short- and long-wavelength stimuli (peak 485 nm and 640 nm, respectively) presented by 76 LEDs, 1.8mm spot size, at light intensities of 10-1000 cd/m2 at different points of the 18 degree VF. PR amplitude was measured in 11 retinitis pigmentosa (RP) patients and 20 normal agedmatched controls. RP patients demonstrated statistically significant reduced pupil contraction amplitude in majority of perimetric locations under testing conditions that emphasized rod contribution (short-wavelength stimuli at 200 cd/m2) in peripheral locations (p<0.05). By contrast, the amplitude of pupillary responses under testing conditions that emphasized cone cell contribution (long-wavelength stimuli at 1000 cd/m2) were not significantly different between the groups in majority of perimetric locations, particularly in central locations. Minimal pupil contraction was recorded in areas that were non-detected by chromatic Goldmann. This study demonstrates the feasibility of using pupillometerbased chromatic perimetry for objectively assessing VF defects and retinal function in patients with retinal degeneration. This method may be used to distinguish between the damaged cells underlying the VF defect.

  10. In vivo subjective and objective longitudinal chromatic aberration after bilateral implantation of the same design of hydrophobic and hydrophilic intraocular lenses.

    PubMed

    Vinas, Maria; Dorronsoro, Carlos; Garzón, Nuria; Poyales, Francisco; Marcos, Susana

    2015-10-01

    To measure the longitudinal chromatic aberration in vivo using psychophysical and wavefront-sensing methods in patients with bilateral implantation of monofocal intraocular lenses (IOLs) of similar aspheric design but different materials (hydrophobic Podeye and hydrophilic Poday). Instituto de Optica, Consejo Superior de Investigaciones Cientificas, Madrid, Spain. Prospective observational study. Measurements were performed with the use of psychophysical (480 to 700 nm) and wavefront-sensing (480 to 950 nm) methods using a custom-developed adaptive optics system. Chromatic difference-of-focus curves were obtained from best-focus data at each wavelength, and the longitudinal chromatic aberration was obtained from the slope of linear regressions to those curves. The longitudinal chromatic aberration from psychophysical measurements was 1.37 diopters (D) ± 0.08 (SD) (hydrophobic) and 1.21 ± 0.08 D (hydrophilic). From wavefront-sensing, the longitudinal chromatic aberration was 0.88 ± 0.07 D and 0.73 ± 0.09 D, respectively. At 480 to 950 nm, the longitudinal chromatic aberration was 1.27 ± 0.09 D (hydrophobic) and 1.02 ± 0.13 D (hydrophilic). The longitudinal chromatic aberration was consistently higher in eyes with the hydrophobic IOL than in eyes with the hydrophilic IOL (a difference of 0.16 D and 0.15 D, respectively). Similar to findings in young phakic eyes, the longitudinal chromatic aberration from the psychophysical method was consistently higher than from wavefront-sensing, by 0.48 D (35.41%) for the hydrophobic IOL and 0.48 D (39.43%) for the hydrophilic IOL. Longitudinal chromatic aberrations were smaller with hydrophilic IOLs than with hydrophobic IOLs of the same design. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  11. The influence of L-opsin gene polymorphisms and neural ageing on spatio-chromatic contrast sensitivity in 20-71 year olds.

    PubMed

    Dees, Elise W; Gilson, Stuart J; Neitz, Maureen; Baraas, Rigmor C

    2015-11-01

    Chromatic contrast sensitivity may be a more sensitive measure of an individual's visual function than achromatic contrast sensitivity. Here, the first aim was to quantify individual- and age-related variations in chromatic contrast sensitivity to a range of spatial frequencies for stimuli along two complementary directions in color space. The second aim was to examine whether polymorphisms at specific amino acid residues of the L- and M-opsin genes (OPN1LW and OPN1MW) known to affect spectral tuning of the photoreceptors could influence spatio-chromatic contrast sensitivity. Chromatic contrast sensitivity functions were measured in 50 healthy individuals (20-71 years) employing a novel pseudo-isochromatic grating stimulus. The spatio-chromatic contrast sensitivity functions were found to be low pass for all subjects, independent of age and color vision. The results revealed a senescent decline in spatio-chromatic contrast sensitivity. There were considerable between-individual differences in sensitivity within each age decade for individuals 49 years old or younger, and age did not predict sensitivity for these age decades alone. Forty-six subjects (including a color deficient male and eight female carriers) were genotyped for L- and M-opsin genes. The Ser180Ala polymorphisms on the L-opsin gene were found to influence the subject's color discrimination and their sensitivity to spatio-chromatic patterns. The results expose the significant role of neural and genetic factors in the deterioration of visual function with increasing age. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Ultra-low power high-dynamic range color pixel embedding RGB to r-g chromaticity transformation

    NASA Astrophysics Data System (ADS)

    Lecca, Michela; Gasparini, Leonardo; Gottardi, Massimo

    2014-05-01

    This work describes a novel color pixel topology that converts the three chromatic components from the standard RGB space into the normalized r-g chromaticity space. This conversion is implemented with high-dynamic range and with no dc power consumption, and the auto-exposure capability of the sensor ensures to capture a high quality chromatic signal, even in presence of very bright illuminants or in the darkness. The pixel is intended to become the basic building block of a CMOS color vision sensor, targeted to ultra-low power applications for mobile devices, such as human machine interfaces, gesture recognition, face detection. The experiments show that significant improvements of the proposed pixel with respect to standard cameras in terms of energy saving and accuracy on data acquisition. An application to skin color-based description is presented.

  13. Population impact of the 2017 ACC/AHA guidelines compared with the 2013 ESH/ESC guidelines for hypertension management.

    PubMed

    Vaucher, Julien; Marques-Vidal, Pedro; Waeber, Gérard; Vollenweider, Peter

    2018-01-01

    Background The 2017 ACC/AHA guidelines on hypertension management recommend the introduction of antihypertensive treatment for patients with new stage 1 hypertension thresholds (130-139/80-89 mm Hg) and with a cardiovascular disease or related condition. We compared the Swiss population and economic impact of antihypertensive treatment of the 2017 ACC/AHA guidelines with the 2013 European guidelines. Methods Analyses were based on 4438 participants (aged 45-85 years; 2448 women) of the CoLaus|PsyCoLaus study recruited between 2014-2017. Participants eligible for antihypertensive treatment according to the 2017 ACC/AHA and 2013 European guidelines were sex and age standardised using the Swiss population for 2016. In addition, we estimated the population-wide annual costs of antihypertensive treatment. Results Individuals eligible for antihypertensive treatment were 40.3% (95% confidence interval 38.5-42.1) and 31.3% (29.7-32.9) according to the 2017 ACC/AHA and 2013 European guidelines, respectively. That difference would translate into approximately 250,000 additional individuals eligible for antihypertensive treatment, corresponding to an additional annual cost of 72.5 million CHF (63.0 million EUR). Conclusion The 2017 ACC/AHA guidelines on the management of hypertension substantially increase the number of individuals eligible for antihypertensive treatment compared to the 2013 European guidelines. While implementation of the 2017 ACC/AHA guidelines is expected to lead to cost reduction by preventing cardiovascular diseases, that reduction might be mitigated by the costs incurred by antihypertensive treatments in a larger proportion of the population.

  14. [Chromaticity and optical spectrum colorimetry of the tongue color in different syndromes of primary hepatic carcinoma].

    PubMed

    Xu, Ying; Zeng, Chang-chun; Cai, Xiu-yu; Guo, Rong-ping; Nie, Guang; Jin, Ying

    2012-11-01

    In this study, the optical data of tongue color of different syndromes in primary hepatic carcinoma (PHC) were detected by optical spectrum colorimetry, and the chromaticity of tongue color was compared and analyzed. The tongue color characteristics of different syndromes in PHC and the relationship between different syndromes and tongue color were also investigated. Tongue color data from 133 eligible PHC patients were collected by optical spectrum colorimetry and the patients were divided into 4 syndrome groups according to their clinical features. The syndrome groups were liver depression and spleen deficiency (LDSD), accumulation of damp-heat (ADH), deficiency of liver and kidney yin (DLKY), and qi stagnation and blood stasis (QSBS). The variation characteristics of chromaticity coordinates, dominant wavelength, excitation purity and the distribution in the International Commission on Illumination (CIE) LAB uniform color space were measured. At the same time, the differences of overall chromatism, clarity, chroma, saturation and hue were also calculated and analyzed. PHC patients in different syndrome groups exhibited differences in chromaticity coordinates. The dominant wavelength of QSBS was distinctly different from that of the other 3 syndromes. Excitation purity in the syndromes of LDSD, ADH and DLKY showed gradual increases (P<0.01). Different syndromes in the CIE LAB color three-dimensional space showed differences in tongue color distribution areas. The CIE hue-angle value of QSBS was negative, and different from that of the other 3 syndromes (P<0.01). CIE chroma in the syndromes of LDSD, ADH and DLKY showed gradual increases (P<0.01), the same as excitation purity. In the comparison of chromatism, tongue color variations in different syndromes were quantified by human observation. This study shows that tongue color diagnosis according to the syndrome classifications of traditional Chinese medicine can be quantified with optical spectrum colorimetry

  15. Increased statin eligibility based on ACC/AHA versus NCEP guidelines for high cholesterol management in Chile.

    PubMed

    Echeverría, Guadalupe; Dussaillant, Catalina; Villarroel, Luis; Rigotti, Attilio

    2016-01-01

    In 2013, the American College of Cardiology and the American Heart Association (ACC/AHA) jointly released new guidelines for cardiovascular risk assessment and cholesterol management that substantially modified the previous recommendations proposed by the National Cholesterol Education Program (NCEP) in 2001. The relative impact of these new guidelines on potential statin use has not been estimated in Latin American populations. To estimate and compare eligibility for statin therapy based on ACC/AHA and NCEP guidelines in adult Chilean population. Using data from the last National Health Survey (2009-2010 NHS), we conducted a cross-sectional analysis in a ​representative sample of the Chilean adult population and calculated the proportion of individuals that would receive statins under each set of guidelines. According to ACC/AHA guidelines, the population eligible for statin treatment increased from 21.7% (NCEP guidelines) to 33.2% (overall 53% increase). This effect was more pronounced among women (29.6% under ACC/AHA vs 15.6% under NCEP) and with those of advanced age (75% of the subjects >60 years of age compared with 46% under NCEP). The newly eligible group included more women and older subjects and individuals with lower LDL cholesterol levels. Compared with NCEP recommendations, the new ACC/AHA guidelines significantly increased the number of Chilean adults eligible for statin therapy. Full implementation of the new recommendations may have important public health implications in Chile and other Latin American countries, as more women and older subjects without cardiovascular disease would qualify for statin treatment. Copyright © 2016 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  16. Study of chromatic adaptation using memory color matches, Part I: neutral illuminants.

    PubMed

    Smet, Kevin A G; Zhai, Qiyan; Luo, Ming R; Hanselaer, Peter

    2017-04-03

    Twelve corresponding color data sets have been obtained using the long-term memory colors of familiar objects as target stimuli. Data were collected for familiar objects with neutral, red, yellow, green and blue hues under 4 approximately neutral illumination conditions on or near the blackbody locus. The advantages of the memory color matching method are discussed in light of other more traditional asymmetric matching techniques. Results were compared to eight corresponding color data sets available in literature. The corresponding color data was used to test several linear (von Kries, RLAB, etc.) and nonlinear (Hunt & Nayatani) chromatic adaptation transforms (CAT). It was found that a simple two-step von Kries, whereby the degree of adaptation D is optimized to minimize the DEu'v' prediction errors, outperformed all other tested models for both memory color and literature corresponding color sets, whereby prediction errors were lower for the memory color sets. The predictive errors were substantially smaller than the standard uncertainty on the average observer and were comparable to what are considered just-noticeable-differences in the CIE u'v' chromaticity diagram, supporting the use of memory color based internal references to study chromatic adaptation mechanisms.

  17. Analyzing of chromaticity temperature of novel bulb composed of PDMS and phosphor

    NASA Astrophysics Data System (ADS)

    Novak, M.; Fajkus, M.; Jargus, J.; Bednarek, L.; Cubik, J.; Cvejn, D.; Vasinek, V.

    2017-10-01

    The authors of this article focused on the issue of measurement of the chromaticity temperature of proposed bulbs made from polydimethylsiloxane, depending on the temperature of proposed bulbs. The advantage of this solution is the immunity to electromagnetic interference (EMI) and the ability to use, for example in dangerous environments (such as mines, factories, etc.). For the realization of incandescent bulbs was used transparent two-component elastomer Sylgard 184. A mixture of polydimethylsiloxane (PDMS) and a curing agent in a defined ratio (10:1) and admixture with garnet phosphor YAG: Ce was cured in the temperature box at temperature 90°C +/- 3°C in the shape of the bulbs. All experiments were realized with eight different weight ratios of phosphor and Sylgard 184. Optical power (5 W) from a laser with a wavelength of 455 nm was fed to the proposed bulbs using the cylindrical waveguide of polydimethylsiloxane with a diameter of 5 mm. Chromaticity temperature was measured by two temperature sensors for 12h. The outcome of this study is the evaluation of the chromaticity temperature of output light depending on temperature variations of proposed bulbs due to the conversion of optical power into heat.

  18. Suppression of mutants aberrant in light intensity responses of complementary chromatic adaptation.

    PubMed Central

    Casey, E S; Kehoe, D M; Grossman, A R

    1997-01-01

    Complementary chromatic adaptation is a process in which cyanobacteria alter the pigment protein (phycocyanin and phycoerythrin) composition of their light-harvesting complexes, the phycobilisomes, to help optimize the absorbance of prevalent wavelengths of light in the environment. Several classes of mutants that display aberrant complementary chromatic adaptation have been isolated. One of the mutant classes, designated "blue" or FdB, accumulates high levels of the blue chromoprotein phycocyanin in low-intensity green light, a condition that normally suppresses phycocyanin synthesis. We demonstrate here that the synthesis of the phycocyanin protein and mRNA in the FdB mutants can be suppressed by increasing the intensity of green light. Hence, these mutants have a decreased sensitivity to green light with respect to suppression of phycocyanin synthesis. Although we were unable to complement the blue mutants, we did isolate genes that could suppress the mutant phenotype. These genes, which have been identified previously, encode a histidine kinase sensor and response regulator protein that play key roles in controlling complementary chromatic adaptation. These findings are discussed with respect to the mechanism by which light quality and quantity control the biosynthesis of the phycobilisome. PMID:9226271

  19. [Study on garlic oil combined with 5-FU induced apoptosis of adenoid cystic carcinoma cell line ACC-M].

    PubMed

    Wu, Fayin; Zhou, Hefeng; Fan, Zhiying; Zhu, Yawen; Li, Yongye; Yao, Yukun; Ran, Dan

    2014-02-01

    To observe the effect of garlic oil combined with 5-FU induced apoptosis of adenoid cystic carcinoma cell line ACC-M. Human salivary in adenoid cystic carcinoma cell line AC-M was cultured, divided into the experimental group (5-FU group, garlic oil group, garlic oil + 5-FU group) and the control group, to observe the growth activity of tumor cells by MTT methods; to analyse the changes of cell cycle and apoptosis rate by flow cytometry. MTT experiments showed that 5-FU, garlic oil, garlic oil and 5-FU on ACC-M cells have inhibition in different concentration, with the increase of concentration and action time of the rise; Cell cycle analysis showed significant changes in flow cytometry. With the increase of concentration and the acting time, the G0/G1, phase of the cell ratio increased, S had no significant change, but G2/M phase cells decreased. Apoptosis rate display showed garlic oil combined with 5-FU induced apoptosis of ACC-M cells was significantly stronger than single group. Garlic oil can effectively induce the apoptosis of adenoid cystic carcinoma cell line ACC-M. The effect of garlic oil combined with 5-FU on ACC-M cells was stronger than the garlic oil, 5-FU used alone.

  20. Copper tolerance and copper accumulation of herbaceous plants colonizing inactive California copper mines

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kruckeberg, A.L.; Wu, L.

    1992-06-01

    Herbaceous plant species colonizing four copper mine waste sites in northern California were investigated for copper tolerance and copper accumulation. Copper tolerance was found in plant species colonizing soils with high concentrations of soil copper. Seven of the eight plant species tested were found at more than one copper mine. The mines are geographically isolated, which makes dispersal of seeds from one mine to another unlikely. Tolerance has probably evolved independently at each site. The nontolerant field control population of Vulpia microstachya displays significantly higher tolerance to copper at all copper concentration levels tested than the nontolerant Vulpia myrous population,more » and the degree of copper tolerance attained by V. microstachya at the two copper mines was much greater than that found in V. myrous. It suggests that even in these two closely related species, the innate tolerance in their nontolerant populations may reflect their potential for evolution of copper tolerance and their ability to initially colonize copper mine waste sites. The shoot tissue of the copper mine plants of Arenaria douglasii, Bromous mollis, and V. microstachya accumulated less copper than those plants of the same species from the field control sites when the two were grown in identical conditions in nutrient solution containing copper. The root tissue of these mine plants contain more copper than the roots of the nonmine plants. This result suggests that exclusion of copper from the shoots, in part by immobilization in the roots, may be a feature of copper tolerance. No difference in the tissue copper concentration was detected between tolerant and nontolerant plants of Lotus purshianus, Lupinus bicolor, and Trifolium pratense even though the root tissue had more copper than the leaves.« less

  1. Lead chromate detected as a source of atmospheric Pb and Cr (VI) pollution.

    PubMed

    Lee, Pyeong-Koo; Yu, Soonyoung; Chang, Hye Jung; Cho, Hye Young; Kang, Min-Ju; Chae, Byung-Gon

    2016-10-25

    Spherical black carbon aggregates were frequently observed in dust dry deposition in Daejeon, Korea. They were tens of micrometers in diameter and presented a mixture of black carbon and several mineral phases. Transmission electron microscopy (TEM) observations with energy-dispersive X-ray spectroscopy (EDS) and selected area diffraction pattern (SADP) analyses confirmed that the aggregates were compact and included significant amounts of lead chromate (PbCrO 4 ). The compositions and morphologies of the nanosized lead chromate particles suggest that they probably originated from traffic paint used in roads and were combined as discrete minerals with black carbon. Based on Pb isotope analysis and air-mass backward trajectories, the dust in Daejeon received a considerable input of anthropogenic pollutants from heavily industrialized Chinese cities, which implies that long-range transported aerosols containing PbCrO 4 were a possible source of the lead and hexavalent chromium levels in East Asia. Lead chromate should be considered to be a source of global atmospheric Pb and Cr(VI) pollution, especially given its toxicity.

  2. Lead chromate detected as a source of atmospheric Pb and Cr (VI) pollution

    NASA Astrophysics Data System (ADS)

    Lee, Pyeong-Koo; Yu, Soonyoung; Chang, Hye Jung; Cho, Hye Young; Kang, Min-Ju; Chae, Byung-Gon

    2016-10-01

    Spherical black carbon aggregates were frequently observed in dust dry deposition in Daejeon, Korea. They were tens of micrometers in diameter and presented a mixture of black carbon and several mineral phases. Transmission electron microscopy (TEM) observations with energy-dispersive X-ray spectroscopy (EDS) and selected area diffraction pattern (SADP) analyses confirmed that the aggregates were compact and included significant amounts of lead chromate (PbCrO4). The compositions and morphologies of the nanosized lead chromate particles suggest that they probably originated from traffic paint used in roads and were combined as discrete minerals with black carbon. Based on Pb isotope analysis and air-mass backward trajectories, the dust in Daejeon received a considerable input of anthropogenic pollutants from heavily industrialized Chinese cities, which implies that long-range transported aerosols containing PbCrO4 were a possible source of the lead and hexavalent chromium levels in East Asia. Lead chromate should be considered to be a source of global atmospheric Pb and Cr(VI) pollution, especially given its toxicity.

  3. Lead chromate detected as a source of atmospheric Pb and Cr (VI) pollution

    PubMed Central

    Lee, Pyeong-Koo; Yu, Soonyoung; Chang, Hye Jung; Cho, Hye Young; Kang, Min-Ju; Chae, Byung-Gon

    2016-01-01

    Spherical black carbon aggregates were frequently observed in dust dry deposition in Daejeon, Korea. They were tens of micrometers in diameter and presented a mixture of black carbon and several mineral phases. Transmission electron microscopy (TEM) observations with energy-dispersive X-ray spectroscopy (EDS) and selected area diffraction pattern (SADP) analyses confirmed that the aggregates were compact and included significant amounts of lead chromate (PbCrO4). The compositions and morphologies of the nanosized lead chromate particles suggest that they probably originated from traffic paint used in roads and were combined as discrete minerals with black carbon. Based on Pb isotope analysis and air-mass backward trajectories, the dust in Daejeon received a considerable input of anthropogenic pollutants from heavily industrialized Chinese cities, which implies that long-range transported aerosols containing PbCrO4 were a possible source of the lead and hexavalent chromium levels in East Asia. Lead chromate should be considered to be a source of global atmospheric Pb and Cr(VI) pollution, especially given its toxicity. PMID:27779222

  4. Callitriche cophocarpa (water starwort) proteome under chromate stress: evidence for induction of a quinone reductase.

    PubMed

    Kaszycki, Paweł; Dubicka-Lisowska, Aleksandra; Augustynowicz, Joanna; Piwowarczyk, Barbara; Wesołowski, Wojciech

    2018-03-01

    Chromate-induced physiological stress in a water-submerged macrophyte Callitriche cophocarpa Sendtn. (water starwort) was tested at the proteomic level. The oxidative stress status of the plant treated with 1 mM Cr(VI) for 3 days revealed stimulation of peroxidases whereas catalase and superoxide dismutase activities were similar to the control levels. Employing two-dimensional electrophoresis, comparative proteomics enabled to detect five differentiating proteins subjected to identification with mass spectrometry followed by an NCBI database search. Cr(VI) incubation led to induction of light harvesting chlorophyll a/b binding protein with a concomitant decrease of accumulation of ribulose bisphosphate carboxylase (RuBisCO). The main finding was, however, the identification of an NAD(P)H-dependent dehydrogenase FQR1, detectable only in Cr(VI)-treated plants. The FQR1 flavoenzyme is known to be responsive to oxidative stress and to act as a detoxification protein by protecting the cells against oxidative damage. It exhibits the in vitro quinone reductase activity and is capable of catalyzing two-electron transfer from NAD(P)H to several substrates, presumably including Cr(VI). The enhanced accumulation of FQR1 was chromate-specific since other stressful conditions, such as salt, temperature, and oxidative stresses, all failed to induce the protein. Zymographic analysis of chromate-treated Callitriche shoots showed a novel enzymatic protein band whose activity was attributed to the newly identified enzyme. We suggest that Cr(VI) phytoremediation with C. cophocarpa can be promoted by chromate reductase activity produced by the induced quinone oxidoreductase which might take part in Cr(VI) → Cr(III) bioreduction process and thus enable the plant to cope with the chromate-generated oxidative stress.

  5. Amino-functionalized MCM-41 and MCM-48 for the removal of chromate and arsenate.

    PubMed

    Benhamou, A; Basly, J P; Baudu, M; Derriche, Z; Hamacha, R

    2013-08-15

    The aim of the present work was to investigate the efficiency of three amino-functionalized (hexadecylamine, dodecylamine, and dimethyldodecylamine) mesoporous silicas (MCM-41 and MCM-48) toward the adsorption of arsenate and chromate. Hexadecylamine-functionalized materials were characterized; BET surface areas, pore volumes, and sizes decreased with the functionalization, whereas XRD patterns show that the hexagonal structure of MCM-41 and the cubic structure of MCM-48 were not modified. The zeta potential decreases with pH and the highest arsenate and chromate removal was observed at the lowest pHs. Adsorption of chromium and arsenate was significantly enhanced after functionalization and amino-functionalized MCM-41 adsorb larger amounts of arsenate when compared to expanded MCM-48 materials. Chromate sorption capacities increased with the chain length and the larger capacities were obtained with hexadecylamine-functionalized mesoporous silicas. Mesoporous silicas modified by dimethyldodecylamine exhibited the higher arsenate sorption capacities. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Reduced Chromatic Discrimination in Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Franklin, Anna; Sowden, Paul; Notman, Leslie; Gonzalez-Dixon, Melissa; West, Dorotea; Alexander, Iona; Loveday, Stephen; White, Alex

    2010-01-01

    Atypical perception in Autism Spectrum Disorders (ASD) is well documented (Dakin & Frith, 2005). However, relatively little is known about colour perception in ASD. Less accurate performance on certain colour tasks has led some to argue that chromatic discrimination is reduced in ASD relative to typical development (Franklin, Sowden, Burley,…

  7. Obesity Drives Th17 Cell Differentiation by Inducing the Lipid Metabolic Kinase, ACC1.

    PubMed

    Endo, Yusuke; Asou, Hikari K; Matsugae, Nao; Hirahara, Kiyoshi; Shinoda, Kenta; Tumes, Damon J; Tokuyama, Hirotake; Yokote, Koutaro; Nakayama, Toshinori

    2015-08-11

    Chronic inflammation due to obesity contributes to the development of metabolic diseases, autoimmune diseases, and cancer. Reciprocal interactions between metabolic systems and immune cells have pivotal roles in the pathogenesis of obesity-associated diseases, although the mechanisms regulating obesity-associated inflammatory diseases are still unclear. In the present study, we performed transcriptional profiling of memory phenotype CD4 T cells in high-fat-fed mice and identified acetyl-CoA carboxylase 1 (ACC1, the gene product of Acaca) as an essential regulator of Th17 cell differentiation in vitro and of the pathogenicity of Th17 cells in vivo. ACC1 modulates the DNA binding of RORγt to target genes in differentiating Th17 cells. In addition, we found a strong correlation between IL-17A-producing CD45RO(+)CD4 T cells and the expression of ACACA in obese subjects. Thus, ACC1 confers the appropriate function of RORγt through fatty acid synthesis and regulates the obesity-related pathology of Th17 cells. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Effects of the inoculations using bacteria producing ACC deaminase on ethylene metabolism and growth of wheat grown under different soil water contents.

    PubMed

    Zhang, Guozhuang; Sun, Yonglin; Sheng, Hao; Li, Haichao; Liu, Xiping

    2018-04-01

    Crop growth and productivity are often impacted by the increased ethylene content induced by adverse environmental conditions such drought. Inoculations with bacteria producing ACC deaminase is considered as a potential biological approach to improve the growth and tolerance of stressed plants by lowering endogenous ethylene level. In this study, germinated wheat seeds were inoculated using three species of the rhizobacteria, which were isolated from the rhizosphere of wheat growing in dryland, and sown in pots. After three weeks, wheat seedlings were exposed to non-limiting water condition, medium drought and severe drought, respectively, for six weeks. The results showed that, irrespective of rhizobacterial inoculations, decreased soil water contents stimulated wheat ethylene metabolism, which was reflected by the significantly increased activity of ACC synthetase and ACC oxidase, besides an increased content of ACC both in the roots and leaves, and an enhanced capacity of leaves to release ethylene, concomitant with a significant decline in shoot and roots biomass. The inoculations of all three rhizobacterial species under each water condition reduced ACC content in wheat leaves, but effects of the inoculations on ACC synthase and ACC oxidase activity in the leaves and roots, ACC content in the roots, the capacity of leaves to release ethylene, and wheat growth varied with water conditions and bacterial species. Hence, both soil water conditions and rhizobacterial inoculations acted on all the processes of ethylene metabolism, with the former being dominant. The inoculations under non-limiting water condition and medium drought promoted shoot and root growth of wheat plants. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  9. Overexpression of ACC gene from oleaginous yeast Lipomyces starkeyi enhanced the lipid accumulation in Saccharomyces cerevisiae with increased levels of glycerol 3-phosphate substrates.

    PubMed

    Wang, Jiancai; Xu, Ronghua; Wang, Ruling; Haque, Mohammad Enamul; Liu, Aizhong

    2016-06-01

    The conversion of acetyl-CoA to malonyl-CoA by acetyl-CoA carboxylase (ACC) is the rate-limiting step in fatty acid biosynthesis. In this study, a gene coding for ACC was isolated and characterized from an oleaginous yeast, Lipomyces starkeyi. Real-time quantitative PCR (qPCR) analysis of L. starkeyi acetyl-CoA carboxylase gene (LsACC1) showed that the expression levels were upregulated with the fast accumulation of lipids. The LsACC1 was co-overexpressed with the glycerol 3-phosphate dehydrogenase gene (GPD1), which regulates lipids biosynthesis by supplying another substrates glycerol 3-phosphate for storage lipid assembly, in the non-oleaginous yeast Saccharomyces cerevisiae. Further, the S. cerevisiae acetyl-CoA carboxylase (ScACC1) was transferred with GPD1 and its function was analyzed in comparison with LsACC1. The results showed that overexpressed LsACC1 and GPD1 resulted in a 63% increase in S. cerevisiae. This study gives new data in understanding of the molecular mechanisms underlying the regulation of fatty acids and lipid biosynthesis in yeasts.

  10. Mechanisms and fitness implications of photomorphogenesis during chromatic acclimation in cyanobacteria.

    PubMed

    Montgomery, Beronda L

    2016-07-01

    Photosynthetic organisms absorb photons and convert light energy to chemical energy through the process of photosynthesis. Photosynthetic efficiency is tuned in response to the availability of light, carbon dioxide and nutrients to promote maximal levels of carbon fixation, while simultaneously limiting the potential for light-associated damage or phototoxicity. Given the central dependence on light for energy production, photosynthetic organisms possess abilities to tune their growth, development and metabolism to external light cues in the process of photomorphogenesis. Photosynthetic organisms perceive light intensity and distinct wavelengths or colors of light to promote organismal acclimation. Cyanobacteria are oxygenic photosynthetic prokaryotes that exhibit abilities to alter specific aspects of growth, including photosynthetic pigment composition and morphology, in responses to changes in available wavelengths and intensity of light. This form of photomorphogenesis is known as chromatic acclimation and has been widely studied. Recent insights into the photosensory photoreceptors found in cyanobacteria and developments in our understanding of the molecular mechanisms initiated by light sensing to affect the changes characteristic of chromatic acclimation are discussed. I consider cyanobacterial responses to light, the broad diversity of photoreceptors encoded by these organisms, specific mechanisms of photomorphogenesis, and associated fitness implications in chromatically acclimating cyanobacteria. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. Transient VEP and psychophysical chromatic contrast thresholds in children and adults.

    PubMed

    Boon, Mei Ying; Suttle, Catherine M; Dain, Stephen J

    2007-07-01

    It has been found that humans are able to distinguish colours without luminance cues by about 2-4 months of age and that sensitivity to colour difference develops during childhood, reaching a peak around adolescence. This prolonged period of maturation is reflected by improvements in psychophysical threshold measures and by the VEP characteristics of morphology, latency and amplitude. An intra-individual comparison of VEP and psychophysical responses to isoluminant colour stimuli has not been made in children, however, and this was the aim of the present study. VEPs were recorded from 49 subjects, children (age range: 4.8-12.6 years) and adults (age range: 25.7-33.2 years). Psychophysical and VEP thresholds were both measured in 40 of those subjects. Nominally isoluminant chromatic (L-M) sinewave gratings were presented in onset-offset mode and identical stimuli were used for psychophysical and VEP recordings to allow comparison. In agreement with previous reports, morphology of the transient VEP in response to this stimulus differed considerably between children and adults. There was a significant difference between psychophysical and VEP thresholds in children, but not in adults. Our findings support and expand on previous work on maturation of the L-M chromatic pathway and indicate a larger discrepancy between VEP and psychophysical chromatic thresholds in children than in adults.

  12. Chelation in metal intoxication. VIII. Removal of chromium from organs of potassium chromate administered rats.

    PubMed

    Behari, J R; Tandon, S K

    1980-03-01

    Some polyaminocarboxylic acids were examined for their ability to mobilize chromium from certain vital organs, their subcellular fractions, and blood cells of potassium chromate administered rats. Hexamethylene 1,6-diamino tetraacetic acid (TDTA), triethylene tetramine hexaacetic acid (TTHA), and ethylene diamine di (O-hydroxylphenyl acetic acid) (EDDHA) may be useful in preventing or reducing chromate toxicity. No definite relationship could be observed between the structure of the chelating agents and their chromium-removing capacity.

  13. Methods and optical fibers that decrease pulse degradation resulting from random chromatic dispersion

    DOEpatents

    Chertkov, Michael; Gabitov, Ildar

    2004-03-02

    The present invention provides methods and optical fibers for periodically pinning an actual (random) accumulated chromatic dispersion of an optical fiber to a predicted accumulated dispersion of the fiber through relatively simple modifications of fiber-optic manufacturing methods or retrofitting of existing fibers. If the pinning occurs with sufficient frequency (at a distance less than or are equal to a correlation scale), pulse degradation resulting from random chromatic dispersion is minimized. Alternatively, pinning may occur quasi-periodically, i.e., the pinning distance is distributed between approximately zero and approximately two to three times the correlation scale.

  14. The Test and Evaluation of a Non-Chromate Finishing Agent

    NASA Technical Reports Server (NTRS)

    Gulley, H.; Okhio, C. B.; Tacina, Robert (Technical Monitor)

    2000-01-01

    This research is focused on the design, development and implementation of an industry, military and commercial standard testing cell for surface coatings, which focuses on advanced non-chromate materials technology and their commercialization. Currently, within both private and commercial sectors, chromates are used in the corrosion prevention. processes. However, there is a great demand for chromate-free systems that are able to provide equal protection. At the end of this effort, it is intended that a patented alternative to chromate conversion coatings would be tested and processed for commercialization. Thus far, research studies have been concerned primarily with current corrosion knowledge and testing methods. Corrosion can be classified into five categories: The first type is uniform corrosion which is dominated by a uniform thinning due to an even and regular loss of metal. The second type is called localized corrosion in which most of the loss occurs in discrete areas. The third type, metallurgically influenced corrosion is a form of attack where metallurgy plays a significant role. The fourth type, titled mechanically assisted degradation is a form of attack where velocity, abrasion, and hydrodynamics control the corrosion process. The last type of corrosion is defined as environmentally induced cracking which occurs when cracks are produced under specific, premeditated stress. Oddly enough, with these varying classifications, there are not as many standardized corrosion testing sites. Two of the most common testing methods for corrosion are salt spray testing and filiform. Although neither has proven to be absolute, in terms of the resulting observations, our research aims to help provide data that may be used to support the standardization for corrosion testing. We would acquire and use a Singleton Cyclic Corrosion Testing Chamber. Singleton test chambers perform a wide range of commonly used catalytic corrosion tests. They are used throughout the

  15. Variable responses of two VlMYBA gene promoters to ABA and ACC in Kyoho grape berries.

    PubMed

    Zhai, Xiawan; Zhang, Yushu; Kai, Wenbin; Liang, Bin; Jiang, Li; Du, Yangwei; Wang, Juan; Sun, Yufei; Leng, Ping

    2017-04-01

    The VlMYBA subfamily of transcription factors has been known to be the functional regulators in anthocyanin biosynthesis in red grapes. In this study, the expressions of the VlMYBA1-2 and VlMYBA 2 genes, and the responses of the VlMYBA1-2/2 promoters to ABA and ACC treatments in Kyoho grape berries are examined through quantitative real-time PCR analysis and the transient expression assay. The results show that the expressions of VlMYBA1-2/2 increase dramatically after véraison and reach their highest levels when the berries are nearly fully ripe. Exogenous ABA promotes the expressions of VlMYBA1-2/2, whereas the ACC treatment increases the expression of VlMYBA2, however, it has no effect on VlMYBA1-2. The ABA treatment has a faster and stronger effect on berry pigmentation than ACC does. The VlMYBA1-2 promoter sequence contains two ABA response elements (ABRE) but no ethylene response element (ERE), whereas the VlMYBA2 promoter sequence contains two ABRE and one ERE in the upstream region of the start codon. The VlMYBA2 promoter can be activated by both ABA (more effective) and ACC, whereas the VlMYBA1-2 promoter can be activated by ABA only. In sum, ABA can promote the coloring of Kyoho grape by the promotion of VlMYBA1-2/2 transcriptions via activating the response of their promoters to ABA, whereas ethylene only regulates VlMYBA2 through the response activation of its promoter to ACC which partially enhances the coloring. Copyright © 2017 Elsevier GmbH. All rights reserved.

  16. Transport of sup 14 C-IAA and sup 14 C-ACC within floral organs of Ipomoea nil

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kiss, H.G.; Maurice, H.R.; Koning, R.E.

    1989-04-01

    The transport of {sup 14}C-IAA {sup 14}C-ACC from agarose donor blocks applied to I. nil filaments their recovery as {sup 14}C-accumulation into floral organs was examined. The accumulation of the isotopes in the corolla tissue was greater when {sup 14}C-ACC was applied than {sup 14}C-IAA in intact isolated flower buds. Greater levels of the isotopes accumulated in the pistil, with minimal levels in receptacle and calyx tissues from isolated buds. With intact buds, greater levels of the isotopes were recovered in pistil, calyx receptacle tissues. This study provides further evidence for the role of the filaments as transport vectors formore » IAA ACC for the production of ethylene.« less

  17. Determination of the chromatic dispersion of liquids based on the liquid-prism SPR configuration in angular and spectral interrogations

    NASA Astrophysics Data System (ADS)

    Lan, Guoqiang; Liu, Shugang; Wang, Yuxiao; Zhang, Xueru; Song, Yinglin

    2015-10-01

    In this work, we use the liquid-prism SPR sensing configuration to determine the chromatic dispersion of different liquids, since the condition of SPR is sensitive to the refractive index of the liquid prism. We use the glass slide coated with 50 nm Au film as the sensing chip, and use AvaLight - HAL (360 nm - 2500 nm) light source as the broaden band light source in our experiments. We adopt the deionized water as the standard sample to determine the chromatic dispersion of different liquid samples (ethanol and n-hexane), and we implement the experiment through the SPR sensing configuration in angular and spectral interrogations. According to the experimental data, the chromatic dispersions of ethanol and n-hexane are obtained. The proposed technique provides a new high sensitive method for the determination of chromatic dispersion of liquids.

  18. Pursuit Latency for Chromatic Targets

    NASA Technical Reports Server (NTRS)

    Mulligan, Jeffrey B.; Ellis, Stephen R. (Technical Monitor)

    1998-01-01

    The temporal dynamics of eye movement response to a change in direction of stimulus motion has been used to compare the processing speeds of different types of stimuli (Mulligan, ARVO '97). In this study, the pursuit response to colored targets was measured to test the hypothesis that the slow response of the chromatic system (as measured using traditional temporal sensitivity measures such as contrast sensitivity) results in increased eye movement latencies. Subjects viewed a small (0.4 deg) Gaussian spot which moved downward at a speed of 6.6 deg/sec. At a variable time during the trajectory, the dot's direction of motion changed by 30 degrees, either to the right or left. Subjects were instructed to pursue the spot. Eye movements were measured using a video ophthalmoscope with an angular resolution of approximately 1 arc min and a temporal sampling rate of 60 Hz. Stimuli were modulated in chrominance for a variety of hue directions, combined with a range of small luminance increments and decrements, to insure that some of the stimuli fell in the subjects' equiluminance planes. The smooth portions of the resulting eye movement traces were fit by convolving the stimulus velocity with an exponential having variable onset latency, time constant and amplitude. Smooth eye movements with few saccades were observed for all stimuli. Pursuit responses to stimuli having a significant luminance component are well-fit by exponentials having latencies and time constants on the order of 100 msec. Increases in pursuit response latency on the order of 100-200 msec are observed in response to certain stimuli, which occur in pairs of complementary hues, corresponding to the intersection of the stimulus section with the subjects' equiluminant plane. Smooth eye movements can be made in response to purely chromatic stimuli, but are slower than responses to stimuli with a luminance component.

  19. Joint denoising, demosaicing, and chromatic aberration correction for UHD video

    NASA Astrophysics Data System (ADS)

    Jovanov, Ljubomir; Philips, Wilfried; Damstra, Klaas Jan; Ellenbroek, Frank

    2017-09-01

    High-resolution video capture is crucial for numerous applications such as surveillance, security, industrial inspection, medical imaging and digital entertainment. In the last two decades, we are witnessing a dramatic increase of the spatial resolution and the maximal frame rate of video capturing devices. In order to achieve further resolution increase, numerous challenges will be facing us. Due to the reduced size of the pixel, the amount of light also reduces, leading to the increased noise level. Moreover, the reduced pixel size makes the lens imprecisions more pronounced, which especially applies to chromatic aberrations. Even in the case when high quality lenses are used some chromatic aberration artefacts will remain. Next, noise level additionally increases due to the higher frame rates. To reduce the complexity and the price of the camera, one sensor captures all three colors, by relying on Color Filter Arrays. In order to obtain full resolution color image, missing color components have to be interpolated, i.e. demosaicked, which is more challenging than in the case of lower resolution, due to the increased noise and aberrations. In this paper, we propose a new method, which jointly performs chromatic aberration correction, denoising and demosaicking. By jointly performing the reduction of all artefacts, we are reducing the overall complexity of the system and the introduction of new artefacts. In order to reduce possible flicker we also perform temporal video enhancement. We evaluate the proposed method on a number of publicly available UHD sequences and on sequences recorded in our studio.

  20. Health Literacy: Readability of ACC/AHA Online Patient Education Material.

    PubMed

    Kapoor, Karan; George, Praveen; Evans, Matthew C; Miller, Weldon J; Liu, Stanley S

    To determine whether the online patient education material offered by the American College of Cardiology (ACC) and the American Heart Association (AHA) is written at a higher level than the 6th-7th grade level recommended by the National Institute of Health (NIH). Online patient education material from each website was subjected to reading grade level (RGL) analysis using the Readability Studio Professional Edition. One-sample t testing was used to compare the mean RGLs obtained from 8 formulas to the NIH-recommended 6.5 grade level and 8th grade national mean. In total, 372 articles from the ACC website and 82 from the AHA were studied. Mean (±SD) RGLs for the 454 articles were 9.6 ± 2.1, 11.2 ± 2.1, 11.9 ± 1.6, 10.8 ± 1.6, 9.7 ± 2.1, 10.8 ± 0.8, 10.5 ± 2.6, and 11.7 ± 3.5 according to the Flesch-Kincaid grade level (FKGL), Simple Measure of Gobbledygook (SMOG Index), Coleman-Liau Index (CLI), Gunning-Fog Index (GFI), New Dale-Chall reading level formula (NDC), FORCAST, Raygor Readability Estimate (RRE), and Fry Graph (Fry), respectively. All analyzed articles had significantly higher RGLs than both the NIH-recommended grade level of 6.5 and the national mean grade level of 8 (p < 0.00625). Patient education material provided on the ACC and AHA websites is written above the NIH-recommended 6.5 grade level and 8th grade national mean reading level. Additional studies are required to demonstrate whether lowering the RGL of this material improves outcomes among patients with cardiovascular disease. © 2017 S. Karger AG, Basel.

  1. Development and psychometric evaluation of the Assessment of Core CBT Skills (ACCS): An observation-based tool for assessing cognitive behavioral therapy competence.

    PubMed

    Muse, Kate; McManus, Freda; Rakovshik, Sarah; Thwaites, Richard

    2017-05-01

    This article outlines the development and psychometric evaluation of the Assessment of Core CBT Skills (ACCS) rating scale. The ACCS aims to provide a novel assessment framework to deliver formative and summative feedback regarding therapists' performance within observed cognitive-behavioral treatment sessions, and for therapists to rate and reflect on their own performance. Findings from 3 studies are outlined: (a) a feedback study (n = 66) examining content validity, face validity and usability; (b) a focus group (n = 9) evaluating usability and utility; and (c) an evaluation of the psychometric properties of the ACCS in real world cognitive behavioral therapy (CBT) training and routine clinical practice contexts. Results suggest that the ACCS has good face validity, content validity, and usability and provides a user-friendly tool that is useful for promoting self-reflection and providing formative feedback. Scores on both the self and assessor-rated versions of the ACCS demonstrate good internal consistency, interrater reliability, and discriminant validity. In addition, ACCS scores were found to be correlated with, but distinct from, the Revised Cognitive Therapy Scale (CTS-R) and were comparable to CTS-R scores in terms of internal consistency and discriminant validity. In addition, the ACCS may have advantages over the CTS-R in terms of interrater reliability of scores. The studies also provided insight into areas for refinement and a number of modifications were undertaken to improve the scale. In summary, the ACCS is an appropriate and useful measure of CBT competence that can be used to promote self-reflection and provide therapists with formative and summative feedback. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  2. Chromatic Properties of Index of Refraction Gradients in Glass.

    NASA Astrophysics Data System (ADS)

    Ryan-Howard, Danette Patrice

    The chromatic properties of index of refraction gradients have been predicted theoretically and verified experimentally. The use of these materials in the design of color corrected optical systems has been investigated and confirmed by the evaluation of two fabricated lenses. A model for the chromatic properties of gradient index materials has been developed. The index of refraction is calculated based on the composition of the material. Since the index of refraction and the conventional Abbe number change as a function of the composition of the glass, a gradient Abbe number and a partial dispersion are defined. Analysis of combinations of ion exchange pairs and glasses result in a wide range of gradient Abbe numbers and partial dispersions. These ranges can be further extended by using glasses which contain more than one exchange ion or by using mixed salt baths. The chromatic properties were measured with a multiple wavelength A.C. interferometer. The gradient Abbe numbers and partial dispersions for a number of samples were calculated. Evaluation of the samples showed that the index and dispersion data correlated well with that predicted by the model. Thin lens formulae for the paraxial axial color and secondary spectrum of a radial gradient singlet with curves were examined. The design of a single element 10x microscope objective verified the applicability of these formulae. The design of a two element 40x microscope objective showed that a six element diffraction limited 40x objective can be replaced with a two element system composed of one homogeneous lens and one gradient lens without sacrificing either monochromatic performance or color correction. A previously fabricated axial gradient collimator and a fabricated Wood element were evaluated. Correlation of the directly measured quantities, paraxial axial color, secondary spectrum and spherochromatism with the values predicted by the model verified that the predicted superior performance of gradient

  3. Evaluating the corrosiveness of southern pine treated with several wood preservatives using electrochemical techniques

    Treesearch

    Samuel L. Zelinka; Douglas R. Rammer; Donald S. Stone

    2009-01-01

    Chromated copper arsenate (CCA), the most widely used wood preservative of the past 50 years, has been replaced for most uses with alkaline-copper systems such as alkaline copper quaternary (ACQ), copper azole (CuAz) and micronized copper quaternary (MCQ). Preliminary research using high-temperature, high-humidity environments have shown that some of these wood...

  4. Waste management facility accident analysis (WASTE ACC) system: software for analysis of waste management alternatives

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kohout, E.F.; Folga, S.; Mueller, C.

    1996-03-01

    This paper describes the Waste Management Facility Accident Analysis (WASTE{underscore}ACC) software, which was developed at Argonne National Laboratory (ANL) to support the US Department of Energy`s (DOE`s) Waste Management (WM) Programmatic Environmental Impact Statement (PEIS). WASTE{underscore}ACC is a decision support and database system that is compatible with Microsoft{reg_sign} Windows{trademark}. It assesses potential atmospheric releases from accidents at waste management facilities. The software provides the user with an easy-to-use tool to determine the risk-dominant accident sequences for the many possible combinations of process technologies, waste and facility types, and alternative cases described in the WM PEIS. In addition, its structure willmore » allow additional alternative cases and assumptions to be tested as part of the future DOE programmatic decision-making process. The WASTE{underscore}ACC system demonstrates one approach to performing a generic, systemwide evaluation of accident risks at waste management facilities. The advantages of WASTE{underscore}ACC are threefold. First, the software gets waste volume and radiological profile data that were used to perform other WM PEIS-related analyses directly from the WASTE{underscore}MGMT system. Second, the system allows for a consistent analysis across all sites and waste streams, which enables decision makers to understand more fully the trade-offs among various policy options and scenarios. Third, the system is easy to operate; even complex scenario runs are completed within minutes.« less

  5. Presidential Green Chemistry Challenge: 2002 Designing Greener Chemicals Award

    EPA Pesticide Factsheets

    Presidential Green Chemistry Challenge 2002 award winner, Chemical Specialties, developed an alkaline copper quaternary wood preservative to replace chromated copper arsenate preservative phased out due to risk to children.

  6. COUPLED IRON CORROSION AND CHROMATE REDUCTION: MECHANISMS FOR SUBSURFACE REMEDIATION

    EPA Science Inventory

    The reduction of chromium from the Cr(VI) to the Cr- (Ill) state by the presence of elemental, or zero-oxidation-state, iron metal was studied to evaluate the feasibility of such a process for subsurface chromate remediation. Reactions were studied in systems of natural aquifer m...

  7. A Normative Data Set for the Clinical Assessment of Achromatic and Chromatic Contrast Sensitivity Using a qCSF Approach.

    PubMed

    Kim, Yeon Jin; Reynaud, Alexandre; Hess, Robert F; Mullen, Kathy T

    2017-07-01

    The measurement of achromatic sensitivity has been an important tool for monitoring subtle changes in vision as the result of disease or response to therapy. In this study, we aimed to provide a normative data set for achromatic and chromatic contrast sensitivity functions within a common cone contrast space using an abbreviated measurement approach suitable for clinical practice. In addition, we aimed to provide comparisons of achromatic and chromatic binocular summation across spatial frequency. We estimated monocular cone contrast sensitivity functions (CCSFs) using a quick Contrast Sensitivity Function (qCSF) approach for achromatic as well as isoluminant, L/M cone opponent, and S cone opponent stimuli in a healthy population of 51 subjects. We determined the binocular CCSFs for achromatic and chromatic vision to evaluate the degree of binocular summation across spatial frequency for these three different mechanisms in a subset of 20 subjects. Each data set shows consistent contrast sensitivity across the population. They highlight the extremely high cone contrast sensitivity of L/M cone opponency compared with the S-cone and achromatic responses. We also find that the two chromatic sensitivities are correlated across the healthy population. In addition, binocular summation for all mechanisms depends strongly on stimulus spatial frequency. This study, using an approach well suited to the clinic, is the first to provide a comparative normative data set for the chromatic and achromatic contrast sensitivity functions, yielding quantitative comparisons of achromatic, L/M cone opponent, and S cone opponent chromatic sensitivities as a function of spatial frequency.

  8. Immobilization of chromate in hyperalkaline waste streams by green rusts and zero-valent iron.

    PubMed

    Rogers, Christine M; Burke, Ian T; Ahmed, Imad A M; Shaw, Samuel

    2014-01-01

    Zero-valent iron (ZVI) and green rusts can be used as reductants to convert chromium from soluble, highly toxic Cr(VI) to insoluble Cr(III). This study compared the reduction rates of Cr(VI) by ZVI and two carbonate green rust phases in alkaline/hyperalkaline solutions. Batch experiments were carried out with synthetic chromate solutions at pH 7.7-12.3 and a chromite ore processing residue (COPR) leachate (pH approximately 12.2). Green rust removes chromate from high pH solutions (pH 10-12.5) very rapidly (<400 s). Chromate reduction rates for both green rust phases were consistently higher than for ZVI throughout the pH range studied; the surface area normalized rate constants were two orders of magnitude higher in the COPR leachate solution at pH 12.2. The performances of both green rusts were unaffected by changes in pH. In contrast, ZVI exhibited a marked decline in reduction rate with increasing pH to become almost ineffective above pH12.

  9. Experimental verification of the minimum number of diffractive zones for effective chromatic correction in the LWIR

    NASA Astrophysics Data System (ADS)

    Ramsey, J. L.; Walsh, K. F.; Smith, M.; Deegan, J.

    2016-05-01

    With the move to smaller pixel sizes in the longwave IR region there has been a push for shorter focal length lenses that are smaller, cheaper and lighter and that resolve lower spatial frequencies. As a result lenses must have better correction for both chromatic and monochromatic aberrations. This leads to the increased use of aspheres and diffractive optical elements (kinoforms). With recent developments in the molding of chalcogenide materials these aspheres and kinoforms are more cost effective to manufacture. Without kinoforms the axial color can be on the order of 15 μm which degrades the performance of the lens at the Nyquist frequency. The kinoforms are now on smaller elements and are correcting chromatic aberration which is on the order of the design wavelength. This leads to kinoform structures that do not require large phase changes and therefore have 1.5 to just over 2 zones. The question becomes how many zones are required to correct small amounts of chromatic aberration in the system and are they functioning as predicted by the lens design software? We investigate both the design performance and the as-built performance of two designs that incorporate kinoforms for the correction of axial chromatic aberration.

  10. Effects of plant growth-promoting bacteria isolated from copper tailings on plants in sterilized and non-sterilized tailings.

    PubMed

    Liu, Weiqiu; Yang, Chao; Shi, Si; Shu, Wensheng

    2014-02-01

    Ten strains of Cu-tolerant bacteria with potential plant growth-promoting ability were isolated by selecting strains with the ability to use 1-aminocyclopropane-1-carboxylate as a sole nitrogen source (designated ACC-B) or fix nitrogen (designated FLN-B) originating from the rhizosphere of plants growing on copper tailings. All 10 strains proved to have intrinsic ability to produce indole acetic acid and siderophores, and most of them could mobilize insoluble phosphate. In addition, a greenhouse study showed that ACC-B, FLN-B and a mixture of both had similar, potent ability to stimulate growth of Pennisetum purpureum, Medicago sativa and Oenothera erythrosepala plants grown on sterilized tailings. For instance, above-ground biomass of P. purpureum was 278-357% greater after 60d growth on sterilized tailings in their presence. They could also significantly promote the growth of the plants grown on non-sterilized tailings, though the growth-promoting effects were much weaker. So, strategies for using of the plant growth-promoting bacteria in the practice of phytoremediation deserve further studies to get higher growth-promoting efficiency. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. The ability of the 2013 ACC/AHA cardiovascular risk score to identify rheumatoid arthritis patients with high coronary artery calcification scores

    PubMed Central

    Kawai, Vivian K.; Chung, Cecilia P.; Solus, Joseph F.; Oeser, Annette; Raggi, Paolo; Stein, C. Michael

    2014-01-01

    Objective Patients with rheumatoid arthritis (RA) have increased risk of atherosclerotic cardiovascular disease (ASCVD) that is underestimated by the Framingham risk score (FRS). We hypothesized that the 2013 ACC/AHA 10-year risk score would perform better than the FRS and the Reynolds risk score (RRS) in identifying RA patients known to have elevated cardiovascular risk based on high coronary artery calcification (CAC) scores. Methods Among 98 RA patients eligible for risk stratification using the ACC/AHA score we identified 34 patients with high CAC (≥ 300 Agatston units or ≥75th percentile) and compared the ability of the 10-year FRS, RRS and the ACC/AHA risk scores to correctly assign these patients to an elevated risk category. Results All three risk scores were higher in patients with high CAC (P values <0.05). The percentage of patients with high CAC correctly assigned to the elevated risk category was similar among the three scores (FRS 32%, RRS 32%, ACC/AHA 41%) (P=0.233). The c-statistics for the FRS, RRS and ACC/AHA risk scores predicting the presence of high CAC were 0.65, 0.66, and 0.65, respectively. Conclusions The ACC/AHA 10-year risk score does not offer any advantage compared to the traditional FRS and RRS in the identification of RA patients with elevated risk as determined by high CAC. The ACC/AHA risk score assigned almost 60% of patients with high CAC into a low risk category. Risk scores and standard risk prediction models used in the general population do not adequately identify many RA patients with elevated cardiovascular risk. PMID:25371313

  12. Competitive adsorption of boric acid and chromate onto alumina in aqueous solutions.

    PubMed

    Demetriou, A; Pashalidis, I

    2014-01-01

    The competitive adsorption of boric acid and chromate from aqueous solutions by alumina has been investigated by spectrophotometry at pH 8, ionic strength = 0.0, 0.1 and 1.0 M NaClO4, T = 22 ± 3 °C and under normal atmospheric conditions. The experimental data show that addition of excess boric acid in the system leads to the increase of Cr(VI) concentration in solution, indicating the replacement of adsorbed chromate by boron on the alumina surface. Data evaluation results in the determination of the competition reaction constant and the formation constant of the Cr(VI) surface complexes, which are logKCr(VI)-B(III) = -3.5 ± 0.2 and logβ*Cr = 7.6 ± 0.3, respectively.

  13. Functionalized granular activated carbon and surface complexation with chromates and bi-chromates in wastewater.

    PubMed

    Singha, Somdutta; Sarkar, Ujjaini; Luharuka, Pallavi

    2013-03-01

    Cr(VI) is present in the aqueous medium as chromate (CrO4(2-)) and bi-chromate (HCrO4(-)). Functionalized granular activated carbons (FACs) are used as adsorbents in the treatment of wastewaters containing hexavalent chromium. The FACs are prepared by chemical modifications of granular activated carbons (GACs) using functionalizing agents like HNO3, HCl and HF. The Brunauer, Emmett and Teller surface areas of FAC-HCl (693.5m(2)/g), FAC-HNO3 (648.8m(2)/g) and FAC-HF (726.2m(2)/g) are comparable to the GAC (777.7m(2)/g). But, the adsorption capacity of each of the FAC-HNO3, FAC-HCl and FAC-HF is found to be higher than the GAC. The functional groups play an important role in the adsorption process and pH has practically no role in this specific case. The FACs have hydrophilic protonated external surfaces in particular, along with the functional surface sites capable to make complexes with the CrO4(2-) and HCrO4(-) present. Surface complex formation is maximized in the order FAC-HNO3>FAC-HF>FAC-HCl, in proportion to the total surface acidity. This is also confirmed by the well-known pseudo second-order kinetic model. Physi-sorption equilibrium isotherms are parameterized by using standard Freundlich and Langmuir models. Langmuir fits better. The formation of surface complexes with the functional groups and hexavalent chromium is also revealed in the images of field emission scanning electron micrograph; energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy analysis after adsorption. The intra-particle diffusion is not the only rate-controlling factor. The Boyd's film diffusion model fits very well with R(2) as high as 98.1% for FAC-HNO3. This result demonstrates that the functionalization of the GAC by acid treatments would increase the diffusion rate, predominantly with a boundary layer diffusion effect. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Chromatic aberration, accommodation, and color preference in asthenopia.

    PubMed

    Drew, Stefanie A; Borsting, Eric; Stark, Lawrence R; Chase, Chris

    2012-07-01

    Asthenopia is a common problem associated with near work and reports suggest that colored lenses or overlays may be applied to reduce symptoms. In this study, we examine the relationship between eyestrain, color preferences, and function of the accommodation and vergence system. Specifically, we examine whether symptomatic observers select colors that reduce accommodative demand based on longitudinal chromatic aberration (LCA). Forty-seven undergraduate students participated in this study. Visual discomfort symptoms were assessed using the Conlon survey. A Mark 2 Intuitive Colorimeter was used to obtain optimal colored light preferences. LCA was modeled using the Chromatic Eye and spectral power density data. A comprehensive evaluation of accommodation and vergence was performed following standard procedures. A significant negative correlation (r = -0.51) was found between eyestrain symptoms and the International Commission on Illumination (CIE) v' axis of colors preferences. Additionally, a significant negative correlation (r = -0.31) was found between eyestrain symptoms and LCA accommodation. Two thirds of the participants in the high discomfort group chose colors that decreased accommodative demand. Accommodative amplitude and vergence facility also correlated with LCA, accounting for 25% of the variance. The color preferences of individuals are systematically influenced by the functioning of their accommodation and vergence systems with increased symptomatology resulting in color selections that reduce LCA accommodative stimulus demand.

  15. Chromate content versus particle size for aircraft paints.

    PubMed

    LaPuma, Peter T; Rhodes, Brian S

    2002-12-01

    Many industries rely on the corrosion inhibiting properties of chromate-containing primer paints to protect metal from oxidation. However, chromate contains hexavalent chromium (Cr(6+)), a known human carcinogen. The concentration of Cr(6+) as a function of paint particle size has important implications to worker health and environmental release from paint facilities. This research examines Cr(6+) content as a function of particle size for three types of aircraft primer paints: solvent-based epoxy-polyamide, water-based epoxy-polyamide, and solvent-based polyurethane. Cascade impactors were used to collect and separate paint particles based on their aerodynamic diameter, from 0.7 to 34.1 microm. The mass of the dry paint collected at each stage was determined and an atomic absorption spectrometer was used to analyze for Cr(6+) content. For all three paints, particles less than 7.0 microm contained disproportionately less Cr(6+) per mass of dry paint than larger particles, and the Cr(6+)concentration decreased substantially as particle size decreased. The smallest particles, 0.7 to 1.0 microm, contained approximately 10% of the Cr(6+) content, per mass of dry paint, compared to particles larger than 7.0 microm. The paint gun settings of air to paint ratio was found to have no influence on the Cr(6+) bias.

  16. Adolescents with current major depressive disorder show dissimilar patterns of age-related differences in ACC and thalamus

    PubMed Central

    Hagan, Cindy C.; Graham, Julia M.E.; Tait, Roger; Widmer, Barry; van Nieuwenhuizen, Adrienne O.; Ooi, Cinly; Whitaker, Kirstie J.; Simas, Tiago; Bullmore, Edward T.; Lennox, Belinda R.; Sahakian, Barbara J.; Goodyer, Ian M.; Suckling, John

    2015-01-01

    Objective There is little understanding of the neural system abnormalities subserving adolescent major depressive disorder (MDD). In a cross-sectional study we compare currently unipolar depressed with healthy adolescents to determine if group differences in grey matter volume (GMV) were influenced by age and illness severity. Method Structural neuroimaging was performed on 109 adolescents with current MDD and 36 healthy controls, matched for age, gender, and handedness. GMV differences were examined within the anterior cingulate cortex (ACC) and across the whole-brain. The effects of age and self-reported depressive symptoms were also examined in regions showing significant main or interaction effects. Results Whole-brain voxel based morphometry revealed no significant group differences. At the whole-brain level, both groups showed a main effect of age on GMV, although this effect was more pronounced in controls. Significant group-by-age interactions were noted: A significant regional group-by-age interaction was observed in the ACC. GMV in the ACC showed patterns of age-related differences that were dissimilar between adolescents with MDD and healthy controls. GMV in the thalamus showed an opposite pattern of age-related differences in adolescent patients compared to healthy controls. In patients, GMV in the thalamus, but not the ACC, was inversely related with self-reported depressive symptoms. Conclusions The depressed adolescent brain shows dissimilar age-related and symptom-sensitive patterns of GMV differences compared with controls. The thalamus and ACC may comprise neural markers for detecting these effects in youth. Further investigations therefore need to take both age and level of current symptoms into account when disaggregating antecedent neural vulnerabilities for MDD from the effects of MDD on the developing brain. PMID:25685707

  17. Adolescents with current major depressive disorder show dissimilar patterns of age-related differences in ACC and thalamus.

    PubMed

    Hagan, Cindy C; Graham, Julia M E; Tait, Roger; Widmer, Barry; van Nieuwenhuizen, Adrienne O; Ooi, Cinly; Whitaker, Kirstie J; Simas, Tiago; Bullmore, Edward T; Lennox, Belinda R; Sahakian, Barbara J; Goodyer, Ian M; Suckling, John

    2015-01-01

    There is little understanding of the neural system abnormalities subserving adolescent major depressive disorder (MDD). In a cross-sectional study we compare currently unipolar depressed with healthy adolescents to determine if group differences in grey matter volume (GMV) were influenced by age and illness severity. Structural neuroimaging was performed on 109 adolescents with current MDD and 36 healthy controls, matched for age, gender, and handedness. GMV differences were examined within the anterior cingulate cortex (ACC) and across the whole-brain. The effects of age and self-reported depressive symptoms were also examined in regions showing significant main or interaction effects. Whole-brain voxel based morphometry revealed no significant group differences. At the whole-brain level, both groups showed a main effect of age on GMV, although this effect was more pronounced in controls. Significant group-by-age interactions were noted: A significant regional group-by-age interaction was observed in the ACC. GMV in the ACC showed patterns of age-related differences that were dissimilar between adolescents with MDD and healthy controls. GMV in the thalamus showed an opposite pattern of age-related differences in adolescent patients compared to healthy controls. In patients, GMV in the thalamus, but not the ACC, was inversely related with self-reported depressive symptoms. The depressed adolescent brain shows dissimilar age-related and symptom-sensitive patterns of GMV differences compared with controls. The thalamus and ACC may comprise neural markers for detecting these effects in youth. Further investigations therefore need to take both age and level of current symptoms into account when disaggregating antecedent neural vulnerabilities for MDD from the effects of MDD on the developing brain.

  18. Copper and Copper Proteins in Parkinson's Disease

    PubMed Central

    Rivera-Mancia, Susana; Diaz-Ruiz, Araceli; Tristan-Lopez, Luis; Rios, Camilo

    2014-01-01

    Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology. PMID:24672633

  19. Regulation of extracellular copper-binding proteins in copper-resistant and copper-sensitive mutants of Vibrio alginolyticus.

    PubMed Central

    Harwood, V J; Gordon, A S

    1994-01-01

    Extracellular proteins of wild-type Vibrio alginolyticus were compared with those of copper-resistant and copper-sensitive mutants. One copper-resistant mutant (Cu40B3) constitutively produced an extracellular protein with the same apparent molecular mass (21 kDa) and chromatographic behavior as copper-binding protein (CuBP), a copper-induced supernatant protein which has been implicated in copper detoxification in wild-type V. alginolyticus. Copper-sensitive V. alginolyticus mutants displayed a range of alterations in supernatant protein profiles. CuBP was not detected in supernatants of one copper-sensitive mutant after cultures had been stressed with 50 microM copper. Increased resistance to copper was not induced by preincubation with subinhibitory levels of copper in the wild type or in the copper-resistant mutant Cu40B3. Copper-resistant mutants maintained the ability to grow on copper-amended agar after 10 or more subcultures on nonselective agar, demonstrating the stability of the phenotype. A derivative of Cu40B3 with wild-type sensitivity to copper which no longer constitutively expressed CuBP was isolated. The simultaneous loss of both constitutive CuBP production and copper resistance in Cu40B3 indicates that constitutive CuBP production is necessary for copper resistance in this mutant. These data support the hypothesis that the extracellular, ca. 20-kDa protein(s) of V. alginolyticus is an important factor in survival and growth of the organism at elevated copper concentrations. The range of phenotypes observed in copper-resistant and copper-sensitive V. alginolyticus indicate that altered sensitivity to copper was mediated by a variety of physiological changes. Images PMID:8031076

  20. [A novel gene (Aa-accA ) encoding acetyl-CoA carboxyltransferase alpha-subunit of Alkalimonas amylolytica N10 enhances salt and alkali tolerance of Escherichia coli and tobacco BY-2 cells].

    PubMed

    Xian, Mingjie; Zhai, Lei; Zhong, Naiqin; Ma, Yiwei; Xue, Yanfen; Ma, Yanhe

    2013-08-04

    Acetyl-CoA carboxylase (ACC) catalyzes the first step of fatty acid synthesis. In most bacteria, ACC is composed of four subunits encoded by accA, accB, accC, and accD. Of them, accA encodes acetyl-CoA carboxyltransferase alpha-subunit. Our prior work on proteomics of Alkalimonas amylolytica N10 showed that the expression of the Aa-accA has a remarkable response to salt and alkali stress. This research aimed to find out the Aa-accA gene contributing to salt and alkali tolerance. The Aa-accA was amplified by PCR from A. amylolytica N10 and expressed in E. coli K12 host. The effects of Aa-accA expression on the growth of transgenic strains were examined under different NaCl concentration and pH conditions. Transgenic tobacco BY-2 cells harboring Aa-accA were also generated via Agrobacterium-mediated transformation. The viability of BY-2 cells was determined with FDA staining method after salt and alkali shock. The Aa-accA gene product has 318 amino acids and is homologous to the carboxyl transferase domain of acyl-CoA carboxylases. It showed 76% identity with AccA (acetyl-CoA carboxylase carboxyltransferase subunit alpha) from E. coli. Compared to the wild-type strains, transgenic E. coli K12 strain containing Aa-accA showed remarkable growth superiority when grown in increased NaCl concentrations and pH levels. The final cell density of the transgenic strains was 2.6 and 3.5 times higher than that of the control type when they were cultivated in LB medium containing 6% (W/V) NaCl and at pH 9, respectively. Complementary expression of Aa-accA in an accA-depletion E. coli can recover the tolerance of K12 delta accA to salt and alkali stresses to some extent. Similar to the transgenic E. coli, transgenic tobacco BY-2 cells showed higher percentages of viability compared to the wild BY-2 cells under the salt or alkali stress condition. We found that Aa-accA from A. amylolytica N10 overexpression enhances the tolerance of both transgenic E. coli and tobacco BY-2 cells to

  1. Post-column reaction for simultaneous analysis of chromatic and leuco forms of malachite green and crystal violet by high-performance liquid chromatography with photometric detection

    USGS Publications Warehouse

    Allen, J.L.; Meinertz, J.R.

    1991-01-01

    The chromatic and leuco forms of malachite green and crystal violet were readily separated and detected by a sensitive and selective high-performance liquid chromatographic procedure. The chromatic and leuco forms of the dyes were separated within 11 min on a C18 column with a mobile phase of 0.05 M sodium acetate and 0.05 M acetic acid in water (19%) and methanol (81%). A reaction chamber, containing 10% PbO2 in Celite 545, was placed between the column and the spectrophotometric detector to oxidize the leuco forms of the dyes to their chromatic forms. Chromatic and leuco malachite green were quantified by their absorbance at 618 nm; and chromatic and leuco Crystal Violet by their absorbance at 588 nm. Detection limits for chromatic and leuco forms of both dyes ranged from 0.12 to 0.28 ng. A linear range of 1 to 100 ng was established for both forms of the dyes.

  2. Chromatic Image Analysis For Quantitative Thermal Mapping

    NASA Technical Reports Server (NTRS)

    Buck, Gregory M.

    1995-01-01

    Chromatic image analysis system (CIAS) developed for use in noncontact measurements of temperatures on aerothermodynamic models in hypersonic wind tunnels. Based on concept of temperature coupled to shift in color spectrum for optical measurement. Video camera images fluorescence emitted by phosphor-coated model at two wavelengths. Temperature map of model then computed from relative brightnesses in video images of model at those wavelengths. Eliminates need for intrusive, time-consuming, contact temperature measurements by gauges, making it possible to map temperatures on complex surfaces in timely manner and at reduced cost.

  3. Spectrally resolved chromatic confocal interferometry for one-shot nano-scale surface profilometry with several tens of micrometric depth range

    NASA Astrophysics Data System (ADS)

    Chen, Liang-Chia; Chen, Yi-Shiuan; Chang, Yi-Wei; Lin, Shyh-Tsong; Yeh, Sheng Lih

    2013-01-01

    In this research, new nano-scale measurement methodology based on spectrally-resolved chromatic confocal interferometry (SRCCI) was successfully developed by employing integration of chromatic confocal sectioning and spectrally-resolve white light interferometry (SRWLI) for microscopic three dimensional surface profilometry. The proposed chromatic confocal method (CCM) using a broad band while light in combination with a specially designed chromatic dispersion objective is capable of simultaneously acquiring multiple images at a large range of object depths to perform surface 3-D reconstruction by single image shot without vertical scanning and correspondingly achieving a high measurement depth range up to hundreds of micrometers. A Linnik-type interferometric configuration based on spectrally resolved white light interferometry is developed and integrated with the CCM to simultaneously achieve nanoscale axis resolution for the detection point. The white-light interferograms acquired at the exit plane of the spectrometer possess a continuous variation of wavelength along the chromaticity axis, in which the light intensity reaches to its peak when the optical path difference equals to zero between two optical arms. To examine the measurement accuracy of the developed system, a pre-calibrated accurate step height target with a total step height of 10.10 μm was measured. The experimental result shows that the maximum measurement error was verified to be less than 0.3% of the overall measuring height.

  4. Chromatic-aberration-corrected diffractive lenses for ultra-broadband focusing

    DOE PAGES

    Wang, Peng; Mohammad, Nabil; Menon, Rajesh

    2016-02-12

    We exploit the inherent dispersion in diffractive optics to demonstrate planar chromatic-aberration-corrected lenses. Specifically, we designed, fabricated and characterized cylindrical diffractive lenses that efficiently focus the entire visible band (450 nm to 700 nm) onto a single line. These devices are essentially pixelated, multi-level microstructures. Experiments confirm an average optical efficiency of 25% for a three-wavelength apochromatic lens whose chromatic focus shift is only 1.3 μm and 25 μm in the lateral and axial directions, respectively. Super-achromatic performance over the continuous visible band is also demonstrated with averaged lateral and axial focus shifts of only 1.65 μm and 73.6 μm,more » respectively. These lenses are easy to fabricate using single-step grayscale lithography and can be inexpensively replicated. Furthermore, these devices are thin (<3 μm), error tolerant, has low aspect ratio (<1:1) and offer polarization-insensitive focusing, all significant advantages compared to alternatives that rely on metasurfaces. Lastly, our design methodology offers high design flexibility in numerical aperture and focal length, and is readily extended to 2D.« less

  5. [Effect of five kinds of pigments on the chromaticity of dental zirconia ceramic].

    PubMed

    Huang, Hui; Zheng, Yuan-li; Zhang, Fu-qiang; Sun, Jing; Gao, Lian

    2007-08-01

    All-ceramic dental restorations should match the colour of the natural teeth in order to fulfill aesthetic demands. The goal of this study was to evaluate the colouration of zirconia ceramic by adding five kinds of pigments. The influence of the pigments concentrations on the chromaticity were also analysed. Different concentrations of five kinds of pigments were added on zirconia powder, then compacted at 200MPa using cold isostatic pressure, sintered to 1400 degrees centigrade and hold for two hours. The chromaticity of sintered bodies were measured with chroma meter. The colours achieved by the different pigments were presented in the CIELab system. The a* value increased with the added amount of Er(2)O(3), while b* value raised with the increasing amount of CeO(2) and Pr(6)O(11). However, three pigments failed to decrease L* value and the sintered body looked too bright. The sintered bodies were brown when adding Fe(2)O(3) to zirconia. Adding MnO2 could decrease the L* value of sintered bodies significantly, but had little influence on the a* and b* value. Five kinds of colorized zirconia ceramic could cover with the chromaticity range of dental ceramic which necessitate further investigation.

  6. Potential U.S. Population Impact of the 2017 ACC/AHA High Blood Pressure Guideline.

    PubMed

    Muntner, Paul; Carey, Robert M; Gidding, Samuel; Jones, Daniel W; Taler, Sandra J; Wright, Jackson T; Whelton, Paul K

    2018-01-16

    The 2017 American College of Cardiology/American Heart Association (ACC/AHA) Guideline for the Prevention, Detection, Evaluation and Management of High Blood Pressure in Adults provides recommendations for the definition of hypertension, systolic and diastolic blood pressure (BP) thresholds for initiation of antihypertensive medication, and BP target goals. This study sought to determine the prevalence of hypertension, implications of recommendations for antihypertensive medication, and prevalence of BP above the treatment goal among U.S. adults using criteria from the 2017 ACC/AHA guideline and the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7). The authors analyzed data from the 2011 to 2014 National Health and Nutrition Examination Survey (N = 9,623). BP was measured 3 times following a standardized protocol and averaged. Results were weighted to produce U.S. population estimates. According to the 2017 ACC/AHA and JNC7 guidelines, the crude prevalence of hypertension among U.S. adults was 45.6% (95% confidence interval [CI]: 43.6% to 47.6%) and 31.9% (95% CI: 30.1% to 33.7%), respectively, and antihypertensive medication was recommended for 36.2% (95% CI: 34.2% to 38.2%) and 34.3% (95% CI: 32.5% to 36.2%) of U.S. adults, respectively. Nonpharmacological intervention is advised for the 9.4% of U.S. adults with hypertension who are not recommended for antihypertensive medication according to the 2017 ACC/AHA guideline. Among U.S. adults taking antihypertensive medication, 53.4% (95% CI: 49.9% to 56.8%) and 39.0% (95% CI: 36.4% to 41.6%) had BP above the treatment goal according to the 2017 ACC/AHA and JNC7 guidelines, respectively. Compared with the JNC7 guideline, the 2017 ACC/AHA guideline results in a substantial increase in the prevalence of hypertension, a small increase in the percentage of U.S. adults recommended for antihypertensive medication, and more intensive BP

  7. Chromatic correction for a VIS-SWIR zoom lens using optical glasses

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Williams, Daniel J. L.; McCarthy, Peter; Visconti, Anthony J.; Bentley, Julie L.; Moore, Duncan T.

    2015-09-01

    With the advancement in sensors, hyperspectral imaging in short wave infrared (SWIR 0.9 μm to 1.7 μm) now has wide applications, including night vision, haze-penetrating imaging, etc. Most conventional optical glasses can be material candidates for designing in the SWIR as they transmit up to 2.2 μm. However, since SWIR is in the middle of the glasses' major absorption wavebands in UV and IR, the flint glasses in SWIR are less dispersive than in the visible spectrum. As a result, the glass map in the SWIR is highly compressed, with crowns and flints all clustering together. Thus correcting for chromatic aberration is more challenging in the SWIR, since the Abbé number ratio of the same glass combination is reduced. Conventionally, fluorides, such as CaF2 and BaF2, are widely used in designing SWIR system due to their unique dispersion properties, even though they are notorious for poor manufacturability or even high toxicity. For lens elements in a zoom system, the ray bundle samples different sections of the each lens aperture as the lens zooms. This creates extra uncertainty in correcting chromatic aberrations. This paper focuses on using only commercially available optical glasses to color-correct a 3X dual-band zoom lens system in the VIS-SWIR. The design tools and techniques are detailed in terms of material selections to minimize the chromatic aberrations in such a large spectrum band and all zoom positions. Examples are discussed for designs with different aperture stop locations, which considerably affect the material choices.

  8. Application of chromatic confocal displacement sensor in measurement of tip clearance

    NASA Astrophysics Data System (ADS)

    Bi, Chao; Li, Di; Fang, Jianguo; Zhang, Bin

    2016-10-01

    In the field of aeronautics, the tip clearance of rotor exerts a crucial influence on the performance of the aero engine. As defined as the radial distance between the top of the blade and the inner wall of the casing, the tip clearance of too large or small size will adversely affect the normal running of the engine. In order to realize accurate measurement of the tip clearance in a simple way, a non-contact measuring method by the chromatic confocal displacement sensor is proposed in the paper. The sensor possesses the advantages such as small volume, good signal-to-noise ratio, high accuracy and response frequency etc., which make it be widely used in engineering and industry. For testing the performance and potential application of the sensor, a simulation testing platform is established. In the platform, a simulation blisk is installed on the air bearing spindle and a chromatic confocal displacement sensor is fixed on the platform to measure the displacement variation of the blade tip, which can be used to characterize the variation of the tip clearance. In the simulation experiments, both of single and continuous measurement of the tip clearance of the 36 blades on the blisk is executed. As the results of experiments show, the chromatic confocal displacement sensor can meet the requirements of measuring task, in which both of high measuring efficiency and accuracy could be achieved. Therefore, the measuring method proposed in the paper can be utilized in the actual assembling sites of the aero engine.

  9. Primary Prevention With Statins: ACC/AHA Risk-Based Approach Versus Trial-Based Approaches to Guide Statin Therapy.

    PubMed

    Mortensen, Martin B; Afzal, Shoaib; Nordestgaard, Børge G; Falk, Erling

    2015-12-22

    Guidelines recommend initiating primary prevention for atherosclerotic cardiovascular disease (ASCVD) with statins based on absolute ASCVD risk assessment. Recently, alternative trial-based and hybrid approaches were suggested for statin treatment eligibility. This study compared these approaches in a direct head-to-head fashion in a contemporary population. The study used the CGPS (Copenhagen General Population Study) with 37,892 subjects aged 40 to 75 years recruited in 2003 to 2008, all free of ASCVD, diabetes, and statin use at baseline. Among the population studied, 42% were eligible for statin therapy according to the 2013 American College of Cardiology/American Heart Association (ACC/AHA) risk assessment and cholesterol treatment guidelines approach, versus 56% with the trial-based approach and 21% with the hybrid approach. Among these statin-eligible subjects, the ASCVD event rate per 1,000 person-years was 9.8, 6.8, and 11.2, respectively. The ACC/AHA-recommended absolute risk score was well calibrated around the 7.5% 10-year ASCVD risk treatment threshold and discriminated better than the trial-based or hybrid approaches. Compared with the ACC/AHA risk-based approach, the net reclassification index for eligibility for statin therapy among 40- to 75-year-old subjects from the CGPS was -0.21 for the trial-based approach and -0.13 for the hybrid approach. The clinical performance of the ACC/AHA risk-based approach for primary prevention of ASCVD with statins was superior to the trial-based and hybrid approaches. Our results indicate that the ACC/AHA guidelines will prevent more ASCVD events than the trial-based and hybrid approaches, while treating fewer people compared with the trial-based approach. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  10. Identification of vascular patients at very high risk for recurrent cardiovascular events: validation of the current ACC/AHA very high risk criteria.

    PubMed

    van den Berg, M Johanneke; Bhatt, Deepak L; Kappelle, L Jaap; de Borst, Gert J; Cramer, Maarten J; van der Graaf, Yolanda; Steg, Ph Gabriel; Visseren, Frank L J

    2017-11-14

    To validate and assess performance of the current ACC/AHA very high risk criteria in patients with clinically manifest arterial disease. Data were used from the SMART study (n = 7216) and REACH Registry (n = 48 322), two prospective cohorts of patients with manifest atherosclerotic arterial disease. Prevalence and incidence rates of recurrent major adverse cardiovascular events (MACE) were calculated, according to the ACC/AHA VHR criteria (cardiovascular disease combined with diabetes, smoking, dyslipidaemia, and/or recent recurrent coronary events). Performance of the ACC/AHA criteria was compared with single very high risk factors in terms of C-statistics and Net Reclassification Index. All patients were at VHR according to the ESC guidelines (incidence of recurrent MACE in SMART was 2.4/100PY, with 95% CI 2.3-2.5/100PY and in REACH 5.1/100PY with 95% CI 5.0-5.3/100PY). In SMART 57% of the patients were at VHR according to the ACC/AHA criteria (incidence of recurrent MACE 2.7/100PY, 95% CI 2.5-2.9/100PY) and in REACH this was 64% (5.9/100PY, 95% CI 5.7-6.1/100PY). The C-statistic for the ACC/AHA VHR criteria was 0.53 in REACH and 0.54 in SMART. Very high risk factors with comparable or slightly better performance were eGFR < 45, polyvascular disease and age >70 years. Around two third of the patients meeting the ACC/AHA VHR criteria had a predicted 10-year risk of recurrent MACE <30%. The ACC/AHA VHR criteria have limited discriminative power. Identifying patients with clinically manifest arterial disease at VHR for recurrent vascular events using eGFR <45, polyvascular disease, or age >70 years performs as well as the ACC/AHA VHR criteria. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

  11. Implementing New Non-Chromate Coatings Systems (Briefing Charts)

    DTIC Science & Technology

    2011-02-09

    Initiate Cr6+ authorization process for continued Cr6+ use using the form, Authorization to Use Hexavalent Chromium. YES NO • Approval of...Aluminum and magnesium anodizing • Hard Chrome Plating • Type II conversion coating on aluminum alloys under chromated primer • Type II conversion coating...Elimination of Hexavalent Chromium 80% 5% 14% 1% Type II Type III Type IC Type IC Fatigue Critical 50% 50% Type II Type IC FRC-SE (JAX) Fully Integrated FRC

  12. GAD65 Promoter Polymorphism rs2236418 Modulates Harm Avoidance in Women via Inhibition/Excitation Balance in the Rostral ACC.

    PubMed

    Colic, Lejla; Li, Meng; Demenescu, Liliana Ramona; Li, Shija; Müller, Iris; Richter, Anni; Behnisch, Gusalija; Seidenbecher, Constanze I; Speck, Oliver; Schott, Björn H; Stork, Oliver; Walter, Martin

    2018-05-30

    Anxiety disorders are common and debilitating conditions with higher prevalence in women. However, factors that predispose women to anxiety phenotypes are not clarified. Here we investigated potential contribution of the single nucleotide polymorphism rs2236418 in GAD2 gene to changes in regional inhibition/excitation balance, anxiety-like traits, and related neural activity in both sexes. One hundred and five healthy individuals were examined with high-field (7T) multimodal magnetic resonance imaging (MRI); including resting-state functional MRI in combination with assessment of GABA and glutamate (Glu) levels via MR spectroscopy. Regional GABA/Glu levels in anterior cingulate cortex (ACC) subregions were assessed as mediators of gene-personality interaction for the trait harm avoidance and moderation by sex was tested. In AA homozygotes, with putatively lower GAD2 promoter activity, we observed increased intrinsic neuronal activity and higher inhibition/excitation balance in pregenual ACC (pgACC) compared with G carriers. The pgACC drove a significant interaction of genotype, region, and sex, where inhibition/excitation balance was significantly reduced only in female AA carriers. This finding was specific for rs2236418 as other investigated single nucleotide polymorphisms of the GABA synthesis related enzymes ( GAD1 , GAD2 , and GLS ) were not significant. Furthermore, only in women there was a negative association of pgACC GABA/Glu ratios with harm avoidance. A moderated-mediation model revealed that pgACC GABA/Glu also mediated the association between the genotype variant and level of harm avoidance, dependent on sex. Our data thus provide new insights into the neurochemical mechanisms that control emotional endophenotypes in humans and constitute predisposing factors for the development of anxiety disorders in women. SIGNIFICANCE STATEMENT Anxiety disorders are among the most common and burdensome psychiatric disorders, with higher prevalence rates in women

  13. Relationship of Hydrogen Bioavailability to Chromate Reduction in Aquifer Sediments

    PubMed Central

    Marsh, Tamara L.; McInerney, Michael J.

    2001-01-01

    Biological Cr(VI) reduction was studied in anaerobic sediments from an aquifer in Norman, Okla. Microcosms containing sediment and mineral medium were amended with various electron donors to determine those most important for biological Cr(VI) reduction. Cr(VI) (about 340 μM) was reduced with endogenous substrates (no donor), or acetate was added. The addition of formate, hydrogen, and glucose stimulated Cr(VI) reduction compared with reduction in unamended controls. From these sediments, an anaerobic Cr(VI)-utilizing enrichment was obtained that was dependent upon hydrogen for both growth and Cr(VI) reduction. No methane was produced by the enrichment, which reduced about 750 μM Cr(VI) in less than six days. The dissolved hydrogen concentration was used as an indicator of the terminal electron accepting process occurring in the sediments. Microcosms with sediments, groundwater, and chromate metabolized hydrogen to a concentration below the detection limits of the mercury vapor gas chromatograph. In microcosms without chromate, the hydrogen concentration was about 8 nM, a concentration comparable to that under methanogenic conditions. When these microcosms were amended with 500 μM Cr(VI), the dissolved hydrogen concentration quickly fell below the detection limits. These results showed that the hydrogen concentration under chromate-reducing conditions became very low, as low as that reported under nitrate- and manganese-reducing conditions, a result consistent with the free energy changes for these reactions. The utilization of formate, lactate, hydrogen, and glucose as electron donors for Cr(VI) reduction indicates that increasing the availability of hydrogen results in a greater capacity for Cr(VI) reduction. This conclusion is supported by the existence of an enrichment dependent upon hydrogen for growth and Cr(VI) reduction. PMID:11282599

  14. Individual and age-related variation in chromatic contrast adaptation

    PubMed Central

    Elliott, Sarah L.; Werner, John S.; Webster, Michael A.

    2012-01-01

    Precortical color channels are tuned primarily to the LvsM (stimulation of L and M cones varied, but S cone stimulation held constant) or SvsLM (stimulation of S cones varied, but L and M cone stimulation held constant) cone-opponent (cardinal) axes, but appear elaborated in the cortex to form higher-order mechanisms tuned to both cardinal and intermediate directions. One source of evidence for these higher-order mechanisms has been the selectivity of color contrast adaptation for noncardinal directions, yet the degree of this selectivity has varied widely across the small sample of observers tested in previous studies. This study explored the possible bases for this variation, and in particular tested whether it reflected age-related changes in the distribution or tuning of color mechanisms. Observers included 15 younger (18–22 years of age) and 15 older individuals (66–82), who adapted to temporal modulations along one of four chromatic axes (two cardinal and two intermediate axes) and then matched the hue and contrast of test stimuli lying along eight different directions in the equiluminant plane. All observers exhibited aftereffects that were selective for both the cardinal and intermediate directions, although selectivity was weaker for the intermediate axes. The degree of selectivity increased with the magnitude of adaptation for all axes, and thus adaptation strength alone may account for much of the variance in selectivity among observers. Older observers showed a stronger magnitude of adaptation thus, surprisingly, more conspicuous evidence for higher-order mechanisms. For both age groups the aftereffects were well predicted by response changes in chromatic channels with linear spectral sensitivities, and there was no evidence for weakened channel tuning with aging. The results suggest that higher-order mechanisms may become more exposed in observers or conditions in which the strength of adaptation is greater, and that both chromatic contrast

  15. HMSN/ACC truncation mutations disrupt brain-type creatine kinase-dependant activation of K+/Cl- co-transporter 3.

    PubMed

    Salin-Cantegrel, Adèle; Shekarabi, Masoud; Holbert, Sébastien; Dion, Patrick; Rochefort, Daniel; Laganière, Janet; Dacal, Sandra; Hince, Pascale; Karemera, Liliane; Gaspar, Claudia; Lapointe, Jean-Yves; Rouleau, Guy A

    2008-09-01

    The potassium-chloride co-transporter 3 (KCC3) is mutated in hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC); however, the molecular mechanisms of HMSN/ACC pathogenesis and the exact role of KCC3 in the development of the nervous system remain poorly understood. The functional regulation of this transporter by protein partners is also largely unknown. Using a yeast two-hybrid approach, we discovered that the C-terminal domain (CTD) of KCC3, which is lost in most HMSN/ACC-causing mutations, directly interacts with brain-specific creatine kinase (CK-B), an ATP-generating enzyme that is also a partner of KCC2. The interaction of KCC3 with CK-B was further confirmed by in vitro glutathione S-transferase pull-down assay, followed by sequencing of the pulled-down complexes. In transfected cultured cells, immunofluorescence labeling showed that CK-B co-localizes with wild-type KCC3, whereas the kinase fails to interact with the inactive truncated KCC3. Finally, CK-B's inhibition by DNFB results in reduction of activity of KCC3 in functional assays using Xenopus laevis oocytes. This physical and functional association between the co-transporter and CK-B is, therefore, the first protein-protein interaction identified to be potentially involved in the pathophysiology of HMSN/ACC.

  16. Theory of chromatic noise masking applied to testing linearity of S-cone detection mechanisms.

    PubMed

    Giulianini, Franco; Eskew, Rhea T

    2007-09-01

    A method for testing the linearity of cone combination of chromatic detection mechanisms is applied to S-cone detection. This approach uses the concept of mechanism noise, the noise as seen by a postreceptoral neural mechanism, to represent the effects of superposing chromatic noise components in elevating thresholds and leads to a parameter-free prediction for a linear mechanism. The method also provides a test for the presence of multiple linear detectors and off-axis looking. No evidence for multiple linear mechanisms was found when using either S-cone increment or decrement tests. The results for both S-cone test polarities demonstrate that these mechanisms combine their cone inputs nonlinearly.

  17. Chromatic Aberration Correction for Atomic Resolution TEM Imaging from 20 to 80 kV.

    PubMed

    Linck, Martin; Hartel, Peter; Uhlemann, Stephan; Kahl, Frank; Müller, Heiko; Zach, Joachim; Haider, Max; Niestadt, Marcel; Bischoff, Maarten; Biskupek, Johannes; Lee, Zhongbo; Lehnert, Tibor; Börrnert, Felix; Rose, Harald; Kaiser, Ute

    2016-08-12

    Atomic resolution in transmission electron microscopy of thin and light-atom materials requires a rigorous reduction of the beam energy to reduce knockon damage. However, at the same time, the chromatic aberration deteriorates the resolution of the TEM image dramatically. Within the framework of the SALVE project, we introduce a newly developed C_{c}/C_{s} corrector that is capable of correcting both the chromatic and the spherical aberration in the range of accelerating voltages from 20 to 80 kV. The corrector allows correcting axial aberrations up to fifth order as well as the dominating off-axial aberrations. Over the entire voltage range, optimum phase-contrast imaging conditions for weak signals from light atoms can be adjusted for an optical aperture of at least 55 mrad. The information transfer within this aperture is no longer limited by chromatic aberrations. We demonstrate the performance of the microscope using the examples of 30 kV phase-contrast TEM images of graphene and molybdenum disulfide, showing unprecedented contrast and resolution that matches image calculations.

  18. Obstructions to the realization of distance graphs with large chromatic numbers on spheres of small radii

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kupavskii, A B; Raigorodskii, A M

    2013-10-31

    We investigate in detail some properties of distance graphs constructed on the integer lattice. Such graphs find wide applications in problems of combinatorial geometry, in particular, such graphs were employed to answer Borsuk's question in the negative and to obtain exponential estimates for the chromatic number of the space. This work is devoted to the study of the number of cliques and the chromatic number of such graphs under certain conditions. Constructions of sequences of distance graphs are given, in which the graphs have unit length edges and contain a large number of triangles that lie on a sphere of radius 1/√3more » (which is the minimum possible). At the same time, the chromatic numbers of the graphs depend exponentially on their dimension. The results of this work strengthen and generalize some of the results obtained in a series of papers devoted to related issues. Bibliography: 29 titles.« less

  19. Effects of longitudinal chromatic aberration on accommodation and emmetropization.

    PubMed

    Seidemann, Anne; Schaeffel, Frank

    2002-09-01

    Less accommodation was found when human subjects read in blue (peak at about 440 nm) than when they read in red light (above 600 nm; [Kroger & Binder, British Journal of Ophthalmology 84 (2000) 890]). On the other hand, emmetropization in chickens did not appear to compensate for the chromatic defocus (385 nm versus 665 nm; [Rohrer, Schaeffel & Zrenner, Journal of Physiology 449 (1992) 363]). The apparently contradictory result was studied in more detail in humans and chickens. Accommodation was measured with an eccentric infrared photorefractor, the PowerRefractor, in human subjects reading under quasi-monochromatic illumination conditions. Chickens were refracted in quasi-monochromatic ambient illumination but with no particular fixation target. In a second experiment, they were also raised in monochromatic light for two days and subsequently refracted both in complete darkness, in monochromatic light, and in white light, both without and with cycloplegia. Consistent with the initial report by Kroger and Binder [British Journal of Ophthalmology 84 (2000) 890], accommodation in human subjects was found to shift in accordance with the chromatic aberration function. An immediate shift in accommodation tonus was also found in the chickens when they were refracted under red and in blue ambient illumination (average difference between refractions in both conditions: 1.26+/-0.54 D, p<0.001 paired t-test). This value is close to the chromatic focus difference between the two wavelengths (1.5 D [Mandelman & Sivak, Vision Research 23 (1983) 1555]). When chickens were raised in blue or red light for two days, and their refractions were subsequently measured in complete darkness, they showed also a difference in refractions (1.41+/-1.00 D; ANOVA: p<0.0012, post hoc t-test: at least p<0.05 among different groups). This difference was no longer significant when they were refracted in white light but became again significant when they were cyclopleged (0.57+/-0.58 D, p=0

  20. Partially dissociable roles of OFC and ACC in stimulus-guided and action-guided decision making.

    PubMed

    Khani, Abbas

    2014-05-01

    Recently, the functional specialization of prefrontal areas of the brain, and, specifically, the functional dissociation of the orbitofrontal cortex (OFC) and the anterior cingulate cortex (ACC), during decision making have become a particular focus of research. A number of neuropsychological and lesion studies have shown that the OFC and ACC have dissociable functions in various dimensions of decision making, which are supported by their different anatomical connections. A recent single-neuron study, however, described a more complex picture of the functional dissociation between these two frontal regions during decision making. Here, I discuss the results of that study and consider alternative interpretations in connection with other findings.

  1. Doctors' knowledge, attitudes, and compliance with 2013 ACC/AHA guidelines for prevention of atherosclerotic cardiovascular disease in Singapore.

    PubMed

    Setia, Sajita; Fung, Selwyn Sze-Wang; Waters, David D

    2015-01-01

    There is an unmet need for strategies to prevent atherosclerotic cardiovascular disease in Singapore. The main objective of this study was to investigate Singapore physicians' response to the 2013 American College of Cardiology and American Heart Association (ACC/AHA) guidelines for treatment of cholesterol and their impact on clinical practice. This survey was conducted in two stages, qualitative and quantitative. Physicians were initially screened on the basis of an initial screener questionnaire, and eligible physicians were then included in the study. Qualitative (n=19) and quantitative (n=66) surveys were completed by eligible physicians from Singapore. Physicians were less familiar with the 2013 ACC/AHA guidelines (35%) as compared with the Singapore Ministry of Health (MoH) lipid guidelines 2006 (49%). Of the physicians whose opinion was sought on the ACC/AHA guidelines, more than 50% disagreed with the definition of high-, moderate-, and low-intensity statin therapy; recommendation of atorvastatin 40-80 mg and rosuvastatin 20-40 mg as medications for high-intensity statin therapy; and classification of individuals who would benefit from moderate- to high-intensity statin therapy. Most physicians assumed that Asians may be intolerant to high-intensity statin therapy. Although embracing the 2013 ACC/AHA guidelines in clinical practice is expected to provide better clinical care to patients, our study revealed high reluctance by physicians, especially in the use of high-dose statins. However, ACC/AHA guidelines can be easily adopted in Asia as there is a wealth of data available for atorvastatin in primary and secondary prevention of atherosclerotic cardiovascular disease with similar efficacy and safety profiles in the white and Asian populations.

  2. The ACC/AHA 2013 pooled cohort equations compared to a Korean Risk Prediction Model for atherosclerotic cardiovascular disease.

    PubMed

    Jung, Keum Ji; Jang, Yangsoo; Oh, Dong Joo; Oh, Byung-Hee; Lee, Sang Hoon; Park, Seong-Wook; Seung, Ki-Bae; Kim, Hong-Kyu; Yun, Young Duk; Choi, Sung Hee; Sung, Jidong; Lee, Tae-Yong; Kim, Sung Hi; Koh, Sang Baek; Kim, Moon Chan; Chang Kim, Hyeon; Kimm, Heejin; Nam, Chungmo; Park, Sungha; Jee, Sun Ha

    2015-09-01

    To evaluate the performance of the American College of Cardiology/American Heart Association (ACC/AHA) 2013 Pooled Cohort Equations in the Korean Heart Study (KHS) population and to develop a Korean Risk Prediction Model (KRPM) for atherosclerotic cardiovascular disease (ASCVD) events. The KHS cohort included 200,010 Korean adults aged 40-79 years who were free from ASCVD at baseline. Discrimination, calibration, and recalibration of the ACC/AHA Equations in predicting 10-year ASCVD risk in the KHS cohort were evaluated. The KRPM was derived using Cox model coefficients, mean risk factor values, and mean incidences from the KHS cohort. In the discriminatory analysis, the ACC/AHA Equations' White and African-American (AA) models moderately distinguished cases from non-cases, and were similar to the KRPM: For men, the area under the receiver operating characteristic curve (AUROCs) were 0.727 (White model), 0.725 (AA model), and 0.741 (KRPM); for women, the corresponding AUROCs were 0.738, 0.739, and 0.745. Absolute 10-year ASCVD risk for men in the KHS cohort was overestimated by 56.5% (White model) and 74.1% (AA model), while the risk for women was underestimated by 27.9% (White model) and overestimated by 29.1% (AA model). Recalibration of the ACC/AHA Equations did not affect discriminatory ability but improved calibration substantially, especially in men in the White model. Of the three ASCVD risk prediction models, the KRPM showed best calibration. The ACC/AHA Equations should not be directly applied for ASCVD risk prediction in a Korean population. The KRPM showed best predictive ability for ASCVD risk. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. Doctors’ knowledge, attitudes, and compliance with 2013 ACC/AHA guidelines for prevention of atherosclerotic cardiovascular disease in Singapore

    PubMed Central

    Setia, Sajita; Fung, Selwyn Sze-Wang; Waters, David D

    2015-01-01

    Purpose There is an unmet need for strategies to prevent atherosclerotic cardiovascular disease in Singapore. The main objective of this study was to investigate Singapore physicians’ response to the 2013 American College of Cardiology and American Heart Association (ACC/AHA) guidelines for treatment of cholesterol and their impact on clinical practice. Methods This survey was conducted in two stages, qualitative and quantitative. Physicians were initially screened on the basis of an initial screener questionnaire, and eligible physicians were then included in the study. Results Qualitative (n=19) and quantitative (n=66) surveys were completed by eligible physicians from Singapore. Physicians were less familiar with the 2013 ACC/AHA guidelines (35%) as compared with the Singapore Ministry of Health (MoH) lipid guidelines 2006 (49%). Of the physicians whose opinion was sought on the ACC/AHA guidelines, more than 50% disagreed with the definition of high-, moderate-, and low-intensity statin therapy; recommendation of atorvastatin 40–80 mg and rosuvastatin 20–40 mg as medications for high-intensity statin therapy; and classification of individuals who would benefit from moderate- to high-intensity statin therapy. Most physicians assumed that Asians may be intolerant to high-intensity statin therapy. Conclusion Although embracing the 2013 ACC/AHA guidelines in clinical practice is expected to provide better clinical care to patients, our study revealed high reluctance by physicians, especially in the use of high-dose statins. However, ACC/AHA guidelines can be easily adopted in Asia as there is a wealth of data available for atorvastatin in primary and secondary prevention of atherosclerotic cardiovascular disease with similar efficacy and safety profiles in the white and Asian populations. PMID:26082642

  4. Mentoring in 2 + 2 Programs: LISD/ACC 2 + 2 Articulation Project.

    ERIC Educational Resources Information Center

    Center for Occupational Research and Development, Inc., Waco, TX.

    The role of mentoring in the 2 + 2 Instrumentation and Control (I&C) articulation project between the Leander Independent School District (LISD) and Austin Community College (ACC) is discussed in this document. Following a brief history of the origin and function of the mentor, the paper explains the need for the mentoring system in the I&C…

  5. Accurate chromatic control and color rendering optimization in LED lighting systems using junction temperature feedback

    NASA Astrophysics Data System (ADS)

    Sisto, Marco Michele; Gauvin, Jonny

    2014-09-01

    Accurate color control of LED lighting systems is a challenging task: noticeable chromaticity shifts are commonly observed in mixed-color and phosphor converted LEDs due to intensity dimming. Furthermore, the emitted color varies with the LED temperature. We present a novel color control method for tri-chromatic and tetra-chromatic LEDs, which enable to set and maintain the LED emission at a target color, or combination of correlated color temperature (CCT) and intensity. The LED color point is maintained over variations in the LED junctions' temperatures and intensity dimming levels. The method does not require color feedback sensors, so to minimize system complexity and cost, but relies on estimation of the LED junctions' temperatures from the junction voltages. If operated with tetra-chromatic LEDs, the method allows meeting an additional optimization criterion: for example, the maximization of a color rendering metric like the Color Rendering Index (CRI) or the Color Quality Scale (CQS), thus providing a high quality and clarity of colors on the surface illuminated by the LED. We demonstrate the control of a RGBW LED at target D65 white point with CIELAB color difference metric triangle;a,bE < 1 for simultaneous variations of flux from approximately 30 lm to 100 lm and LED heat sink temperature from 25°C to 58°C. In the same conditions, we demonstrate a CCT error <1%. Furthermore, the method allows varying the LED CCT from 5500K to 8000K while maintaining luminance within 1% of target. Further work is ongoing to evaluate the stability of the method over LED aging.

  6. Sound the Alarm: The Effect of Narcissism on Retaliatory Aggression is Moderated by dACC Reactivity to Rejection

    PubMed Central

    Chester, David S.; DeWall, C. Nathan

    2015-01-01

    Objective Narcissists behave aggressively when their egos are threatened by interpersonal insults. This effect has been explained in terms of narcissist’s motivation to reduce the discrepancy between their grandiose self and its threatened version, though no research has directly tested this hypothesis. If this notion is true, the link between narcissism and retaliatory aggression should be moderated by neural structures that subserve discrepancy detection, such as the dorsal anterior cingulate cortex (dACC). This study tested the hypothesis that narcissism would only predict greater retaliatory aggression in response to social rejection when the dACC was recruited by the threat. Method Thirty participants (15 females; MAge=18.86, SD=1.25; 77% White) completed a trait narcissism inventory, were socially accepted and then rejected while undergoing fMRI, and then could behave aggressively towards one of the rejecters by blasting them with unpleasant noise. Results When narcissists displayed greater dACC activation during rejection, they behaved aggressively. But there was only a weak or nonsignificant relation between narcissism and aggression among participants with a blunted dACC response. Conclusions Narcissism’s role in aggressive retaliation to interpersonal threats is likely determined by the extent to which the brain’s discrepancy detector registers the newly-created gap between the grandiose and threatened selves. PMID:25564936

  7. Parametric modulation of reward sequences during a reversal task in ACC and VMPFC but not amygdala and striatum.

    PubMed

    Becker, Michael P I; Nitsch, Alexander M; Hewig, Johannes; Miltner, Wolfgang H R; Straube, Thomas

    2016-12-01

    Several regions of the frontal cortex interact with striatal and amygdala regions to mediate the evaluation of reward-related information and subsequent adjustment of response choices. Recent theories discuss the particular relevance of dorsal anterior cingulate cortex (dACC) for switching behavior; consecutively, ventromedial prefrontal cortex (VMPFC) is involved in mediating exploitative behaviors by tracking reward values unfolding after the behavioral switch. Amygdala, on the other hand, has been implied in coding the valence of stimulus-outcome associations and the ventral striatum (VS) has consistently been shown to code a reward prediction error (RPE). Here, we used fMRI data acquired in humans during a reversal task to parametrically model different sequences of positive feedback in order to unravel differential contributions of these brain regions to the tracking and exploitation of rewards. Parameters from an Optimal Bayesian Learner accurately predicted the divergent involvement of dACC and VMPFC during feedback processing: dACC signaled the first, but not later, presentations of positive feedback, while VMPFC coded trial-by-trial accumulations in reward value. Our results confirm that dACC carries a prominent confirmatory signal during processing of first positive feedback. Amygdala coded positive feedbacks more uniformly, while striatal regions were associated with RPE. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Identification of a melatonin receptor type 1A gene ( AccMTNR1A) in Apis cerana cerana and its possible involvement in the response to low temperature stress

    NASA Astrophysics Data System (ADS)

    Li, Guilin; Zhang, Yanming; Ni, Yong; Wang, Ying; Xu, Baohua; Guo, Xingqi

    2018-04-01

    It is known that melatonin plays an indispensable role in the defense against some environment-induced stresses. The melatonin receptor (MTNR) is also closely linked to the environmental stress response in mammals. However, little is known about the function of the MTNR in insects, including honeybees. In this study, we identified a MTNR from Apis cerana cerana named AccMTNR1A, which contained a typical seven-transmembrane domain common to this family of receptors. A subcellular localization analysis showed that AccMTNR1A was localized in the cytomembrane. Additionally, we found that cold stress apparently boosted AccMTNR1A transcription, indicating that AccMTNR1A possibly connects to the cold stress response. The knockdown of AccMTNR1A attenuated the expression level of some genes associated with the cold stress response, suggesting that AccMTNR1A likely plays an analogous role with these genes during low temperature stress response. Moreover, silencing of AccMTNR1A also suppressed the transcription of some antioxidant genes, prompting the possibility that the response of AccMTNR1A to cold stress response may be related to antioxidant signaling pathways. Collectively, the findings presented here provide evidence that AccMTNR1A may play essential roles in protecting Apis cerana cerana from cold stress.

  9. Comparison of the ACC/AHA and Framingham algorithms to assess cardiovascular risk in HIV-infected patients.

    PubMed

    Pinto Neto, Lauro Ferreira da Silva; Dias, Fernanda Rezende; Bressan, Flavia Feres; Santos, Carolina Rocio Oliveira

    The aim of this study was to compare the predictions of Framingham cardiovascular (CV) risk score (FRS) and the American College of Cardiology/American Heart Association (ACC/AHA) risk score in an HIV outpatient clinic in the city of Vitoria, Espirito Santo, Brazil. In a cross-sectional study 341 HIV infected patients over 40 years old consecutively recruited were interviewed. Cohen's kappa coefficient was used to assess agreement between the two algorithms. 61.3% were stratified as low risk by Framingham score, compared with 54% by ACC/AHA score (Spearman correlation 0.845; p<0.000). Only 26.1% were classified as cardiovascular high risk by Framingham compared to 46% by ACC/AHA score (Kappa=0.745; p<0.039). Only one out of eight patients had cardiovascular high risk by Framingham at the time of a myocardial infarction event registered up to five years before the study period. Both cardiovascular risk scores but especially Framingham underestimated high-risk patients in this HIV-infected population. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

  10. Longitudinal measurement of chromatic dispersion along an optical fiber transmission system with a new correction factor

    NASA Astrophysics Data System (ADS)

    Abbasi, Madiha; Imran Baig, Mirza; Shafique Shaikh, Muhammad

    2013-12-01

    At present existence OTDR based techniques have become a standard practice for measuring chromatic dispersion distribution along an optical fiber transmission link. A constructive measurement technique has been offered in this paper, in which a four wavelength bidirectional optical time domain reflectometer (OTDR) has been used to compute the chromatic dispersion allocation beside an optical fiber transmission system. To improve the correction factor a novel formulation has been developed, which leads to an enhanced and defined measurement. The investigational outcomes obtained are in good harmony.

  11. Applicability of the 2013 ACC/AHA Risk Assessment and Cholesterol Treatment Guidelines in the real world: results from a multiethnic case-control study.

    PubMed

    Magnoni, Marco; Berteotti, Martina; Norata, Giuseppe Danilo; Limite, Luca Rosario; Peretto, Giovanni; Cristell, Nicole; Maseri, Attilio; Cianflone, Domenico

    2016-01-01

    The 2013 ACC/AHA cholesterol treatment guidelines have introduced a new cardiovascular risk assessment approach (PCE) and have revisited the threshold for prescribing statins. This study aims to compare the ex ante application of the ACC/AHA and the ATP-III guideline models by using a multiethnic case-control study. ATP-III-FRS and PCE were assessed in 739 patients with first STEMI and 739 age- and gender-matched controls; the proportion of cases and controls that would have been eligible for statin as primary prevention therapy and the discriminatory ability of both models were evaluated. The application of the ACC/AHA compared to the ATP-III model, resulted in an increase in sensitivity [94% (95%CI: 91%-95%) vs. 65% (61%-68%), p< 0.0001], a reduction in specificity [19% (15%-22%) vs. 55% (51%-59%), p< 0.0001] with similar global accuracy [0.56 (0.53-0.59) vs.0.59 (0.57-0.63), p ns]. When stratifying for ethnicity, the accuracy of the ACC/AHA model was higher in Europeans than in Chinese (p = 0.003) and to identified premature STEMI patients within Europeans much better compared to the ATP-III model (p = 0.0289). The application of the ACC/AHA model resulted in a significant reduction of first STEMI patients who would have escaped from preventive treatment. Age and ethnicity affected the accuracy of the ACC/AHA model improving the identification of premature STEMI among Europeans only. Key messages According to the ATP-III guideline model, about one-third of patients with STEMI would not be eligible for primary preventive treatment before STEMI. The application of the new ACC/AHA cholesterol treatment guideline model leads to a significant reduction of the percentage of patients with STEMI who would have been considered at lower risk before the STEMI. The global accuracy of the new ACC/AHA model is higher in the Europeans than in the Chinese and, moreover, among the Europeans, the application of the new ACC/AHA guideline model also improved

  12. Simultaneous speciation analysis of chromate, molybdate, tungstate and vanadate in welding fume alkaline extracts by HPLC-ICP-MS.

    PubMed

    Ščančar, Janez; Berlinger, Balázs; Thomassen, Yngvar; Milačič, Radmila

    2015-09-01

    A novel analytical procedure was developed for the simultaneous speciation analysis of chromate, molybdate, tungstate and vanadate by anion-exchange high performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Linear gradient elution from 100% water to 100% 0.7 M NaCl was applied for chromatographic separation of metal species. In standard aqueous solution at neutral pH molybdate, tungstate and vanadate exist in several aqueous species, while chromate is present as a single CrO4(2-) species. Consequently, only chromate can be separated from this solution in a sharp chromatographic peak. For obtaining sharp chromatographic peaks for molybdate, tungstate and vanadate, the pH of aqueous standard solutions was raised to 12. At highly alkaline conditions single CrO4(2-), MoO4(2-) and WO4(2-) are present and were eluted in sharp chromatographic peaks, while VO4(3-) species, which predominates at pH 12 was eluted in slightly broaden peak. In a mixture of aqueous standard solutions (pH 12) chromate, molybdate, tungstate and vanadate were eluted at retention times from 380 to 420 s, 320 to 370 s, 300 to 350 s and 240 to 360 s, respectively. Eluted species were simultaneously detected on-line by ICP-MS recording m/z 52, 95, 182 and 51. The developed procedure was successfully applied to the analysis of leachable concentrations of chromate, molybdate, tungstate and vanadate in alkaline extracts (2% NaOH+3% Na2CO3) of manual metal arc (MMA) welding fumes loaded on filters. Good repeatability and reproducibility of measurement (RSD±3.0%) for the investigated species were obtained in both aqueous standard solutions (pH 12) and in alkaline extracts of welding fumes. Low limits of detection (LODs) were found for chromate (0.02 ng Cr mL(-1)), molybdate (0.1 ng Mo mL(-1)), tungstate (0.1 ng W mL(-1)) and vanadate (0.2 ng V mL(-1)). The accuracy of analytical procedure for the determination of chromate was checked by analysis of

  13. Carbonate mineralization via an amorphous calcium carbonate (ACC) pathway: Tuning polymorph selection by Mg, pH, and mixing environment

    NASA Astrophysics Data System (ADS)

    Dove, P. M.; Blue, C.; Mergelsberg, S. T.; Giuffre, A. J.; Han, N.; De Yoreo, J. J.

    2017-12-01

    Mineral formation by nonclassical processes is widespread with many pathways that include aggregation of nanoparticles, oriented attachment of fully formed crystals, and sequential nucleation/transformation of amorphous phases (De Yoreo et al., 2015, Science). Field observations indicate amorphous calcium carbonate (ACC) can be the initial precipitate when local conditions promote high supersaturations for short time periods. Examples include microbial mats, marine porewaters that undergo pulses of increased alkalinity, closed basin lakes, and sabkhas. The crystalline products exhibit diverse morphologies and complex elemental and isotopic signatures. This study quantifies relationships between solution composition and the crystalline polymorphs that transform from ACC (Blue et al., GCA, 2017). Our experimental design synthesized ACC under controlled conditions for a suite of compositions by tuning input pH, Mg/Ca, and total carbonate concentration. ACC products were allowed to transform within output suspensions under stirred or quiescent mixing while characterizing the polymorph and composition of evolving solutions and solids. We find that ACC transforms to crystalline polymorphs with a systematic relationship to solution composition to give a quantitative framework based upon solution aMg2+/aCa2+ and aCO32-/aCa2+. We also measure a polymorph-specific evolution of pH and Mg/Ca during the transformation that indicates the initial polymorph to form. Pathway is further modulated by stirring versus quiescent conditions. The findings reconcile discrepancies among previous studies of ACC to crystalline products and supports claims that monohydrocalcite may be an overlooked, transient phase during formation of some aragonite and calcite deposits. Organic additives and extreme pH are not required to tune composition and polymorph. Insights from this study reiterate the need to revisit long-standing dogmas regarding controls on CaCO3 polymorph selection. Classical models

  14. Thiol-based copper handling by the copper chaperone Atox1.

    PubMed

    Hatori, Yuta; Inouye, Sachiye; Akagi, Reiko

    2017-04-01

    Human antioxidant protein 1 (Atox1) plays a crucial role in cellular copper homeostasis. Atox1 captures cytosolic copper for subsequent transfer to copper pumps in trans Golgi network, thereby facilitating copper supply to various copper-dependent oxidereductases matured within the secretory vesicles. Atox1 and other copper chaperones handle cytosolic copper using Cys thiols which are ideal ligands for coordinating Cu(I). Recent studies demonstrated reversible oxidation of these Cys residues in copper chaperones, linking cellular redox state to copper homeostasis. Highlighted in this review are unique redox properties of Atox1 and other copper chaperones. Also, summarized are the redox nodes in the cytosol which potentially play dominant roles in the redox regulation of copper chaperones. © 2016 IUBMB Life, 69(4):246-254, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

  15. GATEWAY Report Brief: Tunable-White Lighting at the ACC Care Center

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None, None

    Summary of a GATEWAY program report that documented the performance of tunable-white LED lighting systems installed in several spaces within the ACC Care Center, a senior-care facility in Sacramento, CA. The project results included energy savings and improved lighting quality, as well as other possible health-related benefits that may have been attributable, at least in part, to the lighting changes.

  16. Cone photoreceptor sensitivities and unique hue chromatic responses: correlation and causation imply the physiological basis of unique hues.

    PubMed

    Pridmore, Ralph W

    2013-01-01

    This paper relates major functions at the start and end of the color vision process. The process starts with three cone photoreceptors transducing light into electrical responses. Cone sensitivities were once expected to be Red Green Blue color matching functions (to mix colors) but microspectrometry proved otherwise: they instead peak in yellowish, greenish, and blueish hues. These physiological functions are an enigma, unmatched with any set of psychophysical (behavioral) functions. The end-result of the visual process is color sensation, whose essential percepts are unique (or pure) hues red, yellow, green, blue. Unique hues cannot be described by other hues, but can describe all other hues, e.g., that hue is reddish-blue. They are carried by four opponent chromatic response curves but the literature does not specify whether each curve represents a range of hues or only one hue (a unique) over its wavelength range. Here the latter is demonstrated, confirming that opponent chromatic responses define, and may be termed, unique hue chromatic responses. These psychophysical functions also are an enigma, unmatched with any physiological functions or basis. Here both enigmas are solved by demonstrating the three cone sensitivity curves and the three spectral chromatic response curves are almost identical sets (Pearson correlation coefficients r from 0.95-1.0) in peak wavelengths, curve shapes, math functions, and curve crossover wavelengths, though previously unrecognized due to presentation of curves in different formats, e.g., log, linear. (Red chromatic response curve is largely nonspectral and thus derives from two cones.) Close correlation combined with deterministic causation implies cones are the physiological basis of unique hues. This match of three physiological and three psychophysical functions is unique in color vision.

  17. Evaluation of layered zinc hydroxide nitrate and zinc/nickel double hydroxide salts in the removal of chromate ions from solutions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bortolaz de Oliveira, Henrique; Wypych, Fernando, E-mail: wypych@ufpr.br

    Layered zinc hydroxide nitrate (ZnHN) and Zn/Ni layered double hydroxide salts were synthesized and used to remove chromate ions from solutions at pH 8.0. The materials were characterized by many instrumental techniques before and after chromate ion removal. ZnHN decomposed after contact with the chromate solution, whereas the layered structure of Zn/Ni hydroxide nitrate (Zn/NiHN) and Zn/Ni hydroxide acetate (Zn/NiHA) remained their layers intact after the topotactic anionic exchange reaction, only changing the basal distances. ZnHN, Zn/NiHN, and Zn/NiHA removed 210.1, 144.8, and 170.1 mg of CrO{sub 4}{sup 2−}/g of material, respectively. Although the removal values obtained for Zn/NiHN andmore » Zn/NiHA were smaller than the values predicted for the ideal formulas of the solids (194.3 and 192.4 mg of CrO{sub 4}{sup 2−}/g of material, respectively), the measured capacities were higher than the values achieved with many materials reported in the literature. Kinetic experiments showed the removal reaction was fast. To facilitate the solid/liquid separation process after chromium removal, Zn/Ni layered double hydroxide salts with magnetic supports were also synthesized, and their ability to remove chromate was evaluated. - Highlights: • Zinc hydroxide nitrate and Zn/Ni hydroxide nitrate or acetate were synthesized. • The interlayer anions were replaced by chromate anions at pH=8.0. • Only Zn/Ni hydroxide nitrate or acetate have the structure preserved after exchange. • Fast exchange reaction and high capacity of chromate removal were observed. • Magnetic materials were obtained to facilitate the solids removal the from solutions.« less

  18. Electrocoat Process for Non-Chromate Primers in DoD Manufacturing

    DTIC Science & Technology

    2011-02-01

    requirements are uniquely  suited for aerospace  aluminum. ↑ O2 ↑ H2 Anode (+) Cathode (-) Deposited Film Alkaline  clean Rinse ElectrocoatSurface...Objectives ● Demonstration and validation of a novel, non‐chromated,  environmentally friendly,  electrodeposited  primer. ● The primers will be

  19. RELATIVE LEACHING AND AQUATIC TOXICITY OF PRESSURE-TREATED WOOD PRODUCTS USING BATCH LEACHING TESTS

    EPA Science Inventory

    Samples of southern yellow pine dimensional lumber, each treated with one of five different waterborne chemical preservatives, were leached using 18-hour batch leaching tests. The wood preservatives included chromated copper arsenate (CCA), alkaline copper quaternary (ACQ), coppe...

  20. Influence of chromatic aberrations on space charge ion optics.

    PubMed

    Whealton, J H; Tsai, C C

    1978-04-01

    By solution to the Poisson-Vlasov equation the influence of fluctuations (chromatic aberrations) on ion optics is shown for various accelerator designs : (1) cylindrical bore triode with various aspect ratios, (2) pseudo-Pierce shaped electrode triode at various aspect ratios, (3) insulated coating emission electrode triode for various preacceleration potentials, and (4) cylindrical bore tetrodes for various field distributions. Fluctuation levels of 20% can be very important in limiting the ion optics in certain cases.

  1. Sound the Alarm: The Effect of Narcissism on Retaliatory Aggression Is Moderated by dACC Reactivity to Rejection.

    PubMed

    Chester, David S; DeWall, C Nathan

    2016-06-01

    Narcissists behave aggressively when their egos are threatened by interpersonal insults. This effect has been explained in terms of narcissists' motivation to reduce the discrepancy between their grandiose self and its threatened version, though no research has directly tested this hypothesis. If this notion is true, the link between narcissism and retaliatory aggression should be moderated by neural structures that subserve discrepancy detection, such as the dorsal anterior cingulate cortex (dACC). This study tested the hypothesis that narcissism would only predict greater retaliatory aggression in response to social rejection when the dACC was recruited by the threat. Thirty participants (15 females; Mage  = 18.86, SD = 1.25; 77% White) completed a trait narcissism inventory, were socially accepted and then rejected while undergoing fMRI, and then could behave aggressively toward one of the rejecters by blasting him or her with unpleasant noise. When narcissists displayed greater dACC activation during rejection, they behaved aggressively. But there was only a weak or nonsignificant relation between narcissism and aggression among participants with a blunted dACC response. Narcissism's role in aggressive retaliation to interpersonal threats is likely determined by the extent to which the brain's discrepancy detector registers the newly created gap between the grandiose and threatened selves. © 2015 Wiley Periodicals, Inc.

  2. ACCE Study Tour to ISTE2011 (San Francisco, New York, Washington, Philadelphia)

    ERIC Educational Resources Information Center

    Gronn, Donna; Romeo, Geoff

    2011-01-01

    In June/July this year a group of 28 educators from across Australia travelled to the US on the 2011 ACCE ISTE Study Tour. The group comprised a very broad section of educators--primary, secondary and tertiary classroom teachers, ICT coordinators, managers, private consultants and regional office managers. The government, catholic and independent…

  3. How effective are the ESC/EAS and 2013 ACC/AHA guidelines in treating dyslipidemia? Lessons from a lipid clinic.

    PubMed

    Barkas, Fotios; Milionis, Haralampos; Kostapanos, Michael S; Mikhailidis, Dimitri P; Elisaf, Moses; Liberopoulos, Evangelos

    2015-02-01

    There is a paucity of data regarding the attainment of lipid-lowering treatment goals according to the recent American College of Cardiology/American Heart Association (ACC/AHA) guidelines. The aim of the present study was to assess how applicable these 2013 recommendations are in the setting of an Outpatient University Hospital Lipid Clinic. This was a retrospective (from 1999 to 2013) observational study including 1000 consecutive adults treated for hyperlipidemia and followed up for ≥3 years. Comparisons for the applicability of current European Society of Cardiology/European Atherosclerosis Society (ESC/EAS) and recent ACC/AHA guidelines were performed. Achievement rates of low density lipoprotein cholesterol (LDL-C) targets set by ESC/EAS were 21%, 44% and 62% among patients at very high, high and moderate cardiovascular risk, respectively, receiving statin monotherapy. Among individuals on high-intensity statins only 47% achieved the anticipated ≥50% LDL-C reduction, i.e. the ACC/AHA target. The corresponding rate was significantly greater among those on statin + ezetimibe (76%, p < 0.05). Likewise, higher rates of LDL-C target attainment according to ESC/EAS guidelines were observed in patients on statin + ezetimibe compared with statin monotherapy (37, 50 and 71% for the three risk groups, p < 0.05 for the very high risk group). The application of the ACC/AHA guidelines may be associated with undertreatment of high risk patients due to suboptimal LDL-C response to high-intensity statins in clinical practice. Adding ezetimibe substantially increases the rate of the ESC/EAS LDL-C target achievement together with the rate of LDL-C lowering response suggested by the ACC/AHA.

  4. The Allende multicompound chondrule (ACC)—Chondrule formation in a local super-dense region of the early solar system

    NASA Astrophysics Data System (ADS)

    Bischoff, Addi; Wurm, Gerhard; Chaussidon, Marc; Horstmann, Marian; Metzler, Knut; Weyrauch, Mona; Weinauer, Julia

    2017-05-01

    In Allende, a very complex compound chondrule (Allende compound chondrule; ACC) was found consisting of at least 16 subchondrules (14 siblings and 2 independents). Its overall texture can roughly be described as a barred olivine object (BO). The BO texture is similar in all siblings, but does not exist in the two independents, which appear as relatively compact olivine-rich units. Because of secondary alteration of pristine Allende components and the ACC in particular, only limited predictions can be made concerning the original compositions of the colliding melt droplets. Based on textural and mineralogical characteristics, the siblings must have been formed on a very short time scale in a dense, local environment. This is also supported by oxygen isotope systematics showing similar compositions for all 16 subchondrules. Furthermore, the ACC subchondrules are isotopically distinct from typical Allende chondrules, indicating formation in or reaction with a more 16O-poor reservoir. We modeled constraints on the particle density required at the ACC formation location, using textural, mineral-chemical, and isotopic observations on this multicompound chondrule to define melt droplet collision conditions. In this context, we discuss the possible relationship between the formation of complex chondrules and the formation of macrochondrules and cluster chondrites. While macrochondrules may have formed under similar or related conditions as complex chondrules, cluster chondrites certainly require different formation conditions. Cluster chondrites represent a mixture of viscously deformed, seemingly young chondrules of different chemical and textural types and a population of older chondrules. Concerning the formation of ACC calculations suggest the existence of very local, kilometer-sized, and super-dense chondrule-forming regions with extremely high solid-to-gas mass ratios of 1000 or more.

  5. Toxicity of sodium chromate and 3,4-dichloroaniline to crustaceans

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    van der Meer, C.; Teunissen, C.; Boog, T.F.M.

    1988-02-01

    Small adult and larval crustaceans are important components of a number of food webs. Therefore, it is important on the one hand to determine the sensitivity of these crustaceans to environmental contaminants and on the other hand to select the most sensitive species as test organisms to help establish the permissible contamination. In brackish water adults as well as larvae of the species Palaemonetes pugio and Uca pugilator have been most frequently investigated. These species can also be studied in sea water. The marine species Carcinus maenas, Crangon septemspinosa and Homarus americanus have also been studied relatively intensively. The presentmore » paper describes the toxicity, at different salinities, of Na/sub 2/, CrO/sub 4/, (chromate) and 3,4-dichloroaniline (3,4-DCA) to a number of relatively small adult and larval crustaceans. Chromate was chosen as a model of a heavy metal since, although its toxicity may be relatively low, it may under certain circumstance have considerable environmental effects. Moreover, bichromate has been recommended as a standard in Daphnia tests. 3,4-dichloroaniline was chosen as a model of a chlorinated hydrocarbon, the handling of which does not need special precautions.« less

  6. Statistical interpretation of chromatic indicators in correlation to phytochemical profile of a sulfur dioxide-free mulberry (Morus nigra) wine submitted to non-thermal maturation processes.

    PubMed

    Tchabo, William; Ma, Yongkun; Kwaw, Emmanuel; Zhang, Haining; Xiao, Lulu; Apaliya, Maurice T

    2018-01-15

    The four different methods of color measurement of wine proposed by Boulton, Giusti, Glories and Commission International de l'Eclairage (CIE) were applied to assess the statistical relationship between the phytochemical profile and chromatic characteristics of sulfur dioxide-free mulberry (Morus nigra) wine submitted to non-thermal maturation processes. The alteration in chromatic properties and phenolic composition of non-thermal aged mulberry wine were examined, aided by the used of Pearson correlation, cluster and principal component analysis. The results revealed a positive effect of non-thermal processes on phytochemical families of wines. From Pearson correlation analysis relationships between chromatic indexes and flavonols as well as anthocyanins were established. Cluster analysis highlighted similarities between Boulton and Giusti parameters, as well as Glories and CIE parameters in the assessment of chromatic properties of wines. Finally, principal component analysis was able to discriminate wines subjected to different maturation techniques on the basis of their chromatic and phenolics characteristics. Copyright © 2017. Published by Elsevier Ltd.

  7. Tuning the light in senior care: Evaluating a trial LED lighting system at the ACC Care Center in Sacramento, CA

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Davis, Robert G.; Wilkerson, Andrea M.

    This report summarizes the results from a trial installation of light-emitting diode (LED) lighting systems in several spaces within the ACC Care Center in Sacramento, CA. The Sacramento Municipal Utility District (SMUD) coordinated the project and invited the U.S. Department of Energy (DOE) to document the performance of the LED lighting systems as part of a GATEWAY evaluation. DOE tasked the Pacific Northwest National Laboratory (PNNL) to conduct the investigation. SMUD and ACC staff coordinated and completed the design and installation of the LED systems, while PNNL and SMUD staff evaluated the photometric performance of the systems. ACC staff alsomore » track behavioral and health measures of the residents; some of those results are reported here, although PNNL staff were not directly involved in collecting or interpreting those data. The trial installation took place in a double resident room and a single resident room, and the corridor that connects those (and other) rooms to the central nurse station. Other spaces in the trial included the nurse station, a common room called the family room located near the nurse station, and the ACC administrator’s private office.« less

  8. Reduced AMPK-ACC and mTOR signaling in muscle from older men, and effect of resistance exercise

    PubMed Central

    Li, Mengyao; Verdijk, Lex B.; Sakamoto, Kei; Ely, Brian; van Loon, Luc J.C.; Musi, Nicolas

    2012-01-01

    AMP-activated protein kinase (AMPK) is a key energy-sensitive enzyme that controls numerous metabolic and cellular processes. Mammalian target of rapamycin (mTOR) is another energy/nutrient-sensitive kinase that controls protein synthesis and cell growth. In this study we determined whether older versus younger men have alterations in the AMPK and mTOR pathways in skeletal muscle, and examined the effect of a long term resistance type exercise training program on these signaling intermediaries. Older men had decreased AMPKα2 activity and lower phosphorylation of AMPK and its downstream signaling substrate acetyl-CoA carboxylase (ACC). mTOR phosphylation also was reduced in muscle from older men. Exercise training increased AMPKα1 activity in older men, however, AMPKα2 activity, and the phosphorylation of AMPK, ACC and mTOR, were not affected. In conclusion, older men have alterations in the AMPK-ACC and mTOR pathways in muscle. In addition, prolonged resistance type exercise training induces an isoform-selective up regulation of AMPK activity. PMID:23000302

  9. Reduced AMPK-ACC and mTOR signaling in muscle from older men, and effect of resistance exercise.

    PubMed

    Li, Mengyao; Verdijk, Lex B; Sakamoto, Kei; Ely, Brian; van Loon, Luc J C; Musi, Nicolas

    2012-01-01

    AMP-activated protein kinase (AMPK) is a key energy-sensitive enzyme that controls numerous metabolic and cellular processes. Mammalian target of rapamycin (mTOR) is another energy/nutrient-sensitive kinase that controls protein synthesis and cell growth. In this study we determined whether older versus younger men have alterations in the AMPK and mTOR pathways in skeletal muscle, and examined the effect of a long term resistance type exercise training program on these signaling intermediaries. Older men had decreased AMPKα2 activity and lower phosphorylation of AMPK and its downstream signaling substrate acetyl-CoA carboxylase (ACC). mTOR phosphylation also was reduced in muscle from older men. Exercise training increased AMPKα1 activity in older men, however, AMPKα2 activity, and the phosphorylation of AMPK, ACC and mTOR, were not affected. In conclusion, older men have alterations in the AMPK-ACC and mTOR pathways in muscle. In addition, prolonged resistance type exercise training induces an isoform-selective up regulation of AMPK activity. Published by Elsevier Ireland Ltd.

  10. Precursors for formation of copper selenide, indium selenide, copper indium diselenide, and/or copper indium gallium diselenide films

    DOEpatents

    Curtis, Calvin J; Miedaner, Alexander; Van Hest, Maikel; Ginley, David S

    2014-11-04

    Liquid-based precursors for formation of Copper Selenide, Indium Selenide, Copper Indium Diselenide, and/or copper Indium Galium Diselenide include copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent. These liquid-based precursors can be deposited in liquid form onto substrates and treated by rapid thermal processing to form crystalline copper selenide and indium selenide films.

  11. Automated thermal mapping techniques using chromatic image analysis

    NASA Technical Reports Server (NTRS)

    Buck, Gregory M.

    1989-01-01

    Thermal imaging techniques are introduced using a chromatic image analysis system and temperature sensitive coatings. These techniques are used for thermal mapping and surface heat transfer measurements on aerothermodynamic test models in hypersonic wind tunnels. Measurements are made on complex vehicle configurations in a timely manner and at minimal expense. The image analysis system uses separate wavelength filtered images to analyze surface spectral intensity data. The system was initially developed for quantitative surface temperature mapping using two-color thermographic phosphors but was found useful in interpreting phase change paint and liquid crystal data as well.

  12. Copper Metallochaperones

    PubMed Central

    Robinson, Nigel J.; Winge, Dennis R.

    2014-01-01

    The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the CuA and intramembrane CuB sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution. PMID:20205585

  13. Chromatic Modulator for a High-Resolution CCD or APS

    NASA Technical Reports Server (NTRS)

    Hartley, Frank; Hull, Anthony

    2008-01-01

    A chromatic modulator has been proposed to enable the separate detection of the red, green, and blue (RGB) color components of the same scene by a single charge-coupled device (CCD), active-pixel sensor (APS), or similar electronic image detector. Traditionally, the RGB color-separation problem in an electronic camera has been solved by use of either (1) fixed color filters over three separate image detectors; (2) a filter wheel that repeatedly imposes a red, then a green, then a blue filter over a single image detector; or (3) different fixed color filters over adjacent pixels. The use of separate image detectors necessitates precise registration of the detectors and the use of complicated optics; filter wheels are expensive and add considerably to the bulk of the camera; and fixed pixelated color filters reduce spatial resolution and introduce color-aliasing effects. The proposed chromatic modulator would not exhibit any of these shortcomings. The proposed chromatic modulator would be an electromechanical device fabricated by micromachining. It would include a filter having a spatially periodic pattern of RGB strips at a pitch equal to that of the pixels of the image detector. The filter would be placed in front of the image detector, supported at its periphery by a spring suspension and electrostatic comb drive. The spring suspension would bias the filter toward a middle position in which each filter strip would be registered with a row of pixels of the image detector. Hard stops would limit the excursion of the spring suspension to precisely one pixel row above and one pixel row below the middle position. In operation, the electrostatic comb drive would be actuated to repeatedly snap the filter to the upper extreme, middle, and lower extreme positions. This action would repeatedly place a succession of the differently colored filter strips in front of each pixel of the image detector. To simplify the processing, it would be desirable to encode information on

  14. LEACHING OF CCA-TREATED WOOD: IMPLICATIONS FOR WASTE DISPOSAL

    EPA Science Inventory

    Leaching of arsenic, chromium, and copper from chromated copper arsenate (CCA)-treated wood poses possible environmental risk when disposed. Samples of un-weathered CCA-treated wood were tested using a variety of US regulatory leaching procedures, including the toxicity character...

  15. EVALUATING ACQ AS AN ALTERNATIVE WOOD PRESERVATIVE SYSTEM

    EPA Science Inventory

    This evaluation addresses the waste reduction/pollution prevention and economic issues involved in replacing chromated copper arsenate (CCA) with ammoniacal copper/quaternary ammonium (ACQ) as a way to preserve wood. The most obvious pollution prevention benefit gained by using A...

  16. 1-Aminocyclopropane-1-carboxylic acid (ACC) deaminase-containing rhizobacteria protect Ocimum sanctum plants during waterlogging stress via reduced ethylene generation.

    PubMed

    Barnawal, Deepti; Bharti, Nidhi; Maji, Deepamala; Chanotiya, Chandan Singh; Kalra, Alok

    2012-09-01

    Ocimum sanctum grown as rain-fed crop, is known to be poorly adapted to waterlogged conditions. Many a times the crop suffers extreme damages because of anoxia and excessive ethylene generation due to waterlogging conditions present under heavy rain. The usefulness of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase-containing plant growth promoting rhizobacteria was investigated under waterlogging stress. The comparison of herb yield and stress induced biochemical changes of waterlogged and non-waterlogged plants with and without ACC deaminase-containing microbiological treatments were monitored in this study. Ten plant growth promoting rhizobacteria strains containing ACC-deaminase were isolated and characterized. Four selected isolates Fd2 (Achromobacter xylosoxidans), Bac5 (Serratia ureilytica), Oci9 (Herbaspirillum seropedicae) and Oci13 (Ochrobactrum rhizosphaerae) had the potential to protect Ocimum plants from flood induced damage under waterlogged glass house conditions. Pot experiments were conducted to evaluate the potential of these ACC deaminase-containing selected strains for reducing the yield losses caused by waterlogging conditions. Bacterial treatments protected plants from waterlogging induced detrimental changes like stress ethylene production, reduced chlorophyll concentration, higher lipid peroxidation, proline concentration and reduced foliar nutrient uptake. Fd2 (A. xylosoxidans) induced maximum waterlogging tolerance as treated waterlogged plants recorded maximum growth and herb yield (46.5% higher than uninoculated waterlogged plants) with minimum stress ethylene levels (53% lower ACC concentration as compared to waterlogged plants without bacterial inoculation) whereas under normal non-waterlogged conditions O. rhizosphaerae was most effective in plant growth promotion. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  17. Cone Photoreceptor Sensitivities and Unique Hue Chromatic Responses: Correlation and Causation Imply the Physiological Basis of Unique Hues

    PubMed Central

    Pridmore, Ralph W.

    2013-01-01

    This paper relates major functions at the start and end of the color vision process. The process starts with three cone photoreceptors transducing light into electrical responses. Cone sensitivities were once expected to be Red Green Blue color matching functions (to mix colors) but microspectrometry proved otherwise: they instead peak in yellowish, greenish, and blueish hues. These physiological functions are an enigma, unmatched with any set of psychophysical (behavioral) functions. The end-result of the visual process is color sensation, whose essential percepts are unique (or pure) hues red, yellow, green, blue. Unique hues cannot be described by other hues, but can describe all other hues, e.g., that hue is reddish-blue. They are carried by four opponent chromatic response curves but the literature does not specify whether each curve represents a range of hues or only one hue (a unique) over its wavelength range. Here the latter is demonstrated, confirming that opponent chromatic responses define, and may be termed, unique hue chromatic responses. These psychophysical functions also are an enigma, unmatched with any physiological functions or basis. Here both enigmas are solved by demonstrating the three cone sensitivity curves and the three spectral chromatic response curves are almost identical sets (Pearson correlation coefficients r from 0.95–1.0) in peak wavelengths, curve shapes, math functions, and curve crossover wavelengths, though previously unrecognized due to presentation of curves in different formats, e.g., log, linear. (Red chromatic response curve is largely nonspectral and thus derives from two cones.) Close correlation combined with deterministic causation implies cones are the physiological basis of unique hues. This match of three physiological and three psychophysical functions is unique in color vision. PMID:24204755

  18. Advantages and challenges of increased antimicrobial copper use and copper mining.

    PubMed

    Elguindi, Jutta; Hao, Xiuli; Lin, Yanbing; Alwathnani, Hend A; Wei, Gehong; Rensing, Christopher

    2011-07-01

    Copper is a highly utilized metal for electrical, automotive, household objects, and more recently as an effective antimicrobial surface. Copper-containing solutions applied to fruits and vegetables can prevent bacterial and fungal infections. Bacteria, such as Salmonellae and Cronobacter sakazakii, often found in food contamination, are rapidly killed on contact with copper alloys. The antimicrobial effectiveness of copper alloys in the healthcare environment against bacteria causing hospital-acquired infections such as methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli O157:H7, and Clostridium difficile has been described recently. The use of copper and copper-containing materials will continue to expand and may lead to an increase in copper mining and production. However, the copper mining and manufacturing industry and the consumer do not necessarily enjoy a favorable relationship. Open pit mining, copper mine tailings, leaching products, and deposits of toxic metals in the environment often raises concerns and sometimes public outrage. In addition, consumers may fear that copper alloys utilized as antimicrobial surfaces in food production will lead to copper toxicity in humans. Therefore, there is a need to mitigate some of the negative effects of increased copper use and copper mining. More thermo-tolerant, copper ion-resistant microorganisms could improve copper leaching and lessen copper groundwater contamination. Copper ion-resistant bacteria associated with plants might be useful in biostabilization and phytoremediation of copper-contaminated environments. In this review, recent progress in microbiological and biotechnological aspects of microorganisms in contact with copper will be presented and discussed, exploring their role in the improvement for the industries involved as well as providing better environmental outcomes.

  19. How daylight influences high-order chromatic descriptors in natural images.

    PubMed

    Ojeda, Juan; Nieves, Juan Luis; Romero, Javier

    2017-07-01

    Despite the global and local daylight changes naturally occurring in natural scenes, the human visual system usually adapts quite well to those changes, developing a stable color perception. Nevertheless, the influence of daylight in modeling natural image statistics is not fully understood and has received little attention. The aim of this work was to analyze the influence of daylight changes in different high-order chromatic descriptors (i.e., color volume, color gamut, and number of discernible colors) derived from 350 color images, which were rendered under 108 natural illuminants with Correlated Color Temperatures (CCT) from 2735 to 25,889 K. Results suggest that chromatic and luminance information is almost constant and does not depend on the CCT of the illuminant for values above 14,000 K. Nevertheless, differences between the red-green and blue-yellow image components were found below that CCT, with most of the statistical descriptors analyzed showing local extremes in the range 2950 K-6300 K. Uniform regions and areas of the images attracting observers' attention were also considered in this analysis and were characterized by their patchiness index and their saliency maps. Meanwhile, the results of the patchiness index do not show a clear dependence on CCT, and it is remarkable that a significant reduction in the number of discernible colors (58% on average) was found when the images were masked with their corresponding saliency maps. Our results suggest that chromatic diversity, as defined in terms of the discernible colors, can be strongly reduced when an observer scans a natural scene. These findings support the idea that a reduction in the number of discernible colors will guide visual saliency and attention. Whatever the modeling is mediating the neural representation of natural images, natural image statistics, it is clear that natural image statistics should take into account those local maxima and minima depending on the daylight illumination and

  20. Corrosion Finishing/Coating Systems for DoD Metallic Substrates Based on Non-Chromate Inhibitors and UV Curable, Zero VOC Materials

    DTIC Science & Technology

    2010-08-01

    Corrosion resistant coatings containing non-chromate inhibitors and no volatile organic compounds were developed and evaluated for DoD applications...Transmission Electron Microscopy TRI – Toxic Release Inventory UV – Ultraviolet UVAs – Ultraviolet Absorbers VOCs – Volatile Organic Compounds XPS – X...containing non-chromate inhibitors and no volatile organic compounds were developed and evaluated for DoD applications. The technical effort

  1. Copper as a target for prostate cancer therapeutics: copper-ionophore pharmacology and altering systemic copper distribution.

    PubMed

    Denoyer, Delphine; Pearson, Helen B; Clatworthy, Sharnel A S; Smith, Zoe M; Francis, Paul S; Llanos, Roxana M; Volitakis, Irene; Phillips, Wayne A; Meggyesy, Peter M; Masaldan, Shashank; Cater, Michael A

    2016-06-14

    Copper-ionophores that elevate intracellular bioavailable copper display significant therapeutic utility against prostate cancer cells in vitro and in TRAMP (Transgenic Adenocarcinoma of Mouse Prostate) mice. However, the pharmacological basis for their anticancer activity remains unclear, despite impending clinical trails. Herein we show that intracellular copper levels in prostate cancer, evaluated in vitro and across disease progression in TRAMP mice, were not correlative with copper-ionophore activity and mirrored the normal levels observed in patient prostatectomy tissues (Gleason Score 7 & 9). TRAMP adenocarcinoma cells harbored markedly elevated oxidative stress and diminished glutathione (GSH)-mediated antioxidant capacity, which together conferred selective sensitivity to prooxidant ionophoric copper. Copper-ionophore treatments [CuII(gtsm), disulfiram & clioquinol] generated toxic levels of reactive oxygen species (ROS) in TRAMP adenocarcinoma cells, but not in normal mouse prostate epithelial cells (PrECs). Our results provide a basis for the pharmacological activity of copper-ionophores and suggest they are amendable for treatment of patients with prostate cancer. Additionally, recent in vitro and mouse xenograft studies have suggested an increased copper requirement by prostate cancer cells. We demonstrated that prostate adenocarcinoma development in TRAMP mice requires a functional supply of copper and is significantly impeded by altered systemic copper distribution. The presence of a mutant copper-transporting Atp7b protein (tx mutation: A4066G/Met1356Val) in TRAMP mice changed copper-integration into serum and caused a remarkable reduction in prostate cancer burden (64% reduction) and disease severity (grade), abrogating adenocarcinoma development. Implications for current clinical trials are discussed.

  2. Copper as a target for prostate cancer therapeutics: copper-ionophore pharmacology and altering systemic copper distribution

    PubMed Central

    Denoyer, Delphine; Pearson, Helen B.; Clatworthy, Sharnel A.S.; Smith, Zoe M.; Francis, Paul S.; Llanos, Roxana M.; Volitakis, Irene; Phillips, Wayne A.; Meggyesy, Peter M.; Masaldan, Shashank; Cater, Michael A.

    2016-01-01

    Copper-ionophores that elevate intracellular bioavailable copper display significant therapeutic utility against prostate cancer cells in vitro and in TRAMP (Transgenic Adenocarcinoma of Mouse Prostate) mice. However, the pharmacological basis for their anticancer activity remains unclear, despite impending clinical trails. Herein we show that intracellular copper levels in prostate cancer, evaluated in vitro and across disease progression in TRAMP mice, were not correlative with copper-ionophore activity and mirrored the normal levels observed in patient prostatectomy tissues (Gleason Score 7 & 9). TRAMP adenocarcinoma cells harbored markedly elevated oxidative stress and diminished glutathione (GSH)-mediated antioxidant capacity, which together conferred selective sensitivity to prooxidant ionophoric copper. Copper-ionophore treatments [CuII(gtsm), disulfiram & clioquinol] generated toxic levels of reactive oxygen species (ROS) in TRAMP adenocarcinoma cells, but not in normal mouse prostate epithelial cells (PrECs). Our results provide a basis for the pharmacological activity of copper-ionophores and suggest they are amendable for treatment of patients with prostate cancer. Additionally, recent in vitro and mouse xenograft studies have suggested an increased copper requirement by prostate cancer cells. We demonstrated that prostate adenocarcinoma development in TRAMP mice requires a functional supply of copper and is significantly impeded by altered systemic copper distribution. The presence of a mutant copper-transporting Atp7b protein (tx mutation: A4066G/Met1356Val) in TRAMP mice changed copper-integration into serum and caused a remarkable reduction in prostate cancer burden (64% reduction) and disease severity (grade), abrogating adenocarcinoma development. Implications for current clinical trials are discussed. PMID:27175597

  3. Analytical approach to chromatic correction in the final focus system of circular colliders

    DOE PAGES

    Cai, Yunhai

    2016-11-28

    Here, a conventional final focus system in particle accelerators is systematically analyzed. We find simple relations between the parameters of two focus modules in the final telescope. Using the relations, we derive the chromatic Courant-Snyder parameters for the telescope. The parameters are scaled approximately according to (L*/βmore » $$*\\atop{y}$$)δ, where L* is the distance from the interaction point to the first quadrupole, β$$*\\atop{y}$$ the vertical beta function at the interaction point, and δ the relative momentum deviation. Most importantly, we show how to compensate its chromaticity order by order in δ by a traditional correction module flanked by an asymmetric pair of harmonic multipoles. The method enables a circular Higgs collider with 2% momentum aperture and illuminates a path forward to 4% in the future.« less

  4. Complete genome sequence of the chromate-reducing bacterium Thermoanaerobacter thermohydrosulfuricus strain BSB-33

    DOE PAGES

    Bhattacharya, Pamela; Barnebey, Adam; Zemla, Marcin; ...

    2015-10-05

    Thermoanaerobacter thermohydrosulfuricus BSB-33 is a thermophilic gram positive obligate anaerobe isolated from a hot spring in West Bengal, India. Unlike other T. thermohydrosulfuricus strains, BSB-33 is able to anaerobically reduce Fe(III) and Cr(VI) optimally at 60 °C. BSB-33 is the first Cr(VI) reducing T. thermohydrosulfuricus genome sequenced and of particular interest for bioremediation of environmental chromium contaminations. Here we discuss features of T. thermohydrosulfuricus BSB-33 and the unique genetic elements that may account for the peculiar metal reducing properties of this organism. The T. thermohydrosulfuricus BSB-33 genome comprises 2597606 bp encoding 2581 protein genes, 12 rRNA, 193 pseudogenes and hasmore » a G + C content of 34.20 %. Lastly, putative chromate reductases were identified by comparative analyses with other Thermoanaerobacter and chromate-reducing bacteria.« less

  5. Digital halftoning methods for selectively partitioning error into achromatic and chromatic channels

    NASA Technical Reports Server (NTRS)

    Mulligan, Jeffrey B.

    1990-01-01

    A method is described for reducing the visibility of artifacts arising in the display of quantized color images on CRT displays. The method is based on the differential spatial sensitivity of the human visual system to chromatic and achromatic modulations. Because the visual system has the highest spatial and temporal acuity for the luminance component of an image, a technique which will reduce luminance artifacts at the expense of introducing high-frequency chromatic errors is sought. A method based on controlling the correlations between the quantization errors in the individual phosphor images is explored. The luminance component is greatest when the phosphor errors are positively correlated, and is minimized when the phosphor errors are negatively correlated. The greatest effect of the correlation is obtained when the intensity quantization step sizes of the individual phosphors have equal luminances. For the ordered dither algorithm, a version of the method can be implemented by simply inverting the matrix of thresholds for one of the color components.

  6. Advanced Copper Composites Against Copper-Tolerant Xanthomonas perforans and Tomato Bacterial Spot.

    PubMed

    Strayer-Scherer, A; Liao, Y Y; Young, M; Ritchie, L; Vallad, G E; Santra, S; Freeman, J H; Clark, D; Jones, J B; Paret, M L

    2018-02-01

    Bacterial spot, caused by Xanthomonas spp., is a widespread and damaging bacterial disease of tomato (Solanum lycopersicum). For disease management, growers rely on copper bactericides, which are often ineffective due to the presence of copper-tolerant Xanthomonas strains. This study evaluated the antibacterial activity of the new copper composites core-shell copper (CS-Cu), multivalent copper (MV-Cu), and fixed quaternary ammonium copper (FQ-Cu) as potential alternatives to commercially available micron-sized copper bactericides for controlling copper-tolerant Xanthomonas perforans. In vitro, metallic copper from CS-Cu and FQ-Cu at 100 μg/ml killed the copper-tolerant X. perforans strain within 1 h of exposure. In contrast, none of the micron-sized copper rates (100 to 1,000 μg/ml) from Kocide 3000 significantly reduced copper-tolerant X. perforans populations after 48 h of exposure compared with the water control (P < 0.05). All copper-based treatments killed the copper-sensitive X. perforans strain within 1 h. Greenhouse studies demonstrated that all copper composites significantly reduced bacterial spot disease severity when compared with copper-mancozeb and water controls (P < 0.05). Although there was no significant impact on yield, copper composites significantly reduced disease severity when compared with water controls, using 80% less metallic copper in comparison with copper-mancozeb in field studies (P < 0.05). This study highlights the discovery that copper composites have the potential to manage copper-tolerant X. perforans and tomato bacterial spot.

  7. Evaluation of resistance to asiatic citrus canker among selections of pera sweet orange (Citrus sinensis)

    USDA-ARS?s Scientific Manuscript database

    Asiatic citrus canker (ACC, caused by the bacterium Xanthomonas citri subsp. citri) is a destructive disease of citrus in Brazil and in several other citrus-producing countries. ACC management is problematic, and bactericides such as copper can be reasonably efficacious but do not completely control...

  8. Comparative effectiveness of ACC-deaminase and/or nitrogen-fixing rhizobacteria in promotion of maize (Zea mays L.) growth under lead pollution.

    PubMed

    Hassan, Waseem; Bano, Rizwana; Bashir, Farhat; David, Julie

    2014-09-01

    Lead (Pb) pollution is appearing as an alarming threat nowadays. Excessive Pb concentrations in agricultural soils result in minimizing the soil fertility and health which affects the plant growth and leads to decrease in crop production. Plant growth promoting rhizobacteria (PGPR) are beneficial bacteria which can protect the plants against many abiotic stresses, and enhance the growth. The study aimed to identify important rhizobacterial strains by using the 1-aminocyclopropane-1-carboxylate (ACC) enrichment technique and examine their inoculation effects in the growth promotion of maize, under Pb pollution. A pot experiment was conducted and six rhizobacterial isolates were used. Pb was added to 2 kg soil in each pot (with 4 seeds/pot) using Pb(NO3)2 at the rate of 0, 100, 200, 300, and 400 mg kg(-1) Pb with three replications in completely randomized design. Rhizobacterial isolates performed significantly better under all Pb levels, i.e., 100 to 400 Pb mg kg(-1) soil, compared to control. Comparing the efficacy of the rhizobacterial isolates under different Pb levels, rhizobacterial isolates having both ACC-deaminase and nitrogen-fixing activities (AN8 and AN12) showed highest increase in terms of the physical, chemical and enzymatic growth parameters of maize, followed by the rhizobacterial isolates having ACC-deaminase activity only (ACC5 and ACC8), and then the nitrogen-fixing rhizobia (Azotobacter and RN5). However, the AN8 isolate showed maximum efficiency, and highest shoot and root length (14.2 and 6.1 cm), seedling fresh and dry weights (1.91 and 0.14 g), chlorophyll a, b, and carotenoids (24.1, 30.2 and 77.7 μg/l), protein (0.82 mg/g), proline (3.42 μmol/g), glutathione S-transferase, peroxidase and catalase (12.3, 4.2 and 7.2 units/mg protein), while the lowest Pb uptake in the shoot and root (0.83 and 0.48 mg/kg) were observed under this rhizobial isolate at the highest Pb level (i.e., 400 Pb mg kg(-1) soil). The results revealed that PGPR

  9. A Plasmodium falciparum copper-binding membrane protein with copper transport motifs

    PubMed Central

    2012-01-01

    Background Copper is an essential catalytic co-factor for metabolically important cellular enzymes, such as cytochrome-c oxidase. Eukaryotic cells acquire copper through a copper transport protein and distribute intracellular copper using molecular chaperones. The copper chelator, neocuproine, inhibits Plasmodium falciparum ring-to-trophozoite transition in vitro, indicating a copper requirement for malaria parasite development. How the malaria parasite acquires or secretes copper still remains to be fully elucidated. Methods PlasmoDB was searched for sequences corresponding to candidate P. falciparum copper-requiring proteins. The amino terminal domain of a putative P. falciparum copper transport protein was cloned and expressed as a maltose binding fusion protein. The copper binding ability of this protein was examined. Copper transport protein-specific anti-peptide antibodies were generated in chickens and used to establish native protein localization in P. falciparum parasites by immunofluorescence microscopy. Results Six P. falciparum copper-requiring protein orthologs and a candidate P. falciparum copper transport protein (PF14_0369), containing characteristic copper transport protein features, were identified in PlasmoDB. The recombinant amino terminal domain of the transport protein bound reduced copper in vitro and within Escherichia coli cells during recombinant expression. Immunolocalization studies tracked the copper binding protein translocating from the erythrocyte plasma membrane in early ring stage to a parasite membrane as the parasites developed to schizonts. The protein appears to be a PEXEL-negative membrane protein. Conclusion Plasmodium falciparum parasites express a native protein with copper transporter characteristics that binds copper in vitro. Localization of the protein to the erythrocyte and parasite plasma membranes could provide a mechanism for the delivery of novel anti-malarial compounds. PMID:23190769

  10. Chromatic-aberration diagnostic based on a spectrally resolved lateral-shearing interferometer

    DOE PAGES

    Bahk, Seung -Whan; Dorrer, Christopher; Roides, Rick G.; ...

    2016-03-18

    Here, a simple diagnostic characterizing one-dimensional chromatic aberrations in a broadband beam is introduced. A Ronchi grating placed in front of a spectrometer entrance slit provides spectrally coupled spatial phase information. The radial-group delay of a refractive system and the pulse-front delay of a wedged glass plate have been characterized accurately in a demonstration experiment.

  11. Lumen degradation and chromaticity shift in glass and silicone based high-power phosphor-converted white-emitting diodes under thermal tests

    NASA Astrophysics Data System (ADS)

    Cheng, Wood-Hi; Tsai, Chun-Chin; Wang, Jimmy

    2011-10-01

    The lumen degradation and chromaticity shift in glass and silicone based high-power phosphor-converted white-emitting diodes (PC-WLEDs) under accelerated thermal tests at 150°C, 200°C, and 250°C are presented and compared. The glass based PC-WLEDs exhibited better thermal stability than the silicone by 4.8 time reductions in lumen loss 6.8 time reductions in chromaticity shift at 250°C, respectively. The mean-time-to-failure (MTTF) evaluation of glass and silicone based high-power PC-WLEDs in accelerated thermal tests is also presented and compared. The results showed that the glass based PC-WLEDs exhibited higher MTTF than the silicone by 7.53 times in lumen loss and 14.4 times in chromaticity shift at 250°C, respectively. The thermal performance of lumen, chromaticity, and MTTF investigations demonstrated that the thermal stability of the glass based PC-WLEDs were better than the silicone. A better thermal stability phosphor layer of glass as encapsulation material may be beneficial to the many applications where the LED modules with high power and high reliability are demanded.

  12. Delayed Luminance and Chromatic Contrast Sensitivity in Infants with Spontaneously Regressed Retinopathy of Prematurity

    PubMed Central

    Bosworth, Rain; Robbins, Shira L.; Granet, David B.; Dobkins, Karen

    2013-01-01

    Background The current study assessed whether contrast sensitivity is affected in preterm infants with a history of spontaneously regressed retinopathy of prematurity (ROP, Stages 1–3). Specifically, we employed luminance (light/dark) and chromatic (red/green) stimuli, which are mediated by the magnocellular (M) and parvocellular (P) subcortical pathways, respectively. Methods Contrast sensitivity (CS) was measured using forced choice preferential looking testing in 21 infants with a history of ROP and 41 control preterm infants who were born prematurely but did not develop ROP, tested between 8 and 47 weeks (2–11 months) postterm age. Infants were presented with chromatic and luminance drifting sinusoidal gratings, which appeared randomly on the left or right side of the monitor on each trial. The contrast of the stimuli varied across trials and was defined in terms of root mean squared cone contrast for long- and medium-wavelength cones. Results Between 8 and 25 weeks postterm, ROP infants had significantly worse CS, and there was a trend for greater impairment for Luminance than Chromatic CS. This delay was not seen at older ages between 26 and 47 weeks postterm. Conclusions These findings are consistent with the concept that early maturation of the M pathway is vulnerable to biological insult, as in the case of ROP, to a greater extent than is the P pathway. PMID:23744448

  13. Optical frequency-domain chromatic dispersion measurement method for higher-order modes in an optical fiber.

    PubMed

    Ahn, Tae-Jung; Jung, Yongmin; Oh, Kyunghwan; Kim, Dug Young

    2005-12-12

    We propose a new chromatic dispersion measurement method for the higher-order modes of an optical fiber using optical frequency modulated continuous-wave (FMCW) interferometry. An optical fiber which supports few excited modes was prepared for our experiments. Three different guiding modes of the fiber were identified by using far-field spatial beam profile measurements and confirmed with numerical mode analysis. By using the principle of a conventional FMWC interferometry with a tunable external cavity laser, we have demonstrated that the chromatic dispersion of a few-mode optical fiber can be obtained directly and quantitatively as well as qualitatively. We have also compared our measurement results with those of conventional modulation phase-shift method.

  14. Dispersion strengthened copper

    DOEpatents

    Sheinberg, Haskell; Meek, Thomas T.; Blake, Rodger D.

    1989-01-01

    A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

  15. Dispersion strengthened copper

    DOEpatents

    Sheinberg, Haskell; Meek, Thomas T.; Blake, Rodger D.

    1990-01-01

    A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

  16. The 2013 ACC/AHA 10-year atherosclerotic cardiovascular disease risk index is better than SCORE and QRisk II in rheumatoid arthritis: is it enough?

    PubMed

    Ozen, Gulsen; Sunbul, Murat; Atagunduz, Pamir; Direskeneli, Haner; Tigen, Kursat; Inanc, Nevsun

    2016-03-01

    To determine the ability of the new American College of Cardiology and American Heart Association (ACC/AHA) 10-year atherosclerotic cardiovascular disease (ASCVD) risk algorithm in detecting high cardiovascular (CV) risk, RA patients identified by carotid ultrasonography (US) were compared with Systematic Coronary Risk Evaluation (SCORE) and QRisk II algorithms. SCORE, QRisk II, 2013 ACC/AHA 10-year ASCVD risk and EULAR recommended modified versions were calculated in 216 RA patients. In sonographic evaluation, carotid intima-media thickness >0.90 mm and/or carotid plaques were used as the gold standard test for subclinical atherosclerosis and high CV risk (US+). Eleven (5.1%), 15 (6.9%) and 44 (20.4%) patients were defined as having high CV risk according to SCORE, QRisk II and ACC/AHA 10-year ASCVD risk, respectively. Fifty-two (24.1%) patients were US + and of those, 8 (15.4%), 7 (13.5%) and 23 (44.2%) patients were classified as high CV risk according to SCORE, QRisk II and ACC/AHA 10-year ASCVD risk, respectively. The ACC/AHA 10-year ASCVD risk index better identified US + patients than SCORE and QRisk II (P < 0.0001). With EULAR modification, reclassification from moderate to high risk occurred only in two, five and seven patients according to SCORE, QRisk II and ACC/AHA 10-year ASCVD risk, respectively. The 2013 ACC/AHA 10-year ASCVD risk estimator was better than the SCORE and QRisk II indices in RA, but still failed to identify 55% of high risk patients. Furthermore adjustment of threshold and EULAR modification did not work well. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. A preliminary study of preservative retention and penetration in ACQ-treated timbers using near infrared spectroscopy

    Treesearch

    Chi-Leung So; Thomas L. Eberhardt; Stan T. Lebow; Leslie H. Groom

    2006-01-01

    Near infrared (NIR) spectroscopy has been previously used in our laboratory to predict copper, chromium, and arsenic levels in samples of chromated copper arsenate (CCA)-treated wood. In the present study, we utilized our custom-made NIR scanning system, NIRVANA (near infrared visual and automated numerical analysis), to scan cross sections of ACQ (alkaline copper quat...

  18. Chromatic spatial contrast sensitivity estimated by visual evoked cortical potential and psychophysics

    PubMed Central

    Barboni, M.T.S.; Gomes, B.D.; Souza, G.S.; Rodrigues, A.R.; Ventura, D.F.; Silveira, L.C.L.

    2013-01-01

    The purpose of the present study was to measure contrast sensitivity to equiluminant gratings using steady-state visual evoked cortical potential (ssVECP) and psychophysics. Six healthy volunteers were evaluated with ssVECPs and psychophysics. The visual stimuli were red-green or blue-yellow horizontal sinusoidal gratings, 5° × 5°, 34.3 cd/m2 mean luminance, presented at 6 Hz. Eight spatial frequencies from 0.2 to 8 cpd were used, each presented at 8 contrast levels. Contrast threshold was obtained by extrapolating second harmonic amplitude values to zero. Psychophysical contrast thresholds were measured using stimuli at 6 Hz and static presentation. Contrast sensitivity was calculated as the inverse function of the pooled cone contrast threshold. ssVECP and both psychophysical contrast sensitivity functions (CSFs) were low-pass functions for red-green gratings. For electrophysiology, the highest contrast sensitivity values were found at 0.4 cpd (1.95 ± 0.15). ssVECP CSF was similar to dynamic psychophysical CSF, while static CSF had higher values ranging from 0.4 to 6 cpd (P < 0.05, ANOVA). Blue-yellow chromatic functions showed no specific tuning shape; however, at high spatial frequencies the evoked potentials showed higher contrast sensitivity than the psychophysical methods (P < 0.05, ANOVA). Evoked potentials can be used reliably to evaluate chromatic red-green CSFs in agreement with psychophysical thresholds, mainly if the same temporal properties are applied to the stimulus. For blue-yellow CSF, correlation between electrophysiology and psychophysics was poor at high spatial frequency, possibly due to a greater effect of chromatic aberration on this kind of stimulus. PMID:23369980

  19. Formation of copper-indium-selenide and/or copper-indium-gallium-selenide films from indium selenide and copper selenide precursors

    DOEpatents

    Curtis, Calvin J [Lakewood, CO; Miedaner, Alexander [Boulder, CO; Van Hest, Maikel [Lakewood, CO; Ginley, David S [Evergreen, CO; Nekuda, Jennifer A [Lakewood, CO

    2011-11-15

    Liquid-based indium selenide and copper selenide precursors, including copper-organoselenides, particulate copper selenide suspensions, copper selenide ethylene diamine in liquid solvent, nanoparticulate indium selenide suspensions, and indium selenide ethylene diamine coordination compounds in solvent, are used to form crystalline copper-indium-selenide, and/or copper indium gallium selenide films (66) on substrates (52).

  20. Multi-Chromatic Ultrashort Pulse Filamentation and Bulk Modification in Dielectrics

    DTIC Science & Technology

    2016-05-05

    multi -pulse fields 7 6 Filamentation and bulk modification by spatio-temporally chirped pulses 8 7 Quantum modeling of photoionization and nonlinear...pulses. (b) two co-propagating pulses of di↵erent frequencies. 4) Develop non-time-averaged multi -chromatic quantum -mechanical models of photoion- ization...very well with those of the extended multi -rate equation using the relaxation approximation, which is much faster. A continued collaboration to also

  1. Now you see me, now you don't: iridescence increases the efficacy of lizard chromatic signals

    NASA Astrophysics Data System (ADS)

    Pérez i de Lanuza, Guillem; Font, Enrique

    2014-10-01

    The selective forces imposed by primary receivers and unintended eavesdroppers of animal signals often act in opposite directions, constraining the development of conspicuous coloration. Because iridescent colours change their chromatic properties with viewer angle, iridescence offers a potential mechanism to relax this trade-off when the relevant observers involved in the evolution of signal design adopt different viewer geometries. We used reflectance spectrophotometry and visual modelling to test if the striking blue head coloration of males of the lizard Lacerta schreibeiri (1) is iridescent and (2) is more conspicuous when viewed from the perspective of conspecifics than from that of the main predators of adult L. schreibeiri (raptors). We demonstrate that the blue heads of L. schreiberi show angle-dependent changes in their chromatic properties. This variation allows the blue heads to be relatively conspicuous to conspecific viewers located in the same horizontal plane as the sender, while simultaneously being relatively cryptic to birds that see it from above. This study is the first to suggest the use of angle-dependent chromatic signals in lizards, and provides the first evidence of the adaptive function of iridescent coloration based on its detectability to different observers.

  2. Brain-derived neurotrophic factor (BDNF) in the rostral anterior cingulate cortex (rACC) contributes to neuropathic spontaneous pain-related aversion via NR2B receptors.

    PubMed

    Zhang, Le; Wang, Gongming; Ma, Jinben; Liu, Chengxiao; Liu, Xijiang; Zhan, Yufeng; Zhang, Mengyuan

    2016-10-01

    The rostral anterior cingulate cortex (rACC) plays an important role in pain affect. Previous investigations have reported that the rACC mediates the negative affective component of inflammatory pain and contributed to the aversive state of nerve injury-induced neuropathic pain. Brain-derived neurotrophic factor (BDNF), an activity-dependent neuromodulator in the adult brain, is believed to play a role in the development and maintenance of inflammatory and neuropathic pain in the spinal cord. However, whether and how BDNF in the rACC regulates pain-related aversion due to peripheral nerve injury is largely unknown. Behaviorally, using conditioned place preference (CPP) training in rats, which is thought to reveal spontaneous pain-related aversion, we found that CPP was acquired following spinal clonidine in rats with partial sciatic nerve transection. Importantly, BDNF was upregulated within the rACC in of rats with nerve injury and enhanced the CPP acquisition, while a local injection of a BDNF-tropomyosin receptor kinase B (TrkB) antagonist into the rACC completely blocked this process. Finally, we demonstrated that the BDNF/TrkB pathway exerted its function by activating the NR2B receptor, which is widely accepted to be a crucial factor contributing to pain affect. In conclusion, our results demonstrate that the BDNF/TrkB-mediated signaling pathway in the rACC is involved in the development of neuropathic spontaneous pain-related aversion and that this process is dependent upon activation of NR2B receptors. These findings suggest that suppression of the BDNF-related signaling pathway in the rACC may provide a novel strategy to overcome pain-related aversion. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Chromate reduction and heavy metal fixation in soil

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schwitzgebel, K.

    In situ reduction of chromates and the fixation of the metals Cr, Pb, Zn, Cu, Cd and Ni in soil was investigated using Fe II and soluble silica. Fe II fulfills two functions. It reduces chromates (CrVI) at soil pH to CrIII and the reaction products, Fe(OH)[sub 3] and Cr(OH)[sub 3], coprecipitate/adsorb heavy metals. In the absence of CrVI iron is added as FeIII. Destabilized silica also fulfills two functions. It reacts with the metal and metal hydroxides and reduces the soil permeability. The leaching rate (mg/m[sup 2]s) of a metal is the product of leachate flow rate ([ell]/M[sup 2]s)more » and the leachate concentration (mg/[ell]). The leachate flow rate is directly proportional to the hydraulic coefficient (Darcy's Law). Treatment with destabilized silica reduces the hydraulic coefficient of virgin soil (K[sub h] = 10[sup [minus]2]...10[sup [minus]4]) to K[sub h]=10[sup [minus]7] (cm/s) resulting in a flow rate reduction of 3--5 orders of magnitude. Iron plus silica treatment results in a leachate concentration reduction of up to 2 orders of magnitude (Cr:95--99%;Pb:99%;Zn 95--99%; Cd:93--99%; Ni:75--94%). Combined effect of flow rate reduction and leachate concentration reduction results in a potential leaching rate reduction of five to seven orders of magnitude. Iron-silica treatment may be developed into an efficient containment technology, provided the silica gel integrity does not change with time.« less

  4. Human Newborn Color Vision: Measurement with Chromatic Stimuli Varying in Excitation Purity.

    ERIC Educational Resources Information Center

    Adams, Russell J.; Courage, Mary L.

    1998-01-01

    Habituated 180 neonates to white lights of varying luminance and tested for recovery of habituation to green, yellow, or red lights varying in excitation purity. Found that newborns discriminated chromatic stimuli from white only when excitation purity exceeded levels much higher than those for adults. Results reinforce view that neonates' vision…

  5. On the chromatic number of a space with forbidden equilateral triangle

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zvonarev, A E; Raigorodskii, A M; Kharlamova, A A

    2014-09-30

    We improve the Frankl-Rödl estimate for the product of the numbers of edges in uniform hypergraphs with forbidden cardinalities of the intersection of edges. By using this estimate, we obtain explicit bounds for the chromatic number of a space with forbidden monochromatic equilateral triangles. Bibliography: 31 titles.

  6. Retinal image contrast obtained by a model eye with combined correction of chromatic and spherical aberrations

    PubMed Central

    Ohnuma, Kazuhiko; Kayanuma, Hiroyuki; Lawu, Tjundewo; Negishi, Kazuno; Yamaguchi, Takefumi; Noda, Toru

    2011-01-01

    Correcting spherical and chromatic aberrations in vitro in human eyes provides substantial visual acuity and contrast sensitivity improvements. We found the same improvement in the retinal images using a model eye with/without correction of longitudinal chromatic aberrations (LCAs) and spherical aberrations (SAs). The model eye included an intraocular lens (IOL) and artificial cornea with human ocular LCAs and average human SAs. The optotypes were illuminated using a D65 light source, and the images were obtained using two-dimensional luminance colorimeter. The contrast improvement from the SA correction was higher than the LCA correction, indicating the benefit of an aspheric achromatic IOL. PMID:21698008

  7. Thermodynamic Properties of M2EO4, M2Mo x O3 x + 1 and Double Chromates (M = Li, Na, K, Rb, Cs; E = Cr, Mo, W)

    NASA Astrophysics Data System (ADS)

    Suponitskiy, Yu. L.; Zolotova, E. S.; Dyunin, A. G.; Liashenko, S. E.

    2018-03-01

    The phase transition temperatures of chromates and molybdates of certain alkali metals, and the melting temperature and enthalpy of polymorphic transformations for tungstates, are determined by means of thermal analysis. Enthalpies of dissolution of rubidium and cesium chromates in water and enthalpies of dissolution of alkali metal tungstates in a melt at 923 K are measured via calorimetry. Standard enthalpies of formation of sought chromates are calculated. The linear correlations between the enthalpies of formation of sulfates, selenates, chromates, tungstates, and molybdates are established, and a linear correlation within - (Δ G o ox)-1-(Δ MV)ox)-1 coordinates is found for isopolymolybdates.

  8. A comparison of native GPU computing versus OpenACC for implementing flow-routing algorithms in hydrological applications

    NASA Astrophysics Data System (ADS)

    Rueda, Antonio J.; Noguera, José M.; Luque, Adrián

    2016-02-01

    In recent years GPU computing has gained wide acceptance as a simple low-cost solution for speeding up computationally expensive processing in many scientific and engineering applications. However, in most cases accelerating a traditional CPU implementation for a GPU is a non-trivial task that requires a thorough refactorization of the code and specific optimizations that depend on the architecture of the device. OpenACC is a promising technology that aims at reducing the effort required to accelerate C/C++/Fortran code on an attached multicore device. Virtually with this technology the CPU code only has to be augmented with a few compiler directives to identify the areas to be accelerated and the way in which data has to be moved between the CPU and GPU. Its potential benefits are multiple: better code readability, less development time, lower risk of errors and less dependency on the underlying architecture and future evolution of the GPU technology. Our aim with this work is to evaluate the pros and cons of using OpenACC against native GPU implementations in computationally expensive hydrological applications, using the classic D8 algorithm of O'Callaghan and Mark for river network extraction as case-study. We implemented the flow accumulation step of this algorithm in CPU, using OpenACC and two different CUDA versions, comparing the length and complexity of the code and its performance with different datasets. We advance that although OpenACC can not match the performance of a CUDA optimized implementation (×3.5 slower in average), it provides a significant performance improvement against a CPU implementation (×2-6) with by far a simpler code and less implementation effort.

  9. Simplified projection technique to correct geometric and chromatic lens aberrations using plenoptic imaging.

    PubMed

    Dallaire, Xavier; Thibault, Simon

    2017-04-01

    Plenoptic imaging has been used in the past decade mainly for 3D reconstruction or digital refocusing. It was also shown that this technology has potential for correcting monochromatic aberrations in a standard optical system. In this paper, we present an algorithm for reconstructing images using a projection technique while correcting defects present in it that can apply to chromatic aberrations and wide-angle optical systems. We show that the impact of noise on the reconstruction procedure is minimal. Trade-offs between the sampling of the optical system needed for characterization and image quality are presented. Examples are shown for aberrations in a classic optical system and for chromatic aberrations. The technique is also applied to a wide-angle full field of view of 140° (FFOV 140°) optical system. This technique could be used in order to further simplify or minimize optical systems.

  10. RESIDENT IMPLEMENTATION OF THE 2007 ACC/AHA GUIDELINES ON PREOPERATIVE CARDIAC EVALUATION IN NON-CARDIAC SURGERY PATIENTS: IS CLINICAL EXPERIENCE ENOUGH?

    PubMed

    Amhaz, Hassan H; Kuo, Ruth; Chidiac, Elie J; Pallekonda, Vinay; Fuleihan, Samir F; McKelvey, George; Kaddoum, Romeo N

    2015-06-01

    Preoperative evaluation of surgical patients is important, as perioperative complications are associated with increased mortality. Specialties including anesthesiology, internal medicine, cardiology, and surgery are involved in the evaluation and management of these patients. This institutional study investigated the residents' knowledge of the 2007 American College of Cardiology/American Heart Association (ACC/AHA) guidelines on perioperative evaluation of patients undergoing non-cardiac surgery. This pilot study used a web-based survey questionnaire to assess resident's knowledge of the 2007 ACC/AHA guidelines through individual steps and corresponding branch point(s) in twelve clinical scenarios. Additionally, residents were asked if they were aware of, or if they had received lectures on ACC/AHA guidelines. Staff anesthesiologists with training in cardiac and intensive care medicine validated the scenarios. A total of 104 resident participants were surveyed including 35 anesthesiology residents, 41 internal medicine residents, 20 surgery residents, and 8 cardiology fellows. Awareness of the 2007 ACC/AHA guidelines by specialty was: anesthesiology (85%), internal medicine (97.6%), cardiology (100%), and surgery (70%). Only 54.3% of anesthesiology, 31.7% of internal medicine, 100% of cardiology, and 10% of surgery residents stated they received lectures. The overall mean score achieved on the eleven scenarios was 50.4% for anesthesiology, 47.0% for internal medicine, 55.7% for cardiology, and 42.3% for surgery. Although the majority of residents were aware of the 2007 ACC/AHA guidelines, fewer received lectures and regardless of specialty, implementation of these guidelines was poor. There exists significant room for improvement in the understanding of preoperative assessment of non-cardiac surgery patients.

  11. Chromatic multifocal pupillometer for objective perimetry in patients with macular degeneration (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Rotenstreich, Ygal; Ben-Ner, Daniel; Mahajna, Mohamad; Chibel, Ron; Sher, Ifat

    2016-03-01

    Purpose: To objectively assess visual field (VF) defects and retinal cell function in healthy subjects and patients with macular degeneration using a chromatic multifocal pupillometer. Methods: A multifocal chromatic pupillometer (MCP) was used to record pupillary responses (PR) of 17 healthy subjects and 5 Best Vitelliform macular dystrophy patients. Blue and red light stimuli (peak 485nm and 620nm, respectively) were presented at light intensities of 400 and 1000 cd/m2, respectively at 76 different points in a 16.2 degree VF. The PR of patients were compared with their findings on Humphrey's 24-2 perimetry, optical coherence tomography and the PR obtained from healthy subjects. Results: Patients demonstrated reduced percentage of pupillary contraction and slower maximal contraction velocity, more than two standard errors (SE) away from the mean of healthy subjects in response to red light in majority of VF locations. In response to blue light, the percentage of pupillary contraction was lower (by over two SE) compared with normal controls only in central locations. The latency of maximal contraction velocity was shorter in patients compared with healthy subjects in response to both colors. Conclusions: This study demonstrated the advantage of using MCP-based objective VF to assess central scotoma in macular degeneration. Our finding also suggests that chromatic perimetry may differentiate between PR mediated by cones and rods, and can specifically detect defects in macular cones. Different parameters of PR such as latency of maximal contraction velocity may shed light on the pathophysiology of different blinding diseases.

  12. Chromatic and achromatic monocular deprivation produce separable changes of eye dominance in adults.

    PubMed

    Zhou, Jiawei; Reynaud, Alexandre; Kim, Yeon Jin; Mullen, Kathy T; Hess, Robert F

    2017-11-29

    Temporarily depriving one eye of its input, in whole or in part, results in a transient shift in eye dominance in human adults, with the patched eye becoming stronger and the unpatched eye weaker. However, little is known about the role of colour contrast in these behavioural changes. Here, we first show that the changes in eye dominance and contrast sensitivity induced by monocular eye patching affect colour and achromatic contrast sensitivity equally. We next use dichoptic movies, customized and filtered to stimulate the two eyes differentially. We show that a strong imbalance in achromatic contrast between the eyes, with no colour content, also produces similar, unselective shifts in eye dominance for both colour and achromatic contrast sensitivity. Interestingly, if this achromatic imbalance is paired with similar colour contrast in both eyes, the shift in eye dominance is selective, affecting achromatic but not chromatic contrast sensitivity and revealing a dissociation in eye dominance for colour and achromatic image content. On the other hand, a strong imbalance in chromatic contrast between the eyes, with no achromatic content, produces small, unselective changes in eye dominance, but if paired with similar achromatic contrast in both eyes, no changes occur. We conclude that perceptual changes in eye dominance are strongly driven by interocular imbalances in achromatic contrast, with colour contrast having a significant counter balancing effect. In the short term, eyes can have different dominances for achromatic and chromatic contrast, suggesting separate pathways at the site of these neuroplastic changes. © 2017 The Author(s).

  13. SIMULTANEOUS DTERMINATION OF CHROMATE AND AROMATIC HYDROCARBONS IN ENVIRONMENTAL SAMPLES BY CAPILLARY ELECTROPHORESIS

    EPA Science Inventory

    An analytical method was developed to determine simultaneously, the inorganic anion CrO2-4, and organic aromatic compounds including benzoate, 2-Cl-benzoate, phenol, m-cresol and o-/p-cresol by capillary electrophoresis (CE). Chromate and the aromatics were separated in a relativ...

  14. Non-Chromate/No-VOC Coating System for DoD Applications

    DTIC Science & Technology

    2009-03-31

    chromium species, at which point the corrosion protection capabilities suffer. Cr6+ is used everywhere that self - healing corrosion protection is...surface region in which the Cr6+ remains, forming a self - healing chemistry that re-protects if scratched. Thin (Class 3) chromate conversion layers are...olation polymer control color, thickness, and the self - healing property of the film [7]. TCP does not contain any free trivalent chromium and is free of

  15. Evaluation of layered zinc hydroxide nitrate and zinc/nickel double hydroxide salts in the removal of chromate ions from solutions

    NASA Astrophysics Data System (ADS)

    de Oliveira, Henrique Bortolaz; Wypych, Fernando

    2016-11-01

    Layered zinc hydroxide nitrate (ZnHN) and Zn/Ni layered double hydroxide salts were synthesized and used to remove chromate ions from solutions at pH 8.0. The materials were characterized by many instrumental techniques before and after chromate ion removal. ZnHN decomposed after contact with the chromate solution, whereas the layered structure of Zn/Ni hydroxide nitrate (Zn/NiHN) and Zn/Ni hydroxide acetate (Zn/NiHA) remained their layers intact after the topotactic anionic exchange reaction, only changing the basal distances. ZnHN, Zn/NiHN, and Zn/NiHA removed 210.1, 144.8, and 170.1 mg of CrO42-/g of material, respectively. Although the removal values obtained for Zn/NiHN and Zn/NiHA were smaller than the values predicted for the ideal formulas of the solids (194.3 and 192.4 mg of CrO42-/g of material, respectively), the measured capacities were higher than the values achieved with many materials reported in the literature. Kinetic experiments showed the removal reaction was fast. To facilitate the solid/liquid separation process after chromium removal, Zn/Ni layered double hydroxide salts with magnetic supports were also synthesized, and their ability to remove chromate was evaluated.

  16. Chromate and amine contact allergies in workers manufacturing precast concrete elements.

    PubMed

    Mowitz, Martin; Zimerson, Erik; Hauksson, Inese; Pontén, Ann

    2016-12-01

    Five workers from a plant manufacturing concrete wall panels and beams were referred to our department because of suspected occupational dermatitis. When patch tested, 3 workers reacted to potassium dichromate. Four workers reacted to ethylenediamine dihydrochloride, without any obvious exposure. Owing to the high proportion of workers with recent-onset skin disease, an investigation of all workers at the plant was initiated. To investigate the prevalence of occupational dermatitis and contact allergy in the workers at the plant. All 24 workers at the plant underwent a clinical investigation and were patch tested. Four cases of allergic occupational contact dermatitis and 3 cases of irritant occupational contact dermatitis were diagnosed. Contact allergy to potassium dichromate was found in 4 workers. All 4 also reacted to ethylenediamine dihydrochloride and/or amines that were present as additives in the cement. Chromate contact allergy can still be found in concrete workers, despite the legislation regulating the amount of hexavalent chromium (chromate) in cement. Occupational contact allergy to amines can be found in workers exposed to cement and concrete, so amines should be tested in these workers. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Homologous Recombination Repair Protects Against Particulate Chromate-induced Chromosome Instability in Chinese Hamster Cells

    PubMed Central

    Stackpole, Megan M.; Wise, Sandra S.; Duzevik, Eliza Grlickova; Munroe, Ray C.; Thompson, W. Douglas; Thacker, John; Thompson, Larry H.; Hinz, John M.; Wise, John Pierce

    2008-01-01

    Particulate hexavalent chromium [Cr(VI)] compounds are well-established human carcinogens. Cr(VI)-induced tumors are characterized by chromosomal instability (CIN); however, the mechanisms of this effect are unknown. We investigated the hypothesis that homologous recombination (HR) repair of DNA double strand breaks protect cells from Cr(VI)-induced CIN by focusing on the XRCC3 and RAD51C genes, which play an important role in cellular resistance to DNA double strand breaks. We used Chinese hamster cells defective in each HR gene (irs3 for RAD51C and irs1SF for XRCC3) and compared with their wildtype parental and cDNA-complemented controls. We found that the intracellular Cr ion levels varied among the cell lines after particulate chromate treatment. Importantly, accounting for differences in Cr ion levels, we discovered that XRCC3 and RAD51C cells treated with lead chromate had increased cytotoxicity and chromosomal aberrations, relative to wild-type and cDNA-complimented cells. We also observed the emergence of high levels of chromatid exchanges in the two mutant cell lines. For example, 1 ug/cm2 lead chromate induced 20 and 32 exchanges in XRCC3- and RAD51C-deficient cells, respectively, whereas no exchanges were detected in the wildtype and cDNA-complemented cells. These observations suggest that HR protects cells from Cr(VI)-induced CIN, consistent with the ability of particulate Cr(VI) to induce double strand breaks. PMID:17662313

  18. Molybdenum-copper and tungsten-copper alloys and method of making

    DOEpatents

    Schmidt, Frederick A.; Verhoeven, John D.; Gibson, Edwin D.

    1989-05-23

    Molybdenum-copper and tungsten-copper alloys are prepared by a consumable electrode method in which the electrode consists of a copper matrix with embedded strips of refractory molybdenum or tungsten. The electrode is progressively melted at its lower end with a superatmospheric inert gas pressure maintained around the liquifying electrode. The inert gas pressure is sufficiently above the vapor pressure of copper at the liquidus temperature of the alloy being formed to suppress boiling of liquid copper.

  19. Molybdenum-copper and tungsten-copper alloys and method of making

    DOEpatents

    Schmidt, F.A.; Verhoeven, J.D.; Gibson, E.D.

    1989-05-23

    Molybdenum-copper and tungsten-copper alloys are prepared by a consumable electrode method in which the electrode consists of a copper matrix with embedded strips of refractory molybdenum or tungsten. The electrode is progressively melted at its lower end with a superatmospheric inert gas pressure maintained around the liquefying electrode. The inert gas pressure is sufficiently above the vapor pressure of copper at the liquidus temperature of the alloy being formed to suppress boiling of liquid copper. 6 figs.

  20. Variations of the Antarctic Circumpolar Current (ACC) in the Kerguelen Sector during the Last Deglaciation : sedimentological and geochemical evidences

    NASA Astrophysics Data System (ADS)

    Bout-Roumazeilles, V.; Beny, F.; Mazaud, A.; Michel, E.; Crosta, X.; Davies, G. R.; Bory, A. J. M.

    2017-12-01

    High-resolution sedimentological and geochemical records were obtained from two sediment cores recovered by the French R/V Marion Dufresne during the INDIEN-SUD-ACC cruises near the sub-Antarctic Kerguelen Islands (49°S). This area is ideal to record past oceanic and atmospheric changes in the Southern Ocean because they are currently located in the northern branch of the Antarctic Circumpolar Current and under the direct influence of Southern Hemisphere Westerly wind belt. This study focuses on the last termination, with specific emphasis on the impact of severe climatic events (Heinrich Stadial 1, Antarctic Cold Reversal, Younger Dryas) onto the ocean-atmospheric exchange. Results indicates that most of the sediment is derived from the Kerguelen Plateau, characterized by high smectite content. Periodically, a minor contribution of Antarctica is noticeable. In particular, illite variations suggest fast and short northward incursions of Antarctic Bottom Water, probably formed in the Prydz Bay during the last glaciation. Grainsize repartition combined to magnetic parameters show a southward migration of the ACC and the fronts associated from the beginning of the deglaciation, which is consistent with Southern Hemisphere climate variations. On the opposite, it highlights an asynchronous decrease of the ACC strength, with a large drop during the Antarctic Cold Reversal when atmospheric CO2 increase was slowed down. Thus, at least in the studied area, the ACC strength and the Antarctic Climate were not synchronous during the last deglaciation.

  1. A type III ACC synthase, ACS7, is involved in root gravitropism in Arabidopsis thaliana

    PubMed Central

    Chang, Ing-Feng

    2013-01-01

    Ethylene is an important plant hormone that regulates developmental processes in plants. The ethylene biosynthesis pathway is a highly regulated process at both the transcriptional and post-translational level. The transcriptional regulation of these ethylene biosynthesis genes is well known. However, post-translational modifications of the key ethylene biosynthesis enzyme 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS) are little understood. In vitro kinase assays were conducted on the type III ACS, AtACS7, fusion protein and peptides to determine whether the AtACS7 protein can be phosphorylated by calcium-dependent protein kinase (CDPK). AtACS7 was phosphorylated at Ser216, Thr296, and Ser299 by AtCDPK16 in vitro. To investigate further the function of the ACS7 gene in Arabidopsis, an acs7-1 loss-of-function mutant was isolated. The acs7-1 mutant exhibited less sensitivity to the inhibition of root gravitropism by treatment with the calcium chelator ethylene glycol tetraacetic acid (EGTA). Seedlings were treated with gradient concentrations of ACC. The results showed that a certain concentration of ethylene enhanced the gravity response. Moreover, the acs7-1 mutant was less sensitive to inhibition of the gravity response by treatment with the auxin polar transport inhibitor 1-naphthylphthalamic acid, but exogenous ACC application recovered root gravitropism. Altogether, the results indicate that AtACS7 is involved in root gravitropism in a calcium-dependent manner in Arabidopsis. PMID:23943848

  2. A type III ACC synthase, ACS7, is involved in root gravitropism in Arabidopsis thaliana.

    PubMed

    Huang, Shih-Jhe; Chang, Chia-Lun; Wang, Po-Hsun; Tsai, Min-Chieh; Hsu, Pang-Hung; Chang, Ing-Feng

    2013-11-01

    Ethylene is an important plant hormone that regulates developmental processes in plants. The ethylene biosynthesis pathway is a highly regulated process at both the transcriptional and post-translational level. The transcriptional regulation of these ethylene biosynthesis genes is well known. However, post-translational modifications of the key ethylene biosynthesis enzyme 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS) are little understood. In vitro kinase assays were conducted on the type III ACS, AtACS7, fusion protein and peptides to determine whether the AtACS7 protein can be phosphorylated by calcium-dependent protein kinase (CDPK). AtACS7 was phosphorylated at Ser216, Thr296, and Ser299 by AtCDPK16 in vitro. To investigate further the function of the ACS7 gene in Arabidopsis, an acs7-1 loss-of-function mutant was isolated. The acs7-1 mutant exhibited less sensitivity to the inhibition of root gravitropism by treatment with the calcium chelator ethylene glycol tetraacetic acid (EGTA). Seedlings were treated with gradient concentrations of ACC. The results showed that a certain concentration of ethylene enhanced the gravity response. Moreover, the acs7-1 mutant was less sensitive to inhibition of the gravity response by treatment with the auxin polar transport inhibitor 1-naphthylphthalamic acid, but exogenous ACC application recovered root gravitropism. Altogether, the results indicate that AtACS7 is involved in root gravitropism in a calcium-dependent manner in Arabidopsis.

  3. A durability test of wood posts in Hawaii...third progress report

    Treesearch

    Roger G. Skolmen

    1971-01-01

    Round posts of 10 Hawaii-grown wood species were treated with copper chromate-copper arsenate by the double-diffusion process. These and untreated posts were exposed for 10 years. Except with two coniferous species, the treatment did not lengthen service life enough to be judged worthwhile.

  4. Fifty-Year Durability Evaluation of Posts Treated with Industrial Wood Preservatives

    Treesearch

    Stan T. Lebow; Patricia Lebow; Bessie Woodward; Grant T. Kirker; Rachel Arango

    2015-01-01

    Long-term durability data are needed to improve service life estimates for treated wood products used as critical structural supports in industrial applications. This article reports the durability of longleaf pine (Pinus palustris) posts pressure treated with ammoniacal copper arsenate (ACA), chromated copper arsenate (CCA), creosote, or...

  5. Dispersion strengthened copper

    DOEpatents

    Sheinberg, H.; Meek, T.T.; Blake, R.D.

    1990-01-09

    A composition of matter is described which is comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide. A method for making this composition of matter is also described. This invention relates to the art of powder metallurgy and, more particularly, it relates to dispersion strengthened metals.

  6. Determination of nanomolar chromate in drinking water with solid phase extraction and a portable spectrophotometer.

    PubMed

    Ma, Jian; Yang, Bo; Byrne, Robert H

    2012-06-15

    Determination of chromate at low concentration levels in drinking water is an important analytical objective for both human health and environmental science. Here we report the use of solid phase extraction (SPE) in combination with a custom-made portable light-emitting diode (LED) spectrophotometer to achieve detection of chromate in the field at nanomolar levels. The measurement chemistry is based on a highly selective reaction between 1,5-diphenylcarbazide (DPC) and chromate under acidic conditions. The Cr-DPC complex formed in the reaction can be extracted on a commercial C18 SPE cartridge. Concentrated Cr-DPC is subsequently eluted with methanol and detected by spectrophotometry. Optimization of analytical conditions involved investigation of reagent compositions and concentrations, eluent type, flow rate (sample loading), sample volume, and stability of the SPE cartridge. Under optimized conditions, detection limits are on the order of 3 nM. Only 50 mL of sample is required for an analysis, and total analysis time is around 10 min. The targeted analytical range of 0-500 nM can be easily extended by changing the sample volume. Compared to previous SPE-based spectrophotometric methods, this analytical procedure offers the benefits of improved sensitivity, reduced sample consumption, shorter analysis time, greater operational convenience, and lower cost. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Novel technique: a pupillometer-based objective chromatic perimetry

    NASA Astrophysics Data System (ADS)

    Rotenstreich, Ygal; Skaat, Alon; Sher, Ifat; Kolker, Andru; Rosenfeld, Elkana; Melamed, Shlomo; Belkin, Michael

    2014-02-01

    Evaluation of visual field (VF) is important for clinical diagnosis and patient monitoring. The current VF methods are subjective and require patient cooperation. Here we developed a novel objective perimetry technique based on the pupil response (PR) to multifocal chromatic stimuli in normal subjects and in patients with glaucoma and retinitis pigmentosa (RP). A computerized infrared video pupillometer was used to record PR to short- and long-wavelength stimuli (peak 485 nm and 620 nm, respectively) at light intensities of 15-100 cd-s/m2 at thirteen different points of the VF. The RP study included 30 eyes of 16 patients and 20 eyes of 12 healthy participants. The glaucoma study included 22 eyes of 11 patients and 38 eyes of 19 healthy participants. Significantly reduced PR was observed in RP patients in response to short-wavelength stimuli at 40 cd-s/m2 in nearly all perimetric locations (P <0.05). By contrast, RP patients demonstrated nearly normal PR to long-wavelength in majority of perimetric locations. The glaucoma group showed significantly reduced PR to long- and short-wavelength stimuli at high intensity in all perimetric locations (P <0.05). The PR of glaucoma patients was significantly lower than normal in response to short-wavelength stimuli at low intensity mostly in central and 20° locations (p<0.05). This study demonstrates the feasibility of using pupillometer-based chromatic perimetry for objectively assessing VF defects and retinal function and optic nerve damage in patients with retinal dystrophies and glaucoma. Furthermore, this method may be used to distinguish between the damaged cells underlying the VF defect.

  8. Estimation of chromatic errors from broadband images for high contrast imaging: sensitivity analysis

    NASA Astrophysics Data System (ADS)

    Sirbu, Dan; Belikov, Ruslan

    2016-01-01

    Many concepts have been proposed to enable direct imaging of planets around nearby stars, and which would enable spectroscopic observations of their atmospheric observations and the potential discovery of biomarkers. The main technical challenge associated with direct imaging of exoplanets is to effectively control both the diffraction and scattered light from the star so that the dim planetary companion can be seen. Usage of an internal coronagraph with an adaptive optical system for wavefront correction is one of the most mature methods and is being developed as an instrument addition to the WFIRST-AFTA space mission. In addition, such instruments as GPI and SPHERE are already being used on the ground and are yielding spectra of giant planets. For the deformable mirror (DM) to recover a dark hole region with sufficiently high contrast in the image plane, mid-spatial frequency wavefront errors must be estimated. To date, most broadband lab demonstrations use narrowband filters to obtain an estimate of the the chromaticity of the wavefront error and this can result in usage of a large percentage of the total integration time. Previously, we have proposed a method to estimate the chromaticity of wavefront errors using only broadband images; we have demonstrated that under idealized conditions wavefront errors can be estimated from images composed of discrete wavelengths. This is achieved by using DM probes with sufficient spatially-localized chromatic diversity. Here we report on the results of a study of the performance of this method with respect to realistic broadband images including noise. Additionally, we study optimal probe patterns that enable reduction of the number of probes used and compare the integration time with narrowband and IFS estimation methods.

  9. Potentiation of motor sub-networks for motor control but not working memory: Interaction of dACC and SMA revealed by resting-state directed functional connectivity

    PubMed Central

    Diwadkar, Vaibhav A.; Asemi, Avisa; Burgess, Ashley; Chowdury, Asadur; Bressler, Steven L.

    2017-01-01

    The dorsal Anterior Cingulate Cortex (dACC) and the Supplementary Motor Area (SMA) are known to interact during motor coordination behavior. We previously discovered that the directional influences underlying this interaction in a visuo-motor coordination task are asymmetric, with the dACC→SMA influence being significantly greater than that in the reverse direction. To assess the specificity of this effect, here we undertook an analysis of the interaction between dACC and SMA in two distinct contexts. In addition to the motor coordination task, we also assessed these effects during a (n-back) working memory task. We applied directed functional connectivity analysis to these two task paradigms, and also to the rest condition of each paradigm, in which rest blocks were interspersed with task blocks. We report here that the previously known asymmetric interaction between dACC and SMA, with dACC→SMA dominating, was significantly larger in the motor coordination task than the memory task. Moreover the asymmetry between dACC and SMA was reversed during the rest condition of the motor coordination task, but not of the working memory task. In sum, the dACC→SMA influence was significantly greater in the motor task than the memory task condition, and the SMA→dACC influence was significantly greater in the motor rest than the memory rest condition. We interpret these results as suggesting that the potentiation of motor sub-networks during the motor rest condition supports the motor control of SMA by dACC during the active motor task condition. PMID:28278267

  10. 21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Potassium sodium copper chlorophyllin... § 73.2125 Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). (a) Identity and specifications. The color additive potassium sodium copper chlorophyllin shall conform in identity and...

  11. 21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Potassium sodium copper chlorophyllin... § 73.2125 Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). (a) Identity and specifications. The color additive potassium sodium copper chlorophyllin shall conform in identity and...

  12. 21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Potassium sodium copper chlorophyllin... § 73.2125 Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). (a) Identity and specifications. The color additive potassium sodium copper chlorophyllin shall conform in identity and...

  13. What's next for dyslipidemia management? The 2013 ACC/AHA Guidelines, the NLA recommendations, and beyond.

    PubMed

    Waite, Laura H; Phan, Yvonne L; Spinler, Sarah A

    2016-01-01

    To compare and contrast the 2013 American College of Cardiology (ACC)/American Heart Association (AHA) Guidelines and the 2014/2015 National Lipid Association (NLA) Recommendations for Management of Dyslipidemia in the context of evolving evidence. Guidelines from the National Cholesterol Education Program (NCEP), ACC/AHA, and NLA; recent clinical trials involving non-statin therapies. Not applicable. At the authors' discretion, preference was given to references focusing on guidelines and recent clinical trials involving dyslipidemia management. In late 2013, the ACC/AHA released guidelines on the treatment of blood cholesterol to reduce risk for atherosclerotic cardiovascular disease (ASCVD) in adults. Reflecting contemporary evidence-based literature, low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C) numeric treatment goals were eliminated, and a new method of risk assessment (the Pooled Cohort Equations) was recommended. The guidelines emphasized lipid lowering in 4 patient populations proven to benefit from statin therapy, recommending moderate to high-intensity statin dosing, with no additional drug therapies and limited ongoing monitoring. Clinical controversies ignited by these guidelines led to the publication of recommendations by the NLA in 2014 and 2015. Part 1 of the NLA recommendations incorporated parts of both the ATP III guidelines and the 2013 ACC/AHA guidelines along with updated original recommendations. These recommendations provided numeric LDL-C, non-HDL-C, and apolipoprotein B treatment goals and potential additional ASCVD risk factors, with stepwise risk assessment based on traditional cardiac risk factors and multiple assessment tools. In addition to statins, the 2014 NLA recommendations highlighted the benefit of additional or alternative lipid-lowering therapies. Part 2 of the NLA recommendations expanded the guidance for treatment of special populations and prioritized ezetimibe as a

  14. 21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Potassium sodium copper chloropyhllin....1125 Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). (a) Identity. (1) The color additive potassium sodium copper chlorophyllin is a green to black powder obtained from chlorophyll by...

  15. Psychophysical Evaluation of Achromatic and Chromatic Vision of Workers Chronically Exposed to Organic Solvents

    PubMed Central

    Lacerda, Eliza Maria da Costa Brito; Lima, Monica Gomes; Rodrigues, Anderson Raiol; Teixeira, Cláudio Eduardo Correa; de Lima, Lauro José Barata; Ventura, Dora Fix; Silveira, Luiz Carlos de Lima

    2012-01-01

    The purpose of this paper was to evaluate achromatic and chromatic vision of workers chronically exposed to organic solvents through psychophysical methods. Thirty-one gas station workers (31.5 ± 8.4 years old) were evaluated. Psychophysical tests were achromatic tests (Snellen chart, spatial and temporal contrast sensitivity, and visual perimetry) and chromatic tests (Ishihara's test, color discrimination ellipses, and Farnsworth-Munsell 100 hue test—FM100). Spatial contrast sensitivities of exposed workers were lower than the control at spatial frequencies of 20 and 30 cpd whilst the temporal contrast sensitivity was preserved. Visual field losses were found in 10–30 degrees of eccentricity in the solvent exposed workers. The exposed workers group had higher error values of FM100 and wider color discrimination ellipses area compared to the controls. Workers occupationally exposed to organic solvents had abnormal visual functions, mainly color vision losses and visual field constriction. PMID:22220188

  16. Migration of copper and some other metals from copper tableware

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ishiwata, H.; Inoue, T.; Yoshihira, K.

    Intake of heavy metals is an important problem in human health. Certain heavy metals are avoided with regard to their use for utensils or tableware coming into contact with food, although copper is widely used in food processing factories or at home. The use of copper products for the processing, cooking or serving of foods and beverages is considered to be a cause of a copper contamination. Although copper is essential element, its excess ingestion is undesirable. In this study, the migration of copper from tin-plated or non-plated copperware under several experimental conditions was investigated using food-simulating solvents.

  17. Copper toxicity in the crab, Scylla serrata, copper levels in tissues and regulation after exposure to a copper-rich medium

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Arumugam, M.; Ravindranath, M.H.

    1987-10-01

    In the decapod crustaceans copper is distributed in various tissues. In these animals the tissue copper generally exists in four forms; ionic, bound to proteins, lipids and membrane. In the estuarine crab Scylla serrata, the haemolymph copper exists only in association with proteins, whereas in the hepatopancreas it exists in all the four forms and in gills it exists in all the forms except in combination with lipids. Although food is the major source of copper in decapod crustaceans evidence indicate that copper may be directly obtained from the environment. It was postulated earlier that in Scylla serrata the haemolymphmore » and hepatopancreas may be involved in copper regulation. In the present work the authors have studied the nature and levels of copper in different tissues after exposing the crabs to copper-rich medium. The results indicate the relative importance of various tissues in accumulation an the possible mechanisms of regulation of the environmental copper. Besides, as a pre-requisite for studies of this kind, the toxic levels for different forms of copper were estimated since the form of toxicant is known to influence the toxicity to the decapod crustaceans.« less

  18. [Preparation and chromaticity properties of colored dental 3Y-TZP ceramics].

    PubMed

    Yi, Yuan-fu; Wang, Chen; Tian, Jie-mo; Liu, Hong-chen; Wen, Ning

    2008-10-01

    To obtain and investigate the chromaticity properties of colored dental 3Y-TZP ceramics with different colorant combinations. Colorant combinations were mixed with TZ-3Y-S powder, then the mixtures were compacted at 200 MPa using cold isostatic pressure, densely sintered at 1500 degrees C for 2 h forming 5 graded colored dental zirconia ceramics. Specimen were sectioned into 10 mm x 10 mm x 0.5 mm and 10 mm x l0 mmx 1 mm slices from the sintered blocks. Color measurement was performed under black background using spectrophotometer. The chromaticity properties were compared with that of the VITA In-Ceram YZ shade guide. Five colored dental zirconia ceramics were obtained. The lightness decreased gradually, and the chroma value increased gradually. The color differences of the two thickness specimens were little. The parameters of the color space were L*: 67.76-77.78; a*: -2.19-3.80; b*: 12.13-25.01, which was similar with that of the VITA In-Ceram YZ shade guide, while the lowest value of lightness was relatively higher than that of the VITA In-Ceram YZ shade guide. Colored 3Y-TZP dental ceramics are suitable for clinical use. There is a need to develop more darkness shaded zirconia dental ceramics.

  19. Improved Electroformed Structural Copper and Copper Alloys

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Hudson, W.; Babcock, B.; Edwards, R.

    1998-01-01

    Electroforming offers a superior means for fabricating internally cooled heat exchangers and structures subjected to thermal environments. Copper is deposited from many such applications because of the good thermal conductivity. It suffers from mediocre yield strength as a structural material and loses mechanical strength at intermediate temperatures. Mechanical properties similar to those of electroformed nickel are desired. Phase 1 examined innovative means to improve deposited copper structural performance. Yield strengths as high as 483 MPa (70 ksi) were obtained with useful ductility while retaining a high level of purity essential to good thermal conductivity. Phase 2 represents a program to explore new additive combinations in copper electrolytes to produce a more fine, equiaxed grain which can be thermally stabilized by other techniques such as alloying in modest degrees and dispersion strengthening. Evaluation of new technology - such as the codeposition of fullerness (diamond-like) particles were made to enhance thermal conductivity in low alloys. A test fire quality tube-bundle engine was fabricated using these copper property improvement concepts to show the superiority of the new coppers and fabrications methods over competitive technologies such as brazing and plasma deposition.

  20. Luminance and chromatic signals interact differently with melanopsin activation to control the pupil light response.

    PubMed

    Barrionuevo, Pablo A; Cao, Dingcai

    2016-09-01

    Intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin. These cells receive afferent inputs from rods and cones, which provide inputs to the postreceptoral visual pathways. It is unknown, however, how melanopsin activation is integrated with postreceptoral signals to control the pupillary light reflex. This study reports human flicker pupillary responses measured using stimuli generated with a five-primary photostimulator that selectively modulated melanopsin, rod, S-, M-, and L-cone excitations in isolation, or in combination to produce postreceptoral signals. We first analyzed the light adaptation behavior of melanopsin activation and rod and cones signals. Second, we determined how melanopsin is integrated with postreceptoral signals by testing with cone luminance, chromatic blue-yellow, and chromatic red-green stimuli that were processed by magnocellular (MC), koniocellular (KC), and parvocellular (PC) pathways, respectively. A combined rod and melanopsin response was also measured. The relative phase of the postreceptoral signals was varied with respect to the melanopsin phase. The results showed that light adaptation behavior for all conditions was weaker than typical Weber adaptation. Melanopsin activation combined linearly with luminance, S-cone, and rod inputs, suggesting the locus of integration with MC and KC signals was retinal. The melanopsin contribution to phasic pupil responses was lower than luminance contributions, but much higher than S-cone contributions. Chromatic red-green modulation interacted with melanopsin activation nonlinearly as described by a "winner-takes-all" process, suggesting the integration with PC signals might be mediated by a postretinal site.