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Sample records for agro-biofuel production negates

  1. N2O release from agro-biofuel production negates global warming reduction by replacing fossil fuels

    NASA Astrophysics Data System (ADS)

    Crutzen, P. J.; Mosier, A. R.; Smith, K. A.; Winiwarter, W.

    2008-01-01

    The relationship, on a global basis, between the amount of N fixed by chemical, biological or atmospheric processes entering the terrestrial biosphere, and the total emission of nitrous oxide (N2O), has been re-examined, using known global atmospheric removal rates and concentration growth of N2O as a proxy for overall emissions. For both the pre-industrial period and in recent times, after taking into account the large-scale changes in synthetic N fertiliser production, we find an overall conversion factor of 3-5% from newly fixed N to N2O-N. We assume the same factor to be valid for biofuel production systems. It is covered only in part by the default conversion factor for "direct" emissions from agricultural crop lands (1%) estimated by IPCC (2006), and the default factors for the "indirect" emissions (following volatilization/deposition and leaching/runoff of N: 0.35-0.45%) cited therein. However, as we show in the paper, when additional emissions included in the IPCC methodology, e.g. those from livestock production, are included, the total may not be inconsistent with that given by our "top-down" method. When the extra N2O emission from biofuel production is calculated in "CO2-equivalent" global warming terms, and compared with the quasi-cooling effect of "saving" emissions of fossil fuel derived CO2, the outcome is that the production of commonly used biofuels, such as biodiesel from rapeseed and bioethanol from corn (maize), depending on N fertilizer uptake efficiency by the plants, can contribute as much or more to global warming by N2O emissions than cooling by fossil fuel savings. Crops with less N demand, such as grasses and woody coppice species, have more favourable climate impacts. This analysis only considers the conversion of biomass to biofuel. It does not take into account the use of fossil fuel on the farms and for fertilizer and pesticide production, but it also neglects the production of useful co-products. Both factors partially compensate

  2. Negative hydrogen ion production mechanisms

    SciTech Connect

    Bacal, M.; Wada, M.

    2015-06-15

    Negative hydrogen/deuterium ions can be formed by processes occurring in the plasma volume and on surfaces facing the plasma. The principal mechanisms leading to the formation of these negative ions are dissociative electron attachment to ro-vibrationally excited hydrogen/deuterium molecules when the reaction takes place in the plasma volume, and the direct electron transfer from the low work function metal surface to the hydrogen/deuterium atoms when formation occurs on the surface. The existing theoretical models and reported experimental results on these two mechanisms are summarized. Performance of the negative hydrogen/deuterium ion sources that emerged from studies of these mechanisms is reviewed. Contemporary negative ion sources do not have negative ion production electrodes of original surface type sources but are operated with caesium with their structures nearly identical to volume production type sources. Reasons for enhanced negative ion current due to caesium addition to these sources are discussed.

  3. Photosynthesis and negative entropy production.

    PubMed

    Jennings, Robert C; Engelmann, Enrico; Garlaschi, Flavio; Casazza, Anna Paola; Zucchelli, Giuseppe

    2005-09-30

    The widely held view that the maximum efficiency of a photosynthetic pigment system is given by the Carnot cycle expression (1-T/Tr) for energy transfer from a hot bath (radiation at temperature Tr) to a cold bath (pigment system at temperature T) is critically examined and demonstrated to be inaccurate when the entropy changes associated with the microscopic process of photon absorption and photochemistry at the level of single photosystems are considered. This is because entropy losses due to excited state generation and relaxation are extremely small (DeltaS < T/Tr) and are essentially associated with the absorption-fluorescence Stokes shift. Total entropy changes associated with primary photochemistry for single photosystems are shown to depend critically on the thermodynamic efficiency of the process. This principle is applied to the case of primary photochemistry of the isolated core of higher plant photosystem I and photosystem II, which are demonstrated to have maximal thermodynamic efficiencies of xi > 0.98 and xi > 0.92 respectively, and which, in principle, function with negative entropy production. It is demonstrated that for the case of xi > (1-T/Tr) entropy production is always negative and only becomes positive when xi < (1-T/Tr). PMID:16139784

  4. Production systems need negation as failure

    SciTech Connect

    Phan Minh Dung; Mancarella, P.

    1996-12-31

    We study action rule based systems with two forms of negation, namely classical negation and {open_quotes}negation as failure to find a course of actions{close_quotes}. We show by several examples that adding negation as failure to such systems increase their expressiveness, in the sense that real life problems can be represented in a natural and simple way. Then, we address the problem of providing a formal declarative semantics to these extended systems, by adopting an argumentation based approach, which has been shown to be a simple unifying framework for understanding the declarative semantics of various nonmonotonic formalisms. In this way, we naturally define the grounded (well-founded), stable and preferred semantics for production systems with negation as failure. Next, we characterize the class of stratified production systems, which enjoy the properties that the above mentioned semantics coincide and that negation as failure can be computed by a simple bottom-up operator.

  5. Hydrogen Plasmas for Negative Ion Production

    SciTech Connect

    Pagano, D.; Gorse, C.; Capitelli, M.

    2005-05-16

    We have improved a zero-dimensional model, built to simulate the operating conditions in the excitation ('driver') region of a multicusp ion source optimized for negative ion production of great interest in thermonuclear applications. The new approach to couple heavy particle and electron kinetics is discussed.

  6. Is Higher Education a Negative Product?

    ERIC Educational Resources Information Center

    Widrick, Stanley; Fram, Eugene

    1984-01-01

    Evidence from a Rochester, New York study of high school and college students suggests that, for major student segments, higher education can be a negative product. Students may attend college to get away from family, procrastinate from job-seeking, locate a spouse, or meet higher job and salary requirements. Marketing implications are discussed.…

  7. Comparative air, soil, and water quality impacts of common agro-ecosystems and a restored prairie and implications for agro-biofuels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cost-benefit analysis of agroecosystems requires crop productivity be supplemented by a complete accounting of the system’s environmental footprint. Between 1998 and 2006, we quantified impacts of common cropping systems on greenhouse gas and leaching losses of nutrients and soil C and N pools. Syst...

  8. The production and destruction of negative ions

    SciTech Connect

    Pegg, D.J.

    1993-01-01

    Single photon absorption-single electron detachment from few-electron atomic negative ions was studied. A crossed beam apparatus is being used to perform energy- and angle-resolved photoelectron spectroscopic measurements following photodetachment. Forward-directed electrons were collected and energy analyzed. The kinetic energies and yields of the photoelectrons were obtained by fitting the spectral peaks to Gaussian functions. Electron affinities, asymmetry parameters and cross sections are determined from these measurements. A ratio method in which the cross section for the ion of interest is measured relative to that of a reference ion was used. The study of the photodetachment of Li[sup [minus

  9. Production of negative hydrogen ions on metal grids

    SciTech Connect

    Oohara, W.; Maetani, Y.; Takeda, Takashi; Takeda, Toshiaki; Yokoyama, H.; Kawata, K.

    2015-03-15

    Negative hydrogen ions are produced on a nickel grid with positive-ion irradiation. In order to investigate the production mechanism, a copper grid without the chemisorption of hydrogen atoms and positive helium ions without negative ionization are used for comparison. Positive hydrogen ions reflected on the metal surface obtain two electrons from the surface and become negatively ionized. It is found that the production yield of negative ions by desorption ionization of chemisorbed hydrogen atoms seems to be small, and the production is a minor mechanism.

  10. Atomic wall recombination and volume negative ion production

    SciTech Connect

    Pagano, Damiano; Gorse, Claudine; Capitelli, Mario

    2006-03-15

    The development of a numerical code for the modeling of negative ion sources requires the knowledge of a lot of processes occurring both in the gas phase and at the surface. The present work concerns the effect of surface processes (in particular atomic wall recombination) on the kinetics of production/destruction of negative ions. Especially in the pressure regimes useful to produce negative hydrogen ions for thermonuclear applications, wall processes can strongly affect the negative ion production acting on the vibrational distribution of molecular hydrogen.

  11. New versions of sources for nuclear polarized negative ion production

    SciTech Connect

    Dudnikov, V.G.; Shabalin, A.L. ); Wojtsekhowski, B.B. ); Belov, A.S.; Kuzik, V.E.; Plohinsky, Y.V.; Yakushev, V.P. )

    1992-10-05

    Several variants of sources for nuclear polarized negative ion production have been proposed and tested. The simple adaptation of a high intensity polarized proton source for nuclear polarized H[sup [minus

  12. Interpretations and implications of negative binomial distributions of multiparticle productions

    NASA Astrophysics Data System (ADS)

    Arisawa, Tetsuo

    2006-11-01

    The number of particles produced in high energy experiments is approximated by a negative binomial distribution. Deriving a representation of the distribution from a stochastic equation, conditions for the process to satisfy the distribution are clarified. Based on them, it is proposed that multiparticle production consists of spontaneous and induced production. The rate of the induced production is proportional to the number of existing particles. The ratio of the two production rates remains constant during the process. The “NBD space” is also defined where the number of particles produced in its subspaces follows negative binomial distributions with different parameters.

  13. Application of anomalous diffusion in production of negative ions

    NASA Astrophysics Data System (ADS)

    Jimbo, Kouichi

    1984-11-01

    The production of negative hydrogen ions is investigated in the reflex-type negative ion sources. When anomalous diffusion in the positive column was found by Hoh and Lehnert [Phys. Fluids 3, 600 (1960)], it was pointed out that the large particle loss produced by anomalous diffusion is compensated for by the larger particle production inside the plasma. In the present experiments anomalous diffusion was artificially encouraged by changing the radial electric field inside the reflex discharge. Apparent encouragement of negative ion current by the increase of the density fluctuation amplitude is observed. Twice as much negative ion current was obtained with the artificial encouragement as without. On the other hand, the larger extracted negative ion current was observed with a lower electron temperature, which is calculated from the anomalous diffusion coefficient derived from a simple nonlinear theory. This result is consistent with Wadehra's calculated results [Appl. Phys. Lett. 35, 917 (1979)].

  14. Application of anomalous diffusion in production of negative ions

    SciTech Connect

    Jimbo, K.

    1984-11-01

    The production of negative hydrogen ions is investigated in the reflex-type negative ion sources. When anomalous diffusion in the positive column was found by Hoh and Lehnert (Phys. Fluids 3, 600 (1960)), it was pointed out that the large particle loss produced by anomalous diffusion is compensated for by the larger particle production inside the plasma. In the present experiments anomalous diffusion was artificially encouraged by changing the radial electric field inside the reflex discharge. Apparent encouragement of negative ion current by the increase of the density fluctuation amplitude is observed. Twice as much negative ion current was obtained with the artificial encouragement as without. On the other hand, the larger extracted negative ion current was observed with a lower electron temperature, which is calculated from the anomalous diffusion coefficient derived from a simple nonlinear theory. This result is consistent with Wadehra's calculated results (Appl. Phys. Lett. 35, 917 (1979)).

  15. Production of Modal and Negative Particles in Greek Aphasia

    ERIC Educational Resources Information Center

    Koukoulioti, Vasiliki

    2010-01-01

    This study aims at investigating the production of the Greek modal and negative particles by non-fluent aphasic patients. These particles belong to the highest part of the verb periphrasis, so they are likely to be impaired in non-fluent aphasia, according to some hypotheses about agrammatic language. Moreover, there is an agreement relation…

  16. [Protein a production in coagulase-negative or clumping factor (CF)-negative isolates of Staphylococcus aureus].

    PubMed

    Piechowicz, Lidia; Garbacz, Katarzyna; Wisniewska, Katarzyna; Dajnowska-Stanczewa, Agata; Galiński, Janusz

    2005-01-01

    The aim of study was to determine a production of proteinA in coagulase-negative Staphylococcus aureus (CNSA) or CF-negative S. aureus (CFNSA) strains. 59 CNSA and 18 CFNSA strains were isolated between 1997 and 2003 from different clinical specimens. The Protein A production was determined by immunoblotting method. The presence of protein A gene (spa) was investigated using the polymerase chain reaction (PCR). Two sets of phages and RFLP (Restriction Fragment Lenth Polymorphism) of coa gene method were used for typing strains. The results proved that the lack of ability of protein A production occurs more frequently in protein A-negative CFNSA strains with compare to the CNSA, which are protein A-positive for the majority of strains. Deficiencies of protein A, doesn't seem to be caused by the loss of spa gene. Protein A-negative CFNSA strains have phagotypes, RFLP and antibiotic resistant patterns which differ them from protein A-negative CNSA strains. Almost all of protein A-negative CFNSA and CNSA strains are resistant to methicillin. PMID:16494201

  17. Production of intense negative hydrogen beams with polarized nuclei by selective neutralization of cold negative ions

    DOEpatents

    Hershcovitch, A.

    1984-02-13

    A process for selectively neutralizing H/sup -/ ions in a magnetic field to produce an intense negative hydrogen ion beam with spin polarized protons. Characteristic features of the process include providing a multi-ampere beam of H/sup -/ ions that are

  18. Volume production of negative ions in the reflex-type ion source

    SciTech Connect

    Jimbo, K.

    1982-06-01

    The production of negative hydrogen ions is investigated in the reflex-type negative ion source. The extracted negative hydrogen currents of 9.7 mA (100 mA/cm/sup 2/) for H/sup -/ and of 4.1 mA(42 mA/cm/sup 2/) for D/sup -/ are obtained continuously. The impurity is less than 1%. An isotope effect of negative ion production is observed.

  19. Negative hydrogen ion production in a helicon plasma source

    SciTech Connect

    Santoso, J. Corr, C. S.; Manoharan, R.; O'Byrne, S.

    2015-09-15

    In order to develop very high energy (>1 MeV) neutral beam injection systems for applications, such as plasma heating in fusion devices, it is necessary first to develop high throughput negative ion sources. For the ITER reference source, this will be realised using caesiated inductively coupled plasma devices, containing either hydrogen or deuterium discharges, operated with high rf input powers (up to 90 kW per driver). It has been suggested that due to their high power coupling efficiency, helicon devices may be able to reduce power requirements and potentially obviate the need for caesiation due to the high plasma densities achievable. Here, we present measurements of negative ion densities in a hydrogen discharge produced by a helicon device, with externally applied DC magnetic fields ranging from 0 to 8.5 mT at 5 and 10 mTorr fill pressures. These measurements were taken in the magnetised plasma interaction experiment at the Australian National University and were performed using the probe-based laser photodetachment technique, modified for the use in the afterglow of the plasma discharge. A peak in the electron density is observed at ∼3 mT and is correlated with changes in the rf power transfer efficiency. With increasing magnetic field, an increase in the negative ion fraction from 0.04 to 0.10 and negative ion densities from 8 × 10{sup 14 }m{sup −3} to 7 × 10{sup 15 }m{sup −3} is observed. It is also shown that the negative ion densities can be increased by a factor of 8 with the application of an external DC magnetic field.

  20. Production of intense negative hydrogen beams with polarized nuclei by selective neutralization of negative ions

    DOEpatents

    Hershcovitch, Ady

    1987-01-01

    A process for selectively neutralizing H.sup.- ions in a magnetic field to produce an intense negative hydrogen ion beam with spin polarized protons. Characteristic features of the process include providing a multi-ampere beam of H.sup.- ions that are intersected by a beam of laser light. Photodetachment is effected in a uniform magnetic field that is provided around the beam of H.sup.- ions to spin polarize the H.sup.- ions and produce first and second populations or groups of ions, having their respective proton spin aligned either with the magnetic field or opposite to it. The intersecting beam of laser light is directed to selectively neutralize a majority of the ions in only one population, or given spin polarized group of H.sup.- ions, without neutralizing the ions in the other group thereby forming a population of H.sup.- ions each of which has its proton spin down, and a second group or population of H.sup.o atoms having proton spin up. Finally, the two groups of ions are separated from each other by magnetically bending the group of H.sup.- ions away from the group of neutralized ions, thereby to form an intense H.sup.- ion beam that is directed toward a predetermined objective.

  1. Production of runaway electrons by negative streamer discharges

    NASA Astrophysics Data System (ADS)

    Chanrion, O.; Neubert, T.

    2010-06-01

    In this paper we estimate the probability that cold electrons can be accelerated by an ambient electric field into the runaway regime, and discuss the implications for negative streamer formation. The study is motivated by the discovery of ms duration bursts of γ-rays from the atmosphere above thunderstorms, the so-called Terrestrial Gamma-Ray Flashes. The radiation is thought to be bremsstrahlung from energetic (MeV) electrons accelerated in a thunderstorm discharge. The observation goes against conventional wisdom that discharges in air are carried by electrons with energies below a few tens of eV. Instead the relativistic runaway electron discharge has been proposed which requires a lower threshold electric field; however, seed electrons must be born with energies in the runaway regime. In this work we study the fundamental problem of electron acceleration in a conventional discharge and the conditions on the electric field for the acceleration of electrons into the runaway regime. We use particle codes to describe the process of stochastic acceleration and introduce a novel technique that improves the statistics of the relatively few electrons that reach high energies. The calculation of probabilities for electrons to reach energies in the runaway regime shows that even with modest fields, electrons can be energized in negative streamer tips into the runaway regime, creating a beamed distribution in front of the streamer that affects its propagation. The results reported here suggest that theories of negative streamers and spark propagation should be reexamined with an improved characterization of the kinetic effects of electrons.

  2. Renormdynamics, multiparticle production, negative binomial distribution, and Riemann zeta function

    NASA Astrophysics Data System (ADS)

    Makhaldiani, N. V.

    2013-09-01

    After short introduction, we consider different aspects of the renormdynamics. Then scaling functions of the multiparticle production processes and corresponding stochastic dynamics are considered. Nonperturbative quasi-particle dynamics is considered on the base of the toy QCD- O( N)-sigma model. Last section concerns to the NBD-Riemann zeta function connection.

  3. Efficient production of transgenic cassava using negative and positive selection.

    PubMed

    Zhang, P; Potrykus, I; Puonti-Kaerlas, J

    2000-12-01

    In order to improve the efficiency of cassava (Manihot esculenta Crantz) transformation, two different selection systems were assessed, a positive one based on the use of mannose as the selective agent, and a negative one based on hygromycin resistance encoded by an intron-containing hph gene. Transgenic plants selected on mannose or hygromycin were regenerated for the first time from embryogenic suspensions cocultivated with Agrobacterium. After the initial selection using mannose and hygromycin, 82.6% and 100% of the respective developing embryogenic callus lines were transgenic. A system allowing plant regeneration from only transgenic lines was designed by combining chemical selection with histochemical GUS assays. In total, 12 morphologically normal transgenic plant lines were produced, five using mannose and seven using hygromycin. The stable integration of the transgenes into the nuclear genome was verified using PCR and Southern analysis. RT-PCR and northern analyses confirmed the transgene expression in the regenerated plants. A rooting test on mannose containing medium was developed as an alternative to GUS assays in order to eliminate escapes from the positive selection system. Our results show that transgenic cassava plants can be obtained by using either antibiotic resistance genes that are not expressed in the micro-organisms or an antibiotic-free positive selection system. PMID:11206969

  4. Development of a volume production type hydrogen negative ion source by using sheet plasma

    NASA Astrophysics Data System (ADS)

    Matsumoto, Satoki; Iijima, Takaaki; Tonegawa, Akira; Sato, Kohnosuke; Kawamura, Kazutaka

    2014-10-01

    Stationary production of negative ions are important to play an essential role in Neutral beam injection (NBI). Cesium seeded Surface-production of negative ion sources are used for NBI. However, Cesium seeded surface- production of negative ion sources are not desirable from the point of view of operating steady state ion sources. We carried out the development of negative ion sources by volume-production in hydrogen sheet plasma. Production of hydrogen negative ions through volume processes needs both high energy electron region and low energy electron region. The sheet plasma is suitable for the production of negative ions, because the electron temperature in the central region of the plasma as high as 10-15 eV, whereas in the periphery of the plasma, a low temperature of a few eV of obtained. The hydrogen negative ions density were detected using an omegatron mass analyzer, while the electron density and temperature were measured using a Langmuir probe. Negative ions current extracted from the grid are measured by Faraday-cup.

  5. Hydrogen negative-ion surface production on diamond materials in low-pressure H2 plasmas

    NASA Astrophysics Data System (ADS)

    Cartry, Gilles; Achkasov, Kostiantyn; Pardanaud, Cédric; Layet, Jean-Marc; Simonin, Alain; Gicquel, Alix; PIIM Collaboration; IRFM Collaboration; LSPM Collaboration

    2014-10-01

    Negative-ion sources producing H-current density of ~200 A/m2 are required for the heating of the fusion plasma of the international project ITER. The only up-to-date solution to reach such a high H-negative-ion current is the use of cesium (Cs). Deposition of Cs on the negative-ion source walls lowers the material work function and allows for high electron-capture efficiency by incident particles and thus, high negative ion yields. However, severe drawbacks to the use of Cs have been identified and its elimination from the fusion negative-ion sources would be highly valuable. Volume production is not efficient enough at low-pressure to reach the high current required. Therefore, we are working on alternative solutions to produce high yield of H-negative-ions on surfaces in Cs-free H2 plasmas. In this communication, we will detail the methodology employed to study negative-ion surface production. In particular we will describe how the negative-ions are extracted from the plasma, and how we can obtain information on surface production mechanisms from the measurement of the H-energy distribution functions. We will present some results obtained on diamond surfaces and show that diamond is a promising candidate as a negative-ion enhancer material in low-pressure H2 plasmas. EFDA, FR-FCM, ANR, PACA are acknowledged for their support.

  6. Effect of Art Production on Negative Mood and Anxiety for Adults in Treatment for Substance Abuse

    ERIC Educational Resources Information Center

    Laurer, Mattye; van der Vennet, Renée

    2015-01-01

    This study investigated whether art production or viewing and sorting art reproductions would be more effective in reducing negative mood and anxiety for 28 adults with substance use disorders. Participants were randomly assigned to one of two groups and completed pre- and posttest measures of negative mood and anxiety The hypothesis that art…

  7. Volume production of negative ions in the reflex type ion source

    SciTech Connect

    Jimbo, K.

    1982-01-01

    The production of negative hydrogen ions is investigated in the reflex-type negative ion source. The extracted negative hydrogen currents of 9.7 mA (100 mA/cm/sup 2/) for H/sup -/ and of 4.1 mA (42 mA/cm/sup 2/) for D/sup -/ are obtained continuously. The impurity is less then 1%. An isotope effect of negative ion production is observed. When anomalous diffusion in the positive column was found by Lehnert and Hoh (1960), it was pointed out that the large particle loss produced by anomalous diffusion is compensated by the large particle production inside the plasma, i.e., the plasma tries to maintain itself. The self-sustaining property of the plasma is applied to the reflex-type negative ion source. Anomalous diffusion was artificially encouraged by changing the radial electric field inside the reflex discharge. The apparent encouragement of negative ion diffusion by the increase of density fluctuation amplitude is observed. Twice as much negative ion current was obtained with the artificial encouragement as without. It is found from the quasilinear theory that the inwardly directed radial electric field destabilizes the plasma in the reflex-type ion source. The nonlinear theory based on Yoshikawa method (1962) is extended, and the anomalous diffusion coefficient in a weakly ionized plasma is obtained. The electrostatic sheath trap, which increases the confinement of negative ions in the reflex-type ion source, is also discussed.

  8. Volume Production of Negative Ions in the Reflex Type Ion Source.

    NASA Astrophysics Data System (ADS)

    Jimbo, Kouichi

    The production of negative hydrogen ions is investigated in the reflex-type negative ion source. The extracted negative hydrogen currents of 9.7 mA (100 mA/cm('2)) for H('-) and of 4.1 mA (42 mA/cm('2)) for D('-) are obtained continuously. The impurity is less then 1%. An isotope effect of negative ion production is observed. When anomalous diffusion in the positive column was found by Lehnert and Hoh (1960), it was pointed out that the large particle loss produced by anomalous diffusion is compensated by the large particle production inside the plasma; i.e. the plasma tries to maintain itself. "The self-sustaining property of the plasma" is applied to the reflex-type negative ion source. Anomalous diffusion was artificially encouraged by changing the radial electric field inside the reflex discharge. The apparent encouragement of negative ion diffusion by the increase of density fluctuation amplitude is observed. Twice as much negative ion current was obtained with the artificial encouragement as without. It is found from the quasilinear theory that the inwardly directed radial electric field destabilizes the plasma in the reflex-type ion source. The nonlinear theory based on Yoshikawa method (1962) is extended, and the anomalous diffusion coefficient in a weakly ionized plasma is obtained. "The electrostatic sheath trap", which increases the confinement of negative ions in the reflex-type ion source, is also discussed. It has been suggested that the dissociative attachment of electrons to excited molecules might be responsible for the high negative ion production in a hydrogen plasma: Bacal and Hamilton (1979). A recent calculation by Wadehra (1979) showed a significant enhancement of the dissociative attachment rate by the vibrational excitation of the initial molecules. The largest attachment rate was given at an electron temperature of about 1.5 eV. In our experiment, the maximum extracted negative ion current. was obtained at an electron temperature of about

  9. [Use of leukocyte-filtered, cytomegalovirus-antibody negative and irradiated cellular blood products].

    PubMed

    Solheim, B G; Albrechtsen, D H; Evensen, S A; Leivestad, T

    1990-01-10

    This paper presents both quality requirements and indications for use of leucocyte-filtered, cytomegalovirus antibody negative and irradiated cellular blood products at Rikshospitalet. Emphasis is placed on the use of standardized buffycoat depleted red cells or platelet concentrates for filtration, and the selection of leucocyte filters with high capacity and ease of bedside application. Leucocyte counts as low as 1-2 10(5) per unit are recommended after filtration in order to avoid HLA-antibody production. For bedside filtration, our choice was RC100 and PL100 (Pall) for red cells and platelets respectively. For laboratory use we prefer, for economic reasons, to use Sepacell R500 (Asahi) and Imugard IG500 (Terumo) for red cells and platelets respectively. Leucocyte-filtered blood products are considered indicated in all pre-transplant transfusions, in post-transplant HLA-sensitized patients, in other patients with febrile transfusion reactions, and in patients with an expected protracted platelet requirement. CMV antibody negative products are recommended for all immuno-deficient patients and pregnant women negative for CMV antibody. Irradiated blood products are used in the treatment of immuno-deficient patients receiving large amounts of blood, and in all severely immuno-compromised patients. In emergency situations where CMV antibody negative and/or irradiated blood products cannot be supplied, leucocyte filtration is suggested. PMID:2154061

  10. Ceramide and ceramide 1-phosphate are negative regulators of TNF-α production induced by lipopolysaccharide.

    PubMed

    Józefowski, Szczepan; Czerkies, Maciej; Łukasik, Anna; Bielawska, Alicja; Bielawski, Jacek; Kwiatkowska, Katarzyna; Sobota, Andrzej

    2010-12-01

    LPS is a constituent of cell walls of Gram-negative bacteria that, acting through the CD14/TLR4 receptor complex, causes strong proinflammatory activation of macrophages. In murine peritoneal macrophages and J774 cells, LPS at 1-2 ng/ml induced maximal TNF-α and MIP-2 release, and higher LPS concentrations were less effective, which suggested a negative control of LPS action. While studying the mechanism of this negative regulation, we found that in J774 cells, LPS activated both acid sphingomyelinase and neutral sphingomyelinase and moderately elevated ceramide, ceramide 1-phosphate, and sphingosine levels. Lowering of the acid sphingomyelinase and neutral sphingomyelinase activities using inhibitors or gene silencing upregulated TNF-α and MIP-2 production in J774 cells and macrophages. Accordingly, treatment of those cells with exogenous C8-ceramide diminished TNF-α and MIP-2 production after LPS stimulation. Exposure of J774 cells to bacterial sphingomyelinase or interference with ceramide hydrolysis using inhibitors of ceramidases also lowered the LPS-induced TNF-α production. The latter result indicates that ceramide rather than sphingosine suppresses TNF-α and MIP-2 production. Of these two cytokines, only TNF-α was negatively regulated by ceramide 1-phosphate as was indicated by upregulated TNF-α production after silencing of ceramide kinase gene expression. None of the above treatments diminished NO or RANTES production induced by LPS. Together the data indicate that ceramide negatively regulates production of TNF-α and MIP-2 in response to LPS with the former being sensitive to ceramide 1-phosphate as well. We hypothesize that the ceramide-mediated anti-inflammatory pathway may play a role in preventing endotoxic shock and in limiting inflammation. PMID:21041721

  11. Petunia × hybrida floral scent production is negatively affected by high-temperature growth conditions.

    PubMed

    Cna'ani, Alon; Mühlemann, Joelle K; Ravid, Jasmin; Masci, Tania; Klempien, Antje; Nguyen, Thuong T H; Dudareva, Natalia; Pichersky, Eran; Vainstein, Alexander

    2015-07-01

    Increasing temperatures due to changing global climate are interfering with plant-pollinator mutualism, an interaction facilitated mainly by floral colour and scent. Gas chromatography-mass spectroscopy analyses revealed that increasing ambient temperature leads to a decrease in phenylpropanoid-based floral scent production in two Petunia × hybrida varieties, P720 and Blue Spark, acclimated at 22/16 or 28/22 °C (day/night). This decrease could be attributed to down-regulation of scent-related structural gene expression from both phenylpropanoid and shikimate pathways, and up-regulation of a negative regulator of scent production, emission of benzenoids V (EOBV). To test whether the negative effect of increased temperature on scent production can be reduced in flowers with enhanced metabolic flow in the phenylpropanoid pathway, we analysed floral volatile production by transgenic 'Blue Spark' plants overexpressing CaMV 35S-driven Arabidopsis thaliana production of anthocyanin pigments 1 (PAP1) under elevated versus standard temperature conditions. Flowers of 35S:PAP1 transgenic plants produced the same or even higher levels of volatiles when exposed to a long-term high-temperature regime. This phenotype was also evident when analysing relevant gene expression as inferred from sequencing the transcriptome of 35S:PAP1 transgenic flowers under the two temperature regimes. Thus, up-regulation of transcription might negate the adverse effects of temperature on scent production. PMID:25402319

  12. Long-pulse production of high current negative ion beam by using actively temperature controlled plasma grid for JT-60SA negative ion source

    SciTech Connect

    Kojima, A.; Hanada, M.; Yoshida, M.; Umeda, N.; Hiratsuka, J.; Kashiwagi, M.; Tobari, H.; Watanabe, K.; Grisham, L. R.

    2015-04-08

    The temperature control system of the large-size plasma grid has been developed to realize the long pulse production of high-current negative ions for JT-60SA. By using this prototype system for the JT-60SA ion source, 15 A negative ions has been sustained for 100 s for the first time, which is three times longer than that obtained in JT-60U. In this system, a high-temperature fluorinated fluid with a high boiling point of 270 degree Celsius is circulated in the cooling channels of the plasma grids (PG) where a cesium (Cs) coverage is formed to enhance the negative ion production. Because the PG temperature control had been applied to only 10% of the extraction area previously, the prototype PG with the full extraction area (110 cm × 45 cm) was developed to increase the negative ion current in this time. In the preliminary results of long pulse productions of high-current negative ions at a Cs conditioning phase, the negative ion production was gradually degraded in the last half of 100 s pulse where the temperature of an arc chamber wall was not saturated. From the spectroscopic measurements, it was found that the Cs flux released from the wall might affect to the negative ion production, which implied the wall temperature should be kept low to control the Cs flux to the PG for the long-pulse high-current production. The obtained results of long-pulse production and the PG temperature control method contributes the design of the ITER ion source.

  13. Long-pulse production of high current negative ion beam by using actively temperature controlled plasma grid for JT-60SA negative ion source

    NASA Astrophysics Data System (ADS)

    Kojima, A.; Hanada, M.; Yoshida, M.; Umeda, N.; Hiratsuka, J.; Kashiwagi, M.; Tobari, H.; Watanabe, K.; Grisham, L. R.

    2015-04-01

    The temperature control system of the large-size plasma grid has been developed to realize the long pulse production of high-current negative ions for JT-60SA. By using this prototype system for the JT-60SA ion source, 15 A negative ions has been sustained for 100 s for the first time, which is three times longer than that obtained in JT-60U. In this system, a high-temperature fluorinated fluid with a high boiling point of 270 degree Celsius is circulated in the cooling channels of the plasma grids (PG) where a cesium (Cs) coverage is formed to enhance the negative ion production. Because the PG temperature control had been applied to only 10% of the extraction area previously, the prototype PG with the full extraction area (110 cm × 45 cm) was developed to increase the negative ion current in this time. In the preliminary results of long pulse productions of high-current negative ions at a Cs conditioning phase, the negative ion production was gradually degraded in the last half of 100 s pulse where the temperature of an arc chamber wall was not saturated. From the spectroscopic measurements, it was found that the Cs flux released from the wall might affect to the negative ion production, which implied the wall temperature should be kept low to control the Cs flux to the PG for the long-pulse high-current production. The obtained results of long-pulse production and the PG temperature control method contributes the design of the ITER ion source.

  14. Self-similarity of negative particle production from the Beam Energy Scan Program at STAR

    NASA Astrophysics Data System (ADS)

    Tokarev, Mikhail

    2015-11-01

    We present the spectra of negative charged particle production in Au + Au collisions from STAR for the first phase of the RHIC Beam Energy Scan Program measured over a wide range of collision energy sNN=7.7-200GeV, and transverse momentum of produced particle in different centralities at |η| < 0.5. The spectra demonstrate strong dependence on collision energy which enhances with pT. An indication of self-similarity of negative charged particle production in Au + Au collisions is found. The constituent energy loss as a function of energy and centrality of collisions and transverse momentum of inclusive particle was estimated in the z-scaling approach. The energy dependence of the model parameters - the fractal and fragmentation dimensions and “specific heat”, was studied.

  15. Negative-ion surface production in hydrogen plasmas: Determination of the negative-ion energy and angle distribution function using mass spectrometry

    NASA Astrophysics Data System (ADS)

    Dubois, J. P. J.; Achkasov, K.; Kogut, D.; Ahmad, A.; Layet, J. M.; Simonin, A.; Cartry, G.

    2016-05-01

    This work focuses on the understanding of the production mechanism of negative-ions on surface in low pressure plasmas of H2/D2. The negative ions are produced on a Highly Oriented Pyrolytic Graphite sample negatively biased with respect to plasma potential. The negative ions created under the positive ion bombardment are accelerated towards the plasma, self-extracted, and detected according to their energy and mass by a mass spectrometer placed in front of the sample. The shape of the measured Negative-Ion Energy Distribution Function (NIEDF) strongly differs from the NIEDF of the ions emitted by the sample because of the limited acceptance angle of the mass spectrometer. To get information on the production mechanisms, we propose a method to obtain the distribution functions in energy and angle (NIEADFs) of the negative-ions emitted by the sample. It is based on an a priori determination of the NIEADF and on an a posteriori validation of the choice by comparison of the modelled and experimental NIEDFs.

  16. Antennally mediated negative feedback regulation of pheromone production in the pine engraver beetle, Ips pini

    NASA Astrophysics Data System (ADS)

    Ginzel, Matthew D.; Bearfield, Jeremy C.; Keeling, Christopher I.; McCormack, Colin C.; Blomquist, Gary J.; Tittiger, Claus

    2007-01-01

    Bark beetles use monoterpenoid aggregation pheromones to coordinate host colonization and mating. These chemical signals are produced de novo in midgut cells via the mevalonate pathway, and pheromone production may be regulated by a negative feedback system mediated through the antennae. In this study, we explored the effect of antennectomy on pheromone production and transcript levels of key mevalonate pathway genes in juvenile hormone III-treated male pine engraver beetles, Ips pini (Say). Antennectomized males produced significantly greater amounts of pheromone than podectomized males and those with intact antennae. Likewise, mRNA levels of three mevalonate pathway genes important in pheromone biosynthesis were measured by quantitative real-time PCR and found to be induced to a greater extent with antennectomy, suggesting a transcriptional regulation of pheromone production.

  17. [Antimicrobial sensivity and ability to slime production of koagulaze-negative staphylococci].

    PubMed

    Szczuka, Ewa; Prawda-Zołotar, Jolanta; Nowakiewicz, Maryla; Kaznowski, Adam

    2011-01-01

    The aim of this study was to assess the ability of slime production ofcoagulase-negative staphylococci (CONS) and evaluate the susceptibility of bacteria to antibiotics. Strains were isolated from clinical specimens obtained from hospitalized patients. The most frequently isolated species were S. epidermidis (51%), S. hominis (18%), S. haemolyticus (13%). The result of this study shows that 61% of S.epidermidis produce slime on CRA (Congo red agar), whereas none of the tested S. haemolyticus strains has this ability. All examined strains were susceptible to vancomycin, linezolid and quinupristin/ dalfopristin. The majority of strains were susceptible to minocycline, fusid acid, nitrofurantoin and rifampicin. Sixty six percent of isolates were determined as methicillin-resistant coagulase-negative staphylococci. PMID:22184892

  18. Enhanced interannual precipitation variability increases plant functional diversity that in turn ameliorates negative impact on productivity.

    PubMed

    Gherardi, Laureano A; Sala, Osvaldo E

    2015-12-01

    Although precipitation interannual variability is projected to increase due to climate change, effects of changes in precipitation variance have received considerable less attention than effects of changes in the mean state of climate. Interannual precipitation variability effects on functional diversity and its consequences for ecosystem functioning are assessed here using a 6-year rainfall manipulation experiment. Five precipitation treatments were switched annually resulting in increased levels of precipitation variability while maintaining average precipitation constant. Functional diversity showed a positive response to increased variability due to increased evenness. Dominant grasses decreased and rare plant functional types increased in abundance because grasses showed a hump-shaped response to precipitation with a maximum around modal precipitation, whereas rare species peaked at high precipitation values. Increased functional diversity ameliorated negative effects of precipitation variability on primary production. Rare species buffered the effect of precipitation variability on the variability in total productivity because their variance decreases with increasing precipitation variance. PMID:26437913

  19. Production of pyruvate from mannitol by mannitol-assimilating pyruvate decarboxylase-negative Saccharomyces cerevisiae.

    PubMed

    Yoshida, Shiori; Tanaka, Hideki; Hirayama, Makoto; Murata, Kousaku; Kawai, Shigeyuki

    2015-01-01

    Mannitol is contained in brown macroalgae up to 33% (w/w, dry weight), and thus is a promising carbon source for white biotechnology. However, Saccharomyces cerevisiae, a key cell factory, is generally regarded to be unable to assimilate mannitol for growth. We have recently succeeded in producing S. cerevisiae that can assimilate mannitol through spontaneous mutations of Tup1-Cyc8, each of which constitutes a general corepressor complex. In this study, we demonstrate production of pyruvate from mannitol using this mannitol-assimilating S. cerevisiae through deletions of all 3 pyruvate decarboxylase genes. The resultant mannitol-assimilating pyruvate decarboxylase-negative strain produced 0.86 g/L pyruvate without use of acetate after cultivation for 4 days, with an overall yield of 0.77 g of pyruvate per g of mannitol (the theoretical yield was 79%). Although acetate was not needed for growth of this strain in mannitol-containing medium, addition of acetate had a significant beneficial effect on production of pyruvate. This is the first report of production of a valuable compound (other than ethanol) from mannitol using S. cerevisiae, and is an initial platform from which the productivity of pyruvate from mannitol can be improved. PMID:26588105

  20. The Role of Children's Negative Attributions on Depressive Symptoms: An Inherited Characteristic or a Product of the Early Environment?

    ERIC Educational Resources Information Center

    Lau, Jennifer Y. F.; Belli, Stefano D.; Gregory, Alice M.; Napolitano, Maria; Eley, Thalia C.

    2012-01-01

    Negative attributional style has been associated with depressive symptoms in children. Yet, it is unclear whether these cognitive biases reflect inherited characteristics of the broader depressive phenotype or are a product of children's environments. While existing data in adolescents show that negative attributions reflect a genetic…

  1. DCIR negatively regulates CpG-ODN-induced IL-1β and IL-6 production.

    PubMed

    Zhao, Xibao; Shen, Yaping; Hu, Weiwei; Chen, Junru; Wu, Tian; Sun, Xiaoqiang; Yu, Juan; Wu, Tingting; Chen, Weilin

    2015-12-01

    C-type lectin receptors (CLR) are a diverse family of proteins mainly expressed on antigen-presenting cells (APC). As antigen-uptake and signaling receptors, CLR modulate immune responses of APC. The dendritic cell immunoreceptor (DCIR) is a member of CLR and has an immunoreceptor tyrosine based inhibitory motif (ITIM) in cytoplasmic tail, which is believed to play a negative role in cellular responses after antigen exposure. In addition to pathogen recognition, DCIR has been shown to be pivotal in preventing autoimmune disease by controlling dendritic cell proliferation. However, much less is known about the role of DCIR in innate immunity and its crosstalk with the Toll like receptors (TLR) pathway. In this study, we demonstrate that CpG-ODN stimulation can promote DCIR expression in macrophages and DCIR triggering inhibits the production of CpG-ODN-induced proinflammatory cytokines. We further confirm that siRNA-mediated knockdown of DCIR expression enhances CpG-ODN-induced phosphorylation of Erk1/2, JNK1/2 and p38 in macrophages. Collectively, these results indicate that DCIR is a negatively regulator in TLR9-mediated innate immune response. PMID:26514427

  2. Improving efficiency of negative ion production in ion source with saddle antenna

    SciTech Connect

    Dudnikov, V. Johnson, R. P.; Murrey, S.; Pinnisi, T.; Piller, C.; Santana, M.; Stockli, M.; Welton, R.; Johnson, C.; Turvey, M.

    2014-02-15

    Extraction of negative ions from a saddle antenna radio-frequency surface plasma source is considered. Several versions of new plasma generators with different antennas and magnetic field configurations were tested in the smal Oak Ridge National Laboratory Spallation Neutron Source Test Stand. The efficiency of positive ion generation in plasma has been improved to 200 mA/cm{sup 2} kW from 2.5 mA/cm{sup 2} kW. A small oven was developed for cesiation by cesium compounds and alloy decomposition. After cesiation, a current of negative ions to the collector was increased from 1 mA to 10 mA with 1.5 kW RF power in the plasma and longitudinal magnetic field B{sub l} ∼ 250 G. The specific efficiency of H{sup −} production was increased to 20 mA/cm{sup 2} kW from 2.5 mA/cm{sup 2} kW.

  3. Multidrug-resistant Gram-negative bacteria: a product of globalization.

    PubMed

    Hawkey, P M

    2015-04-01

    Global trade and mobility of people has increased rapidly over the last 20 years. This has had profound consequences for the evolution and the movement of antibiotic resistance genes. There is increasing exposure of populations all around the world to resistant bacteria arising in the emerging economies. Arguably the most important development of the last two decades in the field of antibiotic resistance is the emergence and spread of extended-spectrum β-lactamases (ESBLs) of the CTX-M group. A consequence of the very high rates of ESBL production among Enterobacteriaceae in Asian countries is that there is a substantial use of carbapenem antibiotics, resulting in the emergence of plasmid-mediated resistance to carbapenems. This article reviews the emergence and spread of multidrug-resistant Gram-negative bacteria, focuses on three particular carbapenemases--imipenem carbapenemases, Klebsiella pneumoniae carbapenemase, and New Delhi metallo-β-lactamase--and highlights the importance of control of antibiotic use. PMID:25737092

  4. CD45 negatively regulates tumour necrosis factor and interleukin-6 production in dendritic cells.

    PubMed

    Piercy, Jenny; Petrova, Svetla; Tchilian, Elma Z; Beverley, Peter C L

    2006-06-01

    CD45 is known to regulate signalling through many different surface receptors in diverse haemopoietic cell types. Here we report for the first time that CD45-/- bone marrow dendritic cells (BMDC) are more activated than CD45+/+ cells and that tumour necrosis factor (TNF) and interleukin-6 (IL-6) production by BMDC and splenic dendritic cells (sDC), is increased following stimulation via Toll-like receptor (TLR)3 and TLR9. Nuclear factor-kappaB activation, an important downstream consequence of TLR3 and TLR9 signalling, is also increased in CD45-/- BMDC. BMDC of CD45-/- mice also produce more TNF and IL-6 following stimulation with the cytokines TNF and interferon-alpha. These results show that TLR signalling is increased in CD45-/- dendritic cells and imply that CD45 is a negative regulator of TLR and cytokine receptor signalling in dendritic cells. PMID:16771860

  5. Negative ion production in the RF multiaperture surface-plasma source

    NASA Astrophysics Data System (ADS)

    Abdrashitov, G.; Belchenko, Yu.; Dranichnikov, A.; Ivanov, A.; Gorbovsky, A.; Kapitonov, V.; Kolmogorov, V.; Kondakov, A.; Konstantinov, S.; Sanin, A.; Selivanov, A.; Selivanov, P.; Shikhovtsev, I.; Sotnikov, O.; Stupishin, N.; Tiunov, M.; Binderbauer, M.; Putvinski, S.; Smirnov, A.; Sevier, L.

    2015-04-01

    The experiments on negative hydrogen ion beam production in a multi-aperture long-pulse surface-plasma source are described. H- ions are produced on the surface of a plasma grid covered by cesium and illuminated by fast plasma particles. The source uses a radio-frequency driver to generate plasma. A composite magnet system made of external permanent magnets confines and filters electrons in the plasma region, and deflects them in the extraction area. A multiaperture, multi-electrode ion optical system is used for beam formation. The electrode heating and cooling during long pulses is accomplished by circulating a heat transfer fluid through channels drilled in the electrodes bodies. H- ions extraction through a single aperture and 21 apertures was performed and studied. A stable H- beam with the current up to 0.7 A, energy up to 74 kV, and pulse duration up to 7 s was routinely obtained

  6. Negative ion production in the RF multiaperture surface-plasma source

    SciTech Connect

    Abdrashitov, G.; Belchenko, Yu. Dranichnikov, A.; Gorbovsky, A.; Kapitonov, V.; Kolmogorov, V.; Kondakov, A.; Konstantinov, S.; Sanin, A.; Selivanov, A.; Selivanov, P.; Shikhovtsev, I.; Stupishin, N.; Tiunov, M.; Ivanov, A.; Sotnikov, O.; Binderbauer, M.; Putvinski, S.; Smirnov, A.; Sevier, L.

    2015-04-08

    The experiments on negative hydrogen ion beam production in a multi-aperture long-pulse surface-plasma source are described. H- ions are produced on the surface of a plasma grid covered by cesium and illuminated by fast plasma particles. The source uses a radio-frequency driver to generate plasma. A composite magnet system made of external permanent magnets confines and filters electrons in the plasma region, and deflects them in the extraction area. A multiaperture, multi-electrode ion optical system is used for beam formation. The electrode heating and cooling during long pulses is accomplished by circulating a heat transfer fluid through channels drilled in the electrodes bodies. H- ions extraction through a single aperture and 21 apertures was performed and studied. A stable H- beam with the current up to 0.7 A, energy up to 74 kV, and pulse duration up to 7 s was routinely obtained.

  7. TRIM13 Is a Negative Regulator of MDA5-Mediated Type I Interferon Production

    PubMed Central

    Narayan, Kavitha; Waggoner, Lisa; Pham, Serena T.; Hendricks, Gabriel L.; Waggoner, Stephen N.; Conlon, Joseph; Wang, Jennifer P.

    2014-01-01

    ABSTRACT Retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5) are essential intracellular detectors of viral RNA. They contribute to the type I interferon (IFN) response that is crucial for host defense against viral infections. Given the potent antiviral and proinflammatory activities elicited by the type I IFNs, induction of the type I IFN response is tightly regulated. Members of the tripartite motif (TRIM) family of proteins have recently emerged as key regulators of antiviral immunity. We show that TRIM13, an E3 ubiquitin ligase, is expressed in immune cells and is upregulated in bone marrow-derived macrophages upon stimulation with inducers of type I IFN. TRIM13 interacts with MDA5 and negatively regulates MDA5-mediated type I IFN production in vitro, acting upstream of IFN regulatory factor 3. We generated Trim13−/− mice and show that upon lethal challenge with encephalomyocarditis virus (EMCV), which is sensed by MDA5, Trim13−/− mice produce increased amounts of type I IFNs and survive longer than wild-type mice. Trim13−/− murine embryonic fibroblasts (MEFs) challenged with EMCV or poly(I·C) also show a significant increase in beta IFN (IFN-β) levels, but, in contrast, IFN-β responses to the RIG-I-detected Sendai virus were diminished, suggesting that TRIM13 may play a role in positively regulating RIG-I function. Together, these results demonstrate that TRIM13 regulates the type I IFN response through inhibition of MDA5 activity and that it functions nonredundantly to modulate MDA5 during EMCV infection. IMPORTANCE The type I interferon (IFN) response is crucial for host defense against viral infections, and proper regulation of this pathway contributes to maintaining immune homeostasis. Retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5) are intracellular detectors of viral RNA that induce the type I IFN response. In this study, we show that expression of the

  8. Positive and negative ion beam merging system for neutral beam production

    DOEpatents

    Leung, Ka-Ngo; Reijonen, Jani

    2005-12-13

    The positive and negative ion beam merging system extracts positive and negative ions of the same species and of the same energy from two separate ion sources. The positive and negative ions from both sources pass through a bending magnetic field region between the pole faces of an electromagnet. Since the positive and negative ions come from mirror image positions on opposite sides of a beam axis, and the positive and negative ions are identical, the trajectories will be symmetrical and the positive and negative ion beams will merge into a single neutral beam as they leave the pole face of the electromagnet. The ion sources are preferably multicusp plasma ion sources. The ion sources may include a multi-aperture extraction system for increasing ion current from the sources.

  9. A new grid-type electron filter for volume-production negative-ion source

    NASA Astrophysics Data System (ADS)

    Rafalskyi, D. V.; Dudin, S. V.

    2012-03-01

    A new system providing continuous generation of broad negative-ion beam is described and characterized. The key element of the system is the grid-type electron filter allowing the formation without magnetic field of a stationary highly electronegative plasma which can be biased negatively with respect to a relatively high-area electrode that allows to extract the negative ions. Measurements of negative-ion energy distribution functions conducted using a magnetically filtered energy analyzer show broad (250 mm) negative-ion beam formation with controllable energy starting from several eV. A conclusion is made about the possibility of practical application of the grid-type electron filter in negative ion sources for electric propulsion and etching technologies.

  10. Ifluence of outer electrode material on ozone production in coaxial negative corona discharge fed by oxygen

    NASA Astrophysics Data System (ADS)

    Orszagh, J.; Skalny, J. D.; Mason, N. J.

    2008-07-01

    The "electric odour", observed by Van Marum when oxygen was passing trough electric spark in 1785, has been later (1839), identified by Ch. F. Schonbeim as a new chemical compound named ozone (Stolarski 1999). Almost from those times ozone is widely used chemical compound. The effect of outer electrode material on the ozone production in negative corona discharge have been studied. Two electrodes with the same dimensions were used in the experiment. One was made of stainless steel other one of brass. First the outer electrode was mechanically cleaned to remove the layer of oxides. The reactor have been filled by pure oxygen and closed. Then the measurement (1 hour measurement of discharge current at the constant voltage and time dependence of ozone concentration in the reactor) was repeated 5 times without cleaning the surface to see the ageing effects. Especially the influence of electrode oxidation on ozone concentration was studied. The experiments have been carried out at atmospheric pressure and ambient temperature. The ozone concentration was measured by UV spectroscopy method directly in the discharge reactor. As one can expect the brass surface was oxidizing faster. After five measurements the electrode surface was covered by layer of greenish oxides. On the other hand the steel electrode surface had no visible oxides layer. The oxidation of the outer electrode had little systematic effect on the ozone concentration but in case of brass electrode the results were scattered in the range from 8000 ppm to 15000 ppm of ozone. It seems that the more oxides are created on the surface the less ozone is produced or the faster the ozone decomposition processes are (see Fig. 1). On the other hand in case of stainless steel electrode the ozone concentrations were comparable in all 5 measurements. Overall ozone concentration was higher in steel electrode. Figure 1: Time dependence of ozone concentration.

  11. Production of intense beams of polarized negative hydrogen ions by double charge exchange in alkali vapour

    NASA Astrophysics Data System (ADS)

    Gruëbler, W.; Schmelzbach, P. A.

    1983-07-01

    The intensity of the polarized negative hydrogen ion beam of the ETHZ atomic beam polarized ion source has been substantially improved by a new double charge exchange device. Increasing the diameter of the charge exchange canal to 1.4 cm results in a beam output of the source of 6 μA of polarized negative hydrogen ions. Further improvements of the charge exchanger are proposed and discussed. With an updated design of the atomic beam apparatus, beams of 0.5 mA polarized negative hydrogen ions may be obtained from such a source.

  12. Rhesus Negative Woman Transfused With Rhesus Positive Blood: Subsequent Normal Pregnancy Without Anti D production.

    PubMed

    Maya, E T; Buntugu, K A; Pobee, F; Srofenyoh, E K

    2015-03-01

    Clinicians sometimes are confronted with the challenge of transfusing haemorrhaging Rhesus (Rh) D negative patients with Rh D positive blood to save their lives. There are concerns about alloimmunization and future haemolytic disease of the newborn in women of the reproductive age. Another fear is transfusion reaction if they receive another Rh D positive blood in future. We present a 32-year-old Rh D negative woman, who had postpartum haemorrhage in her first pregnancy and was transfused with Rh D positive blood because of unavailability of Rh D negative blood. She did not receive anti D immunoglobin but subsequently had a normal term pregnancy of an Rh positive fetus without any detectable anti D antibodies throughout the pregnancy. In life threatening situations from obstetric haemorrhage, transfusion of Rh D negative women with Rh D positive blood should be considered as the last resort. PMID:26339087

  13. Design and fabrication of a large magnetic cusp type of plasma generator for the production of negative ions

    SciTech Connect

    Biagi, L.A.; Ehlers, K.W.; Leung, K.N.; Matuk, C.A.; Moon, S.D.; Paterson, J.A.

    1981-10-01

    The design and fabrication techniques for a large magnetic bucket type of plasma source designed for the production of negative ions by surface conversion are described. These include the design of a converter structure, cesium oven and injector, variable aperture electrode, accelerator section as well as the features of the magnetic cusp geometry employed.

  14. Effect of nickel grid parameters on production of negative hydrogen ions

    SciTech Connect

    Oohara, W.; Yokoyama, H.; Takeda, Toshiaki; Maetani, Y.; Takeda, Takashi; Kawata, K.

    2014-06-15

    Negative hydrogen ions are produced by plasma-assisted catalytic ionization using a nickel grid. When positive ions passing through the grid are decelerated by an electric field, the extraction current density of passing positive ions is sharply reduced by neutralization and negative ionization of the ions. This phenomenon is found to depend on the specific surface area of the grid and the current density.

  15. Molecular and negative ion production by a standard electron cyclotron resonance ion source

    SciTech Connect

    Racz, R.; Biri, S.; Juhasz, Z.; Sulik, B.

    2012-02-15

    Molecular and negative ion beams, usually produced in special ion sources, play an increasingly important role in fundamental and applied atomic physics. The ATOMKI-ECRIS is a standard ECR ion source, designed to provide highly charged ion (HCI) plasmas and beams. In the present work, H{sup -}, O{sup -}, OH{sup -}, O{sub 2}{sup -}, C{sup -}, C{sub 60}{sup -} negative ions and H{sub 2}{sup +}, H{sub 3}{sup +}, OH{sup +}, H{sub 2}O{sup +}, H{sub 3}O{sup +}, O{sub 2}{sup +} positive molecular ions were generated in this HCI-ECRIS. Without any major modification in the source and without any commonly applied tricks (such as usage of cesium or magnetic filter), negative ion beams of several {mu}A and positive molecular ion beams in the mA range were successfully obtained.

  16. Effect of high energy electrons on H- production and destruction in a high current DC negative ion source for cyclotron

    NASA Astrophysics Data System (ADS)

    Onai, M.; Etoh, H.; Aoki, Y.; Shibata, T.; Mattei, S.; Fujita, S.; Hatayama, A.; Lettry, J.

    2016-02-01

    Recently, a filament driven multi-cusp negative ion source has been developed for proton cyclotrons in medical applications. In this study, numerical modeling of the filament arc-discharge source plasma has been done with kinetic modeling of electrons in the ion source plasmas by the multi-cusp arc-discharge code and zero dimensional rate equations for hydrogen molecules and negative ions. In this paper, main focus is placed on the effects of the arc-discharge power on the electron energy distribution function and the resultant H- production. The modelling results reasonably explains the dependence of the H- extraction current on the arc-discharge power in the experiments.

  17. Twenty Five Years of Vibrational Kinetics and Negative Ion Production in H2 Plasmas: Modelling Aspects

    SciTech Connect

    Capitelli, M.; De Pascale, O.; Diomede, P.; Gorse, C.; Longo, S.; Pagano, D.; Gicquel, A.; Hassouni, K.

    2005-04-06

    Different approaches to study vibrational kinetics coupled to electron one for modeling different kinds of negative ion sources are presented. In particular two types of sources are investigated. The first one is a classical negative ion source in which the plasma is generated by thermoemitted electrons; in the second one, electrons already present in the mixture are accelerated by an RF field to sufficiently high energy to ionize the gas molecules. For the first kind of ion source a new computational scheme is presented to couple heavy particle and electron kinetics. Moreover models developed for an RF inductive discharge and for a parallel plate discharge are described.

  18. The adhesion GPCR BAI1 mediates macrophage ROS production and microbicidal activity against Gram-negative bacteria

    PubMed Central

    Billings, Emily A.; Lee, Chang Sup; Owen, Katherine A.; D’Souza, Ryan S.; Ravichandran, Kodi S.; Casanova, James E.

    2016-01-01

    The detection of microbes and initiation of an innate immune response occur through pattern recognition receptors (PRRs), which are critical for the production of inflammatory cytokines and activation of the cellular microbicidal machinery. In particular, the production of reactive oxygen species (ROS) by the NADPH oxidase complex is a critical component of the macrophage bactericidal machinery. We previously characterized brain-specific angiogenesis inhibitor 1 (BAI1), a member of the adhesion family of G protein (heterotrimeric guanine nucleotide–binding protein)–coupled receptors (GPCRs), as a PRR that mediates the selective phagocytic uptake of Gram-negative bacteria by macrophages. We showed that BAI1 promoted phagosomal ROS production through activation of the Rho family guanosine triphosphatase (GTPase) Rac1, thereby stimulating NADPH oxidase activity. Primary BAI1-deficient macrophages exhibited attenuated Rac GTPase activity and reduced ROS production in response to several Gram-negative bacteria, resulting in impaired microbicidal activity. Furthermore, in a peritoneal infection model, BAI1-deficient mice exhibited increased susceptibility to death by bacterial challenge because of impaired bacterial clearance. Together, these findings suggest that BAI1 mediates the clearance of Gram-negative bacteria by stimulating both phagocytosis and NADPH oxidase activation, thereby coupling bacterial detection to the cellular microbicidal machinery. PMID:26838550

  19. Negative ion surface production on carbon materials in hydrogen plasma: a thermodesorption analysis of carbon surface states

    NASA Astrophysics Data System (ADS)

    Cartry, Gilles; Achkasov, Kostiantyn; Pardanaud, Cédric; Layet, Jean-Marc; Simonin, Alain; Gicquel, Alix; Saidi, Othmen; Bisson, Régis; Angot, Thierry; PIIM Collaboration; IRFM Collaboration; LSPM Collaboration

    2014-10-01

    Negative ion surface production in plasmas has been studied in the context of fusion where H-surface production in cesium-seeded plasmas is of a primary interest for neutral beam injection devices. Although surface production is much lower in Cs-free plasmas, it may be non-negligible. Indeed it has been observed that significant numbers of H-ions can be created on a graphite surface upon positive ion bombardment in H2 plasmas. Graphite material has been compared to a large variety of diamond layers, in particular poly-crystalline boron-doped and non-doped diamond thin films. It has been shown an enhancement of the negative-ion yield by a factor 5 for diamond materials at high temperature, while the yield continuously decreases for graphite. The difference is due to the different properties of the pristine materials but also to the modifications bring by the plasma to the materials during exposure. In order to study in detail these modifications, plasma exposed samples have been analyzed by Raman spectroscopy and Temperature Programmed Desorption (TPD). These diagnostics helped to trace the surface state changes of the materials and identify the reasons for the elevated negative ion production at high temperature on diamonds.

  20. Gram-Positive and Gram-Negative Bacteria Do Not Trigger Monocytic Cytokine Production through Similar Intracellular Pathways

    PubMed Central

    Rabehi, Lila; Irinopoulou, Théano; Cholley, Béatrice; Haeffner-Cavaillon, Nicole; Carreno, Marie-Paule

    2001-01-01

    Toll-like receptors (TLRs) are involved in human monocyte activation by lipopolysaccharide (LPS) and Staphylococcus aureus Cowan (SAC), suggesting that gram-positive and gram-negative bacteria may trigger similar intracellular events. Treatment with specific kinase inhibitors prior to cell stimulation dramatically decreased LPS-induced cytokine production. Blocking of the p38 pathway prior to LPS stimulation decreased interleukin-1α (IL-1α), IL-1ra, and tumor necrosis factor alpha (TNF-α) production, whereas blocking of the ERK1/2 pathways inhibited IL-1α, IL-1β, and IL-1ra but not TNF-α production. When cells were stimulated by SAC, inhibition of the p38 pathway did not affect cytokine production, whereas only IL-1α production was decreased in the presence of ERK kinase inhibitor. We also demonstrated that although LPS and SAC have been shown to bind to CD14 before transmitting signals to TLR4 and TLR2, respectively, internalization of CD14 occurred only in monocytes triggered by LPS. Pretreatment of the cells with SB203580, U0126, or a mixture of both inhibitors did not affect internalization of CD14. Altogether, these results suggest that TLR2 signaling does not involve p38 mitogen-activated protein kinase signaling pathways, indicating that divergent pathways are triggered by gram-positive and gram-negative bacteria, thereby inducing cytokine production. PMID:11402003

  1. Positive and negative singly charged ion production of a laser induced plasma using a capillary graphite target.

    PubMed

    Saquilayan, G Q; Wada, M

    2016-02-01

    A new type of laser ion source is being developed aiming at the production of positive and negative singly charged ions using a capillary graphite target structure. The initial results of the laser plasma produced inside of the 10 mm diameter conduit indicated the formation of the secondary charged particle production inside the target. A high speed camera clearly recorded the plasma plume expansion inside the target. The time-of-flight spectrum of the laser produced plasma in vacuum showed that the signal of the positive ions formed two peaks as the laser power density exceeded 10 GW/cm(2). The addition of neutral gas to the system produced a signal corresponding to negative ions after the positive signal. PMID:26931968

  2. Negative ion production and beam extraction processes in a large ion source (invited)

    NASA Astrophysics Data System (ADS)

    Tsumori, K.; Ikeda, K.; Nakano, H.; Kisaki, M.; Geng, S.; Wada, M.; Sasaki, K.; Nishiyama, S.; Goto, M.; Serianni, G.; Agostinetti, P.; Sartori, E.; Brombin, M.; Veltri, P.; Wimmer, C.; Nagaoka, K.; Osakabe, M.; Takeiri, Y.; Kaneko, O.

    2016-02-01

    Recent research results on negative-ion-rich plasmas in a large negative ion source have been reviewed. Spatial density and flow distributions of negative hydrogen ions (H-) and positive hydrogen ions together with those of electrons are investigated with a 4-pin probe and a photodetachment (PD) signal of a Langmuir probe. The PD signal is converted to local H- density from signal calibration to a scanning cavity ring down PD measurement. Introduction of Cs changes the slope of plasma potential local distribution depending upon the plasma grid bias. A higher electron density H2 plasma locally shields the bias potential and behaves like a metallic free electron gas. On the other hand, the bias and extraction electric fields penetrate in a Cs-seeded electronegative plasma even when the electron density is similar. Electrons are transported by the penetrated electric fields from the driver region along and across the filter and electron deflection magnetic fields. Plasma ions exhibited a completely different response against the penetration of electric fields.

  3. Negative ion production and beam extraction processes in a large ion source (invited).

    PubMed

    Tsumori, K; Ikeda, K; Nakano, H; Kisaki, M; Geng, S; Wada, M; Sasaki, K; Nishiyama, S; Goto, M; Serianni, G; Agostinetti, P; Sartori, E; Brombin, M; Veltri, P; Wimmer, C; Nagaoka, K; Osakabe, M; Takeiri, Y; Kaneko, O

    2016-02-01

    Recent research results on negative-ion-rich plasmas in a large negative ion source have been reviewed. Spatial density and flow distributions of negative hydrogen ions (H(-)) and positive hydrogen ions together with those of electrons are investigated with a 4-pin probe and a photodetachment (PD) signal of a Langmuir probe. The PD signal is converted to local H(-) density from signal calibration to a scanning cavity ring down PD measurement. Introduction of Cs changes the slope of plasma potential local distribution depending upon the plasma grid bias. A higher electron density H2 plasma locally shields the bias potential and behaves like a metallic free electron gas. On the other hand, the bias and extraction electric fields penetrate in a Cs-seeded electronegative plasma even when the electron density is similar. Electrons are transported by the penetrated electric fields from the driver region along and across the filter and electron deflection magnetic fields. Plasma ions exhibited a completely different response against the penetration of electric fields. PMID:26932108

  4. Progress in long-pulse production of powerful negative ion beams for JT-60SA and ITER

    NASA Astrophysics Data System (ADS)

    Kojima, A.; Umeda, N.; Hanada, M.; Yoshida, M.; Kashiwagi, M.; Tobari, H.; Watanabe, K.; Akino, N.; Komata, M.; Mogaki, K.; Sasaki, S.; Seki, N.; Nemoto, S.; Shimizu, T.; Endo, Y.; Ohasa, K.; Dairaku, M.; Yamanaka, H.; Grisham, L. R.

    2015-06-01

    Significant progress in the extension of pulse durations of powerful negative ion beams has been made to realize the neutral beam injectors for JT-60SA and ITER. In order to overcome common issues of the long-pulse production/acceleration of negative ion beams in JT-60SA and ITER, new technologies have been developed in the JT-60SA ion source and the MeV accelerator in Japan Atomic Energy Agency. As for the long-pulse production of high-current negative ions for the JT-60SA ion source, the pulse durations have been successfully increased from 30 s at 13 A on JT-60U to 100 s at 15 A by modifying the JT-60SA ion source, which satisfies the required pulse duration of 100 s and 70% of the rated beam current for JT-60SA. This progress was based on the R&D efforts for the temperature control of the plasma grid and uniform negative ion productions with the modified tent-shaped filter field configuration. Moreover, each parameter of the required beam energy, current and pulse has been achieved individually by these R&D efforts. The developed techniques are useful to design the ITER ion source because the sustainment of the caesium coverage in the large extraction area is one of the common issues between JT-60SA and ITER. As for the long-pulse acceleration of high power density beams in the MeV accelerator for ITER, the pulse duration of MeV-class negative ion beams has been extended by more than 2 orders of magnitude by modifying the extraction grid with a high cooling capability and a high transmission of negative ions. A long-pulse acceleration of 60 s has been achieved at 70 MW m-2 (683 keV, 100 A m-2) which has reached the power density of JT-60SA level of 65 MW m-2. No degradations of the voltage holding capability of the acceleration voltage and the beam optics due to the distortion of the acceleration grids have been observed in this power density level. These results are the longest pulse durations of high-current and high-power-density negative ion beams in the

  5. 77 FR 35061 - Roseburg Forest Products Composite Panels Division Missoula, Montana; Notice of Negative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-12

    ... former workers of Roseburg Forest Products, Composite Panels Division, Missoula, Montana (subject firm). The Department's Notice was published in the Federal Register on March 26, 2012 (77 FR 17524). The... Employment and Training Administration Roseburg Forest Products Composite Panels Division Missoula,...

  6. 77 FR 27085 - TMI Forest Products, Inc., Crane Creek Division, Morton, WA; Notice of Negative Determination...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-08

    ... Determination was published in the Federal Register on March 6, 2012 (77 FR 13355). Pursuant to 29 CFR 90.18(c... Employment and Training Administration TMI Forest Products, Inc., Crane Creek Division, Morton, WA; Notice of... (TAA), applicable to workers and former workers of TMI Forest Products, Inc., Crane Creek...

  7. Molecular Characterization of Salmonella enterica Serovar Aberdeen Negative for H2S Production in China.

    PubMed

    Wu, Fuli; Xu, Xuebin; Xie, Jing; Yi, Shengjie; Wang, Jian; Yang, Xiaoxia; Yang, Chaojie; Liang, Beibei; Ma, Qiuxia; Li, Hao; Song, Hongbin; Qiu, Shaofu

    2016-01-01

    Salmonella enterica infections continue to be a significant burden on public health worldwide. The ability of S. enterica to produce hydrogen sulfide (H2S) is an important phenotypic characteristic used to screen and identify Salmonella with selective medium; however, H2S-negative Salmonella have recently emerged. In this study, the H2S phenotype of Salmonella isolates was confirmed, and the selected isolates were subjected to antimicrobial susceptibility testing and molecular identification by multilocus sequence typing, pulsed-field gel electrophoresis, and clustered regularly interspaced short palindromic repeat (CRISPR) analysis. The phs genetic operon was also analyzed. A total of 160 S. enterica serovar Aberdeen isolates were detected between 2005 and 2013 in China. Of them, seven non-H2S-producing isolates were detected. Notably, four samples yielded four pairs of isolates with different H2S phenotypes, simultaneously. The data demonstrated that H2S-negative isolates were genetically closely related to H2S-positive isolates. Three new spacers (Abe1, Abe2, and Abe3) were identified in CRISPR locus 1 in four pairs of isolates with different H2S phenotypes from the same samples. Sequence analysis revealed a new nonsense mutation at position 208 in the phsA gene of all non-H2S-producing isolates. Additionally, we describe a new screening procedure to avoid H2S-negative Salmonella, which would normally be overlooked during laboratory and hospital screening. The prevalence of this pathogen may be underestimated; therefore, it is important to focus on improving surveillance of this organism to control its spread. PMID:27552230

  8. Molecular Characterization of Salmonella enterica Serovar Aberdeen Negative for H2S Production in China

    PubMed Central

    Yi, Shengjie; Wang, Jian; Yang, Xiaoxia; Yang, Chaojie; Liang, Beibei; Ma, Qiuxia; Li, Hao; Song, Hongbin; Qiu, Shaofu

    2016-01-01

    Salmonella enterica infections continue to be a significant burden on public health worldwide. The ability of S. enterica to produce hydrogen sulfide (H2S) is an important phenotypic characteristic used to screen and identify Salmonella with selective medium; however, H2S-negative Salmonella have recently emerged. In this study, the H2S phenotype of Salmonella isolates was confirmed, and the selected isolates were subjected to antimicrobial susceptibility testing and molecular identification by multilocus sequence typing, pulsed-field gel electrophoresis, and clustered regularly interspaced short palindromic repeat (CRISPR) analysis. The phs genetic operon was also analyzed. A total of 160 S. enterica serovar Aberdeen isolates were detected between 2005 and 2013 in China. Of them, seven non-H2S-producing isolates were detected. Notably, four samples yielded four pairs of isolates with different H2S phenotypes, simultaneously. The data demonstrated that H2S-negative isolates were genetically closely related to H2S-positive isolates. Three new spacers (Abe1, Abe2, and Abe3) were identified in CRISPR locus 1 in four pairs of isolates with different H2S phenotypes from the same samples. Sequence analysis revealed a new nonsense mutation at position 208 in the phsA gene of all non-H2S-producing isolates. Additionally, we describe a new screening procedure to avoid H2S-negative Salmonella, which would normally be overlooked during laboratory and hospital screening. The prevalence of this pathogen may be underestimated; therefore, it is important to focus on improving surveillance of this organism to control its spread. PMID:27552230

  9. An unexpected negative influence of light intensity on hydrogen production by dark fermentative bacteria Clostridium beijerinckii.

    PubMed

    Zagrodnik, R; Laniecki, M

    2016-01-01

    The role of light intensity on biohydrogen production from glucose by Clostridium beijerinckii, Clostridium acetobutylicum, and Rhodobacter sphaeroides was studied to evaluate the performance and possible application in co-culture fermentation system. The applied source of light had spectrum similar to the solar radiation. The influence of light intensity on hydrogen production in dark process by C. acetobutylicum was negligible. In contrast, dark fermentation by C. beijerinckii bacteria showed a significant decrease (83%) in produced hydrogen at light intensity of 540W/m(2). Here, the redirection of metabolism from acetic and butyric acid formation towards lactic acid was observed. This not yet reported effect was probably caused by irradiation of these bacteria by light within UVA range, which is an important component of the solar radiation. The excessive illumination with light of intensity higher than 200W/m(2) resulted in decrease in hydrogen production with photofermentative bacteria as well. PMID:26602144

  10. Photodetachment diagnostics of a volume production type negative ion source with a diode-laser

    SciTech Connect

    Matsuda, Y.; Kasuya, T.; Takahashi, H.; Wada, M.; Nishiura, M.

    2008-02-15

    Time evolution of photodetachment perturbation signal induced by a diode laser was observed in an O{sub 2} plasma. Photodetachment current collected by a Langmuir probe was directly measured and recorded by a digital oscilloscope. After integrating the recorded signal data, the waveform of the photodetachment current showed a time dependence resembling an error function. The waveform had changed its shape in accordance as the position between the probe and the laser beam axis was changed. These characteristics of the photodetachment signal are well explained by a diffusion model. The method has the possibility to yield information on various negative ion containing plasmas, but requires quiescence in the electron saturation current with the fluctuation level less than 10{sup -4}.

  11. The production and destruction of negative ions. Progress report, September 1, 1992--August 31, 1993

    SciTech Connect

    Pegg, D.J.

    1993-04-01

    Single photon absorption-single electron detachment from few-electron atomic negative ions was studied. A crossed beam apparatus is being used to perform energy- and angle-resolved photoelectron spectroscopic measurements following photodetachment. Forward-directed electrons were collected and energy analyzed. The kinetic energies and yields of the photoelectrons were obtained by fitting the spectral peaks to Gaussian functions. Electron affinities, asymmetry parameters and cross sections are determined from these measurements. A ratio method in which the cross section for the ion of interest is measured relative to that of a reference ion was used. The study of the photodetachment of Li{sup {minus}} was completed, and attention has turned to the photodetachment of the stable ion B{sup {minus}} and the metastable ion Be{sup {minus}}.

  12. Effect of Art Production on Negative Mood: A Randomized, Controlled Trial

    ERIC Educational Resources Information Center

    Bell, Chloe E.; Robbins, Steven J.

    2007-01-01

    Art therapists have long held that art production causes reductions in stress and elevations in mood (Rubin, 1999). The authors examined this claim in a randomized, controlled trial. Fifty adults between the ages of 18 and 30 were randomly assigned to either create an art work or to view and sort a series of art prints. Three measures of overall…

  13. AmyR is a novel negative regulator of amylovoran production in Erwinia amylovora

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have previously reported the characterization of an orphan gene ybjN from Escherichia coli. In this study, we attempted to understand the role of amyR in Erwinia amylovora, a functionally conserved homolog of E. coli ybjN. As reported earlier, amylovoran production in the amyR knockout mutant is ...

  14. Subthreshold Pion Production in the Reaction Lanthanum -139 + LANTHANUM-139 ---> Positive Pion, Negative Pion + Chi.

    NASA Astrophysics Data System (ADS)

    Miller, Jack

    We have measured charged pion production in the reaction ^{139}La + ^{139}Latopi ^{+/-} + X at three beam energies (246, 183 and 138 MeV/nucleon) below the nucleon-nucleon threshold. Associated multiplicity for charged participants was obtained using a 110-element scintillator multiplicity array. Data were taken over the angular range of 21 ^circ-67^circ in the laboratory (equivalent to 30^ circ-90^circ in the center of mass). Dependence of the spectra upon pion charge, energy and angle, beam energy, system mass and associated multiplicity was investigated. Based on the isotropic angular distributions and the associated multiplicities for pion production, it apprears that subthreshold pions in the range of our experiment are produced predominantly from a source at rest in the center of mass and involving a large number of nucleons. The general character of the subthreshold pion spectra is comparable to previous results above threshold. However, the scaling of the subthreshold pion yield with system mass deviates from the dependence observed in light systems, to an extent which cannot be explained by a simple nucleon-nucleon model. We also found charge dependent structure in the pion spectra, which we analysed in the framework of both Coulomb distortion and clustering models. We conclude that while we did not clear evidence of collective effects in subthreshold pion production, it would be very worthwhile to conduct a systematic investigation of pion production for all charge states and over a range of angles, system masses and beam energies, below threshold.

  15. Effect of high energy electrons on H⁻ production and destruction in a high current DC negative ion source for cyclotron.

    PubMed

    Onai, M; Etoh, H; Aoki, Y; Shibata, T; Mattei, S; Fujita, S; Hatayama, A; Lettry, J

    2016-02-01

    Recently, a filament driven multi-cusp negative ion source has been developed for proton cyclotrons in medical applications. In this study, numerical modeling of the filament arc-discharge source plasma has been done with kinetic modeling of electrons in the ion source plasmas by the multi-cusp arc-discharge code and zero dimensional rate equations for hydrogen molecules and negative ions. In this paper, main focus is placed on the effects of the arc-discharge power on the electron energy distribution function and the resultant H(-) production. The modelling results reasonably explains the dependence of the H(-) extraction current on the arc-discharge power in the experiments. PMID:26932009

  16. Phosphatase PP4 Negatively Regulates Type I IFN Production and Antiviral Innate Immunity by Dephosphorylating and Deactivating TBK1.

    PubMed

    Zhan, Zhenzhen; Cao, Hao; Xie, Xuefeng; Yang, Linshan; Zhang, Peng; Chen, Yihan; Fan, Huimin; Liu, Zhongmin; Liu, Xingguang

    2015-10-15

    The effective recognition of viral infection and subsequent type I IFN production is essential for the host antiviral innate immune responses. The phosphorylation and activation of kinase TANK-binding kinase 1 (TBK1) plays crucial roles in the production of type I IFN mediated by TLR and retinoic acid-inducible gene I-like receptors. Type I IFN expression must be tightly regulated to prevent the development of immunopathological disorders. However, how the activated TBK1 is negatively regulated by phosphatases remains poorly understood. In this study, we identified a previously unknown role of protein phosphatase (PP)4 by acting as a TBK1 phosphatase. PP4 expression was upregulated in macrophages infected with RNA virus, vesicular stomatitis virus, and Sendai virus in vitro and in vivo. Knockdown of PP4C, the catalytic subunit of PP4, significantly increased type I IFN production in macrophages and dentritic cells triggered by TLR3/4 ligands, vesicular stomatitis virus, and Sendai virus, and thus inhibited virus replication. Similar results were also found in peritoneal macrophages with PP4C silencing in vivo and i.p. infection of RNA virus. Accordingly, ectopic expression of PP4C inhibited virus-induced type I IFN production and promoted virus replication. However, overexpression of a phosphatase-dead PP4C mutant abolished the inhibitory effects of wild-type PP4C on type I IFN production. Mechanistically, PP4 directly bound TBK1 upon virus infection, then dephosphorylated TBK1 at Ser(172) and inhibited TBK1 activation, and subsequently restrained IFN regulatory factor 3 activation, resulting in suppressed production of type I IFN and IFN-stimulated genes. Thus, serine/threonine phosphatase PP4 functions as a novel feedback negative regulator of RNA virus-triggered innate immunity. PMID:26363053

  17. CDCP1 Identifies a CD146 Negative Subset of Marrow Fibroblasts Involved with Cytokine Production

    PubMed Central

    Iwata, Mineo; Torok-Storb, Beverly; Wayner, Elizabeth A.; Carter, William G.

    2014-01-01

    In vitro expanded bone marrow stromal cells contain at least two populations of fibroblasts, a CD146/MCAM positive population, previously reported to be critical for establishing the stem cell niche and a CD146-negative population that expresses CUB domain-containing protein 1 (CDCP1)/CD318. Immunohistochemistry of marrow biopsies shows that clusters of CDCP1+ cells are present in discrete areas distinct from areas of fibroblasts expressing CD146. Using a stromal cell line, HS5, which approximates primary CDCP1+ stromal cells, we show that binding of an activating antibody against CDCP1 results in tyrosine-phosphorylation of CDCP1, paralleled by phosphorylation of Src Family Kinases (SFKs) Protein Kinase C delta (PKC-δ). When CDCP1 expression is knocked-down by siRNA, the expression and secretion of myelopoietic cytokines is increased. These data suggest CDCP1 expression can be used to identify a subset of marrow fibroblasts functionally distinct from CD146+ fibroblasts. Furthermore the CDCP1 protein may contribute to the defining function of these cells by regulating cytokine expression. PMID:25275584

  18. β-Lactamase Production in Key Gram-Negative Pathogen Isolates from the Arabian Peninsula

    PubMed Central

    Balkhy, Hanan H.; Walsh, Timothy R.; Paterson, David L.

    2013-01-01

    SUMMARY Infections due to Gram-negative bacilli (GNB) are a leading cause of morbidity and mortality worldwide. The extent of antibiotic resistance in GNB in countries of the Gulf Cooperation Council (GCC), namely, Saudi Arabia, United Arab Emirates, Kuwait, Qatar, Oman, and Bahrain, has not been previously reviewed. These countries share a high prevalence of extended-spectrum-β-lactamase (ESBL)- and carbapenemase-producing GNB, most of which are associated with nosocomial infections. Well-known and widespread β-lactamases genes (such as those for CTX-M-15, OXA-48, and NDM-1) have found their way into isolates from the GCC states. However, less common and unique enzymes have also been identified. These include PER-7, GES-11, and PME-1. Several potential risk factors unique to the GCC states may have contributed to the emergence and spread of β-lactamases, including the unnecessary use of antibiotics and the large population of migrant workers, particularly from the Indian subcontinent. It is clear that active surveillance of antimicrobial resistance in the GCC states is urgently needed to address regional interventions that can contain the antimicrobial resistance issue. PMID:23824364

  19. Protein export by a gram-negative bacterium: production of aerolysin by Aeromonas hydrophila.

    PubMed Central

    Howard, S P; Buckley, J T

    1985-01-01

    The synthesis and export of aerolysin, an extracellular protein toxin released by the gram-negative bacterium Aeromonas hydrophila, was studied by pulse-labeling with [35S]methionine. The toxin was synthesized as a higher-molecular-weight precursor. This was processed cotranslationally, resulting in the appearance within the cell of the mature protein, which was then exported to the supernatant. Precursor aerolysin accumulated in cells incubated in the presence of carbonyl cyanide m-chlorophenyl hydrazone, a substance which also inhibited the export of mature aerolysin from the cell. The entrapped mature toxin could not be shocked from the cells, although it could be digested by protease applied to shocked cells. The toxin was processed and translocated across the inner membrane of pleiotropic export mutants and accumulated in the periplasm. The results indicate that more than one step is required for the export of the protein and that aerolysin does not cross the inner and outer membranes simultaneously. Images PMID:3972770

  20. AIRS Products Confirm and Explain Recent Negative Trends of OLR as Observed by CERES

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Molnar, Gyula; Iredell, Lena

    2010-01-01

    Anomalies and trends of OLR serve as important indicators of climate change. Several satellite based instruments currently provide information related to OLR. CERES, on board the EOS Aqua and Terra satellites, contains broad band radiometers that measure total flux and short-wave flux, from which OLR is determined. AIRS is a high spectral resolution IR sounder on EOS Aqua that measures IR radiances covering most of the spectral interval 650/cm to 2670/cm. These observations enable the determination of detailed information about atmospheric temperature, moisture, and ozone profiles, as well as surface skin temperatures and cloud parameters. The AIRS OLR product is the total flux over the spectral interval 2/cm to 2750/cm computed for the surface and atmospheric state determined from AIRS observations. We compared spatial anomalies and trends of OLR, over the seven year period September 2002 through August 2009, as observed by CERES and computed using Version-5 AIRS products. These two sets of OLR anomalies and trends, obtained in very different ways, agree with each other almost perfectly in essentially every detail. This important finding shows that a very stable high spectral infra-red sounder such as AIRS corroborates the anomalies and trends of OLR obtained from CERES. More significantly, anomalies and trends of the individual geophysical parameters derived from AIRS explain the detailed causes of the anomalies and trends of CERES OLR. Both sets of results show that global mean OLR has been decreasing at a rate of 0.12 W/sq m/yr over the seven year time period under study. Both also confirm that the primary cause of this is due to changes in the tropics, in which OLR has been decreasing at a rate of 0.27 W/sq m/yr. AIRS products show that the decrease of tropical OLR is a result of increasing tropical atmospheric water vapor and cloud cover over that time period studied, which in turn is responding to a very strong La Nina; a event starting in late 2007

  1. Cross-Section Parameterizations for Pion and Nucleon Production From Negative Pion-Proton Collisions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Blattnig, Steve R.; Norman, Ryan; Tripathi, R. K.

    2002-01-01

    Ranft has provided parameterizations of Lorentz invariant differential cross sections for pion and nucleon production in pion-proton collisions that are compared to some recent data. The Ranft parameterizations are then numerically integrated to form spectral and total cross sections. These numerical integrations are further parameterized to provide formula for spectral and total cross sections suitable for use in radiation transport codes. The reactions analyzed are for charged pions in the initial state and both charged and neutral pions in the final state.

  2. A CW radiofrequency ion source for production of negative hydrogen ion beams for cyclotrons

    SciTech Connect

    Kalvas, T.; Tarvainen, O.; Komppula, J.; Koivisto, H.; Tuunanen, J.; Potkins, D.; Stewart, T.; Dehnel, M. P.

    2015-04-08

    A CW 13.56 MHz radiofrequency-driven ion source RADIS for production of H{sup −} and D{sup −} beams is under development for replacing the filament-driven ion source of the MCC30/15 cyclotron. The RF ion source has a 16-pole multicusp plasma chamber, an electromagnet-based magnetic filter and an external planar spiral RF antenna behind an AlN window. The extraction is a 5-electrode system with an adjustable puller electrode voltage for optimizing the beam formation, a water-cooled electron dump electrode and an accelerating einzel lens. At 2650 W of RF power, the source produces 1 mA of H{sup −} (2.6 mA/cm{sup 2}), which is the intensity needed at injection for production of 200 µA H{sup +} with the filament-driven ion source. A simple pepperpot device has been developed for characterizing the beam emittance. Plans for improving the power efficiency with the use of a new permanent magnet front plate is discussed.

  3. Evaluating the degradation, sorption, and negative mass balances of pharmaceuticals and personal care products during wastewater treatment.

    PubMed

    Blair, Benjamin; Nikolaus, Adam; Hedman, Curtis; Klaper, Rebecca; Grundl, Timothy

    2015-09-01

    Conventional activated sludge (CAS) wastewater treatment processes are insufficient at removing many pharmaceutical and personal care products (PPCPs) from wastewater. In addition, negative mass balances, where the effluent concentration is greater than the influent concentration, have been observed in wastewater treatment studies and a further understanding of these results is needed. In this study, the fate and occurrence of 57 PPCPs and hormones were evaluated in an activated sludge process and the mass balances were determined. The goal of the project was to understand the PPCPs biological degradation and the extent of sorption to solids. The samples containing in situ PPCPs (i.e. samples were not spiked with additional PPCPs) were evaluated. Forty-eight of the PPCPs were detected in the soluble form and 29 were detected sorbed to solids. Two notable results were found. First, the results of this study indicate a subset of the highly biodegradable PPCPs stop being degraded at low, yet notable, concentrations. Second, the results revealed that negative mass balances were present for a subset of the PPCPs when evaluating both the soluble and sorbed concentration, for example carbamazepine and ofloxacin. Desorption from solids was not found to attribute to negative mass balances. Overall, the results from this study provide new insights into the fate of PPCPs during CAS wastewater treatment by evaluating the degradation kinetics and sorption and the results may explain the consistent levels of highly degradable PPCPs being emitted from WWTPs worldwide. PMID:25985097

  4. Ozone production of hollow-needle-to-mesh negative corona discharge enhanced by dielectric tube on the needle electrode

    NASA Astrophysics Data System (ADS)

    Pekárek, Stanislav

    2014-12-01

    For the hollow-needle-to-mesh negative corona discharge in air, we studied the effect of placing the dielectric tube on the needle electrode and the effect of various positions of the end of this tube with respect to the tip of the needle electrode on the concentration of ozone produced by the discharge, the ozone production yield and the discharge V-A characteristics. We found that the placement of the dielectric tube on the needle electrode with a suitable position of this tube end with respect to the tip of the needle electrode for a particular discharge power led to a more than fourfold increase in the concentration of ozone produced by the discharge and also, for a constant airflow, the ozone production yield.

  5. Role of positive ions on the surface production of negative ions in a fusion plasma reactor type negative ion source--Insights from a three dimensional particle-in-cell Monte Carlo collisions model

    NASA Astrophysics Data System (ADS)

    Fubiani, G.; Boeuf, J. P.

    2013-11-01

    Results from a 3D self-consistent Particle-In-Cell Monte Carlo Collisions (PIC MCC) model of a high power fusion-type negative ion source are presented for the first time. The model is used to calculate the plasma characteristics of the ITER prototype BATMAN ion source developed in Garching. Special emphasis is put on the production of negative ions on the plasma grid surface. The question of the relative roles of the impact of neutral hydrogen atoms and positive ions on the cesiated grid surface has attracted much attention recently and the 3D PIC MCC model is used to address this question. The results show that the production of negative ions by positive ion impact on the plasma grid is small with respect to the production by atomic hydrogen or deuterium bombardment (less than 10%).

  6. Role of positive ions on the surface production of negative ions in a fusion plasma reactor type negative ion source—Insights from a three dimensional particle-in-cell Monte Carlo collisions model

    SciTech Connect

    Fubiani, G.; Boeuf, J. P.

    2013-11-15

    Results from a 3D self-consistent Particle-In-Cell Monte Carlo Collisions (PIC MCC) model of a high power fusion-type negative ion source are presented for the first time. The model is used to calculate the plasma characteristics of the ITER prototype BATMAN ion source developed in Garching. Special emphasis is put on the production of negative ions on the plasma grid surface. The question of the relative roles of the impact of neutral hydrogen atoms and positive ions on the cesiated grid surface has attracted much attention recently and the 3D PIC MCC model is used to address this question. The results show that the production of negative ions by positive ion impact on the plasma grid is small with respect to the production by atomic hydrogen or deuterium bombardment (less than 10%)

  7. Plant response to environmental conditions: assessing potential production, water demand, and negative effects of water deficit

    PubMed Central

    Tardieu, François

    2013-01-01

    This paper reviews methods for analyzing plant performance and its genetic variability under a range of environmental conditions. Biomass accumulation is linked every day to available light in the photosynthetically active radiation (PAR) domain, multiplied by the proportion of light intercepted by plants and by the radiation use efficiency. Total biomass is cumulated over the duration of the considered phase (e.g., plant cycle or vegetative phase). These durations are essentially constant for a given genotype provided that time is corrected for temperature (thermal time). Several ways of expressing thermal time are reviewed. Two alternative equations are presented, based either on the effect of transpiration, or on yield components. Their comparative interests and drawbacks are discussed. The genetic variability of each term of considered equations affects yield under water deficit, via mechanisms at different scales of plant organization and time. The effect of any physiological mechanism on yield of stressed plants acts via one of these terms, although the link is not always straightforward. Finally, I propose practical ways to compare the productivity of genotypes in field environments, and a “minimum dataset” of environmental data and traits that should be recorded for that. PMID:23423357

  8. Production of Stabilized Virulence Factor-Negative Variants by Group A Streptococci during Stationary Phase

    PubMed Central

    Leonard, B. A. B.; Woischnik, M.; Podbielski, A.

    1998-01-01

    Many of the virulence factors associated with fulminant group A streptococci (GAS) infection are expressed under in vitro exponential growth conditions. However, the survival of GAS in tissue and intracellularly, as well as colonization of asymptomatic carriers, has been reported for GAS. The bacteria associated with these niches may encounter high-density, low-nutrient-flowthrough conditions that may more closely mimic in vitro stationary-phase conditions than exponential growth. Therefore, the behavior of GAS in stationary-phase culture was examined. We observed that after 24 h in stationary phase, GAS serotypes M49 and M2 developed a unstable colony dimorphism of typical large and atypical small colonies. Between days 4 and 5, we isolated stabilized atypical small colonies which remained stable for up to nine passages (approximately 200 generations) on fresh medium before fully reverting to the large-colony phenotype. Upon analysis, the small colonies showed no difference in cell number per colony, growth rate, survival in prolonged stationary-phase culture, or antibiotic sensitivity. However, the small colonies showed decreased transcription of hyaluronic acid capsule, the global positive virulence factor regulator gene mga, the mga-regulated emm mRNA (M-protein structural gene), and speB (cysteine protease). Accordingly, the small colonies were completely sensitive in a traditional phagocytosis assay. The production of virulence factors and phagocytosis resistance of the small-colony isolates was recovered when, after several passages on fresh medium, the colony morphology began to revert. PMID:9673270

  9. Production of stabilized virulence factor-negative variants by group A streptococci during stationary phase.

    PubMed

    Leonard, B A; Woischnik, M; Podbielski, A

    1998-08-01

    Many of the virulence factors associated with fulminant group A streptococci (GAS) infection are expressed under in vitro exponential growth conditions. However, the survival of GAS in tissue and intracellularly, as well as colonization of asymptomatic carriers, has been reported for GAS. The bacteria associated with these niches may encounter high-density, low-nutrient-flowthrough conditions that may more closely mimic in vitro stationary-phase conditions than exponential growth. Therefore, the behavior of GAS in stationary-phase culture was examined. We observed that after 24 h in stationary phase, GAS serotypes M49 and M2 developed a unstable colony dimorphism of typical large and atypical small colonies. Between days 4 and 5, we isolated stabilized atypical small colonies which remained stable for up to nine passages (approximately 200 generations) on fresh medium before fully reverting to the large-colony phenotype. Upon analysis, the small colonies showed no difference in cell number per colony, growth rate, survival in prolonged stationary-phase culture, or antibiotic sensitivity. However, the small colonies showed decreased transcription of hyaluronic acid capsule, the global positive virulence factor regulator gene mga, the mga-regulated emm mRNA (M-protein structural gene), and speB (cysteine protease). Accordingly, the small colonies were completely sensitive in a traditional phagocytosis assay. The production of virulence factors and phagocytosis resistance of the small-colony isolates was recovered when, after several passages on fresh medium, the colony morphology began to revert. PMID:9673270

  10. A negative regulator mediates quorum-sensing control of exopolysaccharide production in Pantoea stewartii subsp. stewartii.

    PubMed

    von Bodman, S B; Majerczak, D R; Coplin, D L

    1998-06-23

    Classical quorum-sensing (autoinduction) regulation, as exemplified by the lux system of Vibrio fischeri, requires N-acyl homoserine lactone (AHL) signals to stimulate cognate transcriptional activators for the cell density-dependent expression of specific target gene systems. For Pantoea stewartii subsp. stewartii, a bacterial pathogen of sweet corn and maize, the extracellular polysaccharide (EPS) stewartan is a major virulence factor, and its production is controlled by quorum sensing in a population density-dependent manner. Two genes, esaI and esaR, encode essential regulatory proteins for quorum sensing. EsaI is the AHL signal synthase, and EsaR is the cognate gene regulator. esaI, DeltaesaR, and DeltaesaI-esaR mutations were constructed to establish the regulatory role of EsaR. We report here that strains containing an esaR mutation produce high levels of EPS independently of cell density and in the absence of the AHL signal. Our data indicate that quorum-sensing regulation in P. s. subsp. stewartii, in contrast to most other described systems, uses EsaR to repress EPS synthesis at low cell density, and that derepression requires micromolar amounts of AHL. In addition, derepressed esaR strains, which synthesize EPS constitutively at low cell densities, were significantly less virulent than the wild-type parent. This finding suggests that quorum sensing in P. s. subsp. stewartii may be a mechanism to delay the expression of EPS during the early stages of infection so that it does not interfere with other mechanisms of pathogenesis. PMID:9636211

  11. Compression effects in inductively coupled, high-power radio-frequency discharges for negative hydrogen ion production

    NASA Astrophysics Data System (ADS)

    Wilhelm, Rolf

    2003-02-01

    In the paper we present a simplified model description of inductively coupled plasma discharges operating at a rather high radio-frequency (rf) power. In this case the induced high plasma currents can cause periodic compressions over a substantial radial distance. Such conditions are obviously given in rf driven 1 MHz/150 kW plasma sources developed at the Institute for Plasma Physics Garching for negative (hydrogen) ion production in future neutral beam injection (NBI) systems for nuclear fusion research, such as the 1 MeV/50 MW NBI system for the International Thermonuclear Experimental Reactor [T. Inoue, R. Hemsworth, V. Kulygin, and Y. Okumura, Fusion Eng. Design 55, 291 (2001)]. The given model describes quite well the compression and other features of the discharge. The results include the Ohmic power input (i.e., electron heating), the resulting density build-up, and—as a new feature—periodical plasma compressions, leading to a direct energy input also into the plasma ions. The model also explains the strange effect of small argon admixtures, which improve the negative ion yield in rf sources by a factor of up to 2-3 (but which have no effect in conventional dc arc sources). With the calculated dependencies from external parameters (e.g., rf-power and frequency, gas pressure, ion mass or the specific geometry), the modeling may help for the further optimization of the rf source.

  12. Welfare effects of reduced milk production associated with Johne's disease on Johne's-positive versus Johne's-negative dairy operations.

    PubMed

    Losinger, Willard C

    2006-08-01

    An examination of the economic impacts of reduced milk production associated with Johne's disease on Johne's-positive and Johne's-negative dairy operations indicated that, if Johne's disease had not existed in US dairy cows in 1996, then the economic surplus of Johne's-negative operations would have been $600 million+/-$530 million lower, while the economic surplus of Johne's-positive operations would have been higher by $28 million+/-$79 million, which was not significantly different from zero. The data available for projecting changes in surplus were not sufficiently precise to allow an exact statement on whether Johne's-positive operations would have been better or worse off economically, in terms of the value received for producing more milk if they had not been affected by Johne's disease. The changes in producer surplus, based upon eliminating specific epidemiological risk factors for Johne's disease, were disaggregated between Johne's-positive dairy operations exposed to the risk factor and all other US dairy operations. Eliminating the risk factor of having any cows not born on the operation would have had a significant positive effect on the economic surplus of Johne's-positive operations that had any cows not born on the operation. PMID:16827950

  13. CysB Negatively Affects the Transcription of pqsR and Pseudomonas Quinolone Signal Production in Pseudomonas aeruginosa

    PubMed Central

    Farrow, John M.; Hudson, L. Lynn; Wells, Greg; Coleman, James P.

    2015-01-01

    ABSTRACT Pseudomonas aeruginosa is a Gram-negative bacterium that is ubiquitous in the environment, and it is an opportunistic pathogen that can infect a variety of hosts, including humans. During the process of infection, P. aeruginosa coordinates the expression of numerous virulence factors through the production of multiple cell-to-cell signaling molecules. The production of these signaling molecules is linked through a regulatory network, with the signal N-(3-oxododecanoyl) homoserine lactone and its receptor LasR controlling the induction of a second acyl-homoserine lactone signal and the Pseudomonas quinolone signal (PQS). LasR-mediated control of PQS occurs partly by activating the transcription of pqsR, a gene that encodes the PQS receptor and is necessary for PQS production. We show that LasR interacts with a single binding site in the pqsR promoter region and that it does not influence the transcription of the divergently transcribed gene, nadA. Using DNA affinity chromatography, we identified additional proteins that interact with the pqsR-nadA intergenic region. These include the H-NS family members MvaT and MvaU, and CysB, a transcriptional regulator that controls sulfur uptake and cysteine biosynthesis. We show that CysB interacts with the pqsR promoter and that CysB represses pqsR transcription and PQS production. Additionally, we provide evidence that CysB can interfere with the activation of pqsR transcription by LasR. However, as seen with other CysB-regulated genes, pqsR expression was not differentially regulated in response to cysteine levels. These findings demonstrate a novel role for CysB in influencing cell-to-cell signal production by P. aeruginosa. IMPORTANCE The production of PQS and other 4-hydroxy-2-alkylquinolone (HAQs) compounds is a key component of the P. aeruginosa cell-to-cell signaling network, impacts multiple physiological functions, and is required for virulence. PqsR directly regulates the genes necessary for HAQ production

  14. Negative Role of RIG-I Serine 8 Phosphorylation in the Regulatin of Interferon-beta Production

    SciTech Connect

    E Nistal-Villan; M Gack; G Martinez-Delgado; N Maharaj; K Inn; H Yang; R Wang; A Aggarwal; J Jung; A Garcia-Sastre

    2011-12-31

    RIG-I (retinoic acid-inducible gene I) and TRIM25 (tripartite motif protein 25) have emerged as key regulatory factors to induce interferon (IFN)-mediated innate immune responses to limit viral replication. Upon recognition of viral RNA, TRIM25 E3 ligase binds the first caspase recruitment domain (CARD) of RIG-I and subsequently induces lysine 172 ubiquitination of the second CARD of RIG-I, which is essential for the interaction with downstream MAVS/IPS-1/CARDIF/VISA and, thereby, IFN-beta mRNA production. Although ubiquitination has emerged as a major factor involved in RIG-I activation, the potential contribution of other post-translational modifications, such as phosphorylation, to the regulation of RIG-I activity has not been addressed. Here, we report the identification of serine 8 phosphorylation at the first CARD of RIG-I as a negative regulatory mechanism of RIG-I-mediated IFN-beta production. Immunoblot analysis with a phosphospecific antibody showed that RIG-I serine 8 phosphorylation steady-state levels were decreased upon stimulation of cells with IFN-beta or virus infection. Substitution of serine 8 in the CARD RIG-I functional domain with phosphomimetic aspartate or glutamate results in decreased TRIM25 binding, RIG-I ubiquitination, MAVS binding, and downstream signaling. Finally, sequence comparison reveals that only primate species carry serine 8, whereas other animal species carry an asparagine, indicating that serine 8 phosphorylation may represent a primate-specific regulation of RIG-I activation. Collectively, these data suggest that the phosphorylation of RIG-I serine 8 operates as a negative switch of RIG-I activation by suppressing TRIM25 interaction, further underscoring the importance of RIG-I and TRIM25 connection in type I IFN signal transduction.

  15. AIRS Water Vapor and Cloud Products Validate and Explain Recent Negative Global and Tropical OLR Trends Observed by CERES

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Molnar, Gyula; Iredell, Lena

    2010-01-01

    This paper compares spatial and temporal anomalies and trends of OLR as observed by CERES and computed based on AIRS retrieved surface and atmospheric geophysical parameters over the time period September 2002 February 2010. This time period is marked by a substantial decreasing OLR trend on the order of -0.1 W/m2/yr averaged over the globe. There are very large spatial variations of these trends however, with local values ranging from -2.6 W/m2/yr to +3.0 W/m2/yr in the tropics. The spatial patterns of the AIRS and CERES trends are in essentially perfect agreement with each other, as are the anomaly time series averaged over different spatial regions. This essentially perfect agreement of OLR anomalies and trends derived from observations by two different instruments, in totally independent and different manners, implies that both sets of results must be highly accurate. The agreement of anomalies and trends of OLR as observed by CERES and computed from AIRS derived products also indirectly validates the anomalies and trends of the AIRS derived products as well. We used the anomalies and trends of AIRS derived water vapor and cloud products to explain why global OLR has had a large negative trend over the time period September 2002 through February 2010. Tropical OLR began to decrease significantly at the onset of a strong La Nina in mid-2007. AIRS products show that cloudiness and mid-tropospheric water vapor began to increase in the region 5degN - 20degS latitude extending eastward from 150degW - 30 E longitude at that time, with a corresponding very large drop in OLR in this region. Late 2009 is characterized by a strong El-Nino, with a corresponding change in sign of observed anomalies of mid-tropospheric water vapor, cloud cover, and OLR in this region, as we] l as that of OLR anomalies in the tropics and globally. Monthly mean anomalies of OLR, water vapor and cloud cover over this region are all shown to be highly correlated in time with those of an El Nino

  16. Negative Oxygen Ions Production by Superamphiphobic and Antibacterial TiO2/Cu2O Composite Film Anchored on Wooden Substrates

    NASA Astrophysics Data System (ADS)

    Gao, Likun; Qiu, Zhe; Gan, Wentao; Zhan, Xianxu; Li, Jian; Qiang, Tiangang

    2016-05-01

    According to statistics, early in the 20th century, the proportion of positive and negative air ions on the earth is 1 : 1.2. However, after more than one century, the equilibrium state of the proportion had an obvious change, which the proportion of positive and negative air ions became 1.2 : 1, leading to a surrounding of positive air ions in human living environment. Therefore, it is urgent to adopt effective methods to improve the proportion of negative oxygen ions, which are known as “air vitamin”. In this study, negative oxygen ions production by the TiO2/Cu2O-treated wood under UV irradiation was first reported. Anatase TiO2 particles with Cu2O particles were doped on wooden substrates through a two-step method and further modification is employed to create remarkable superamphiphobic surface. The effect of Cu2O particles dopant on the negative oxygen ions production of the TiO2-treated wood was investigated. The results showed that the production of negative oxygen ions was drastically improved by doping with Cu2O particles under UV irradiation. The wood modified with TiO2/Cu2O composite film after hydrophobization is imparted with superamphiphobicity, antibacterial actions against Escherichia coli, and negative oxygen ions production under UV irradiation.

  17. Negative Oxygen Ions Production by Superamphiphobic and Antibacterial TiO2/Cu2O Composite Film Anchored on Wooden Substrates.

    PubMed

    Gao, Likun; Qiu, Zhe; Gan, Wentao; Zhan, Xianxu; Li, Jian; Qiang, Tiangang

    2016-01-01

    According to statistics, early in the 20th century, the proportion of positive and negative air ions on the earth is 1 : 1.2. However, after more than one century, the equilibrium state of the proportion had an obvious change, which the proportion of positive and negative air ions became 1.2 : 1, leading to a surrounding of positive air ions in human living environment. Therefore, it is urgent to adopt effective methods to improve the proportion of negative oxygen ions, which are known as "air vitamin". In this study, negative oxygen ions production by the TiO2/Cu2O-treated wood under UV irradiation was first reported. Anatase TiO2 particles with Cu2O particles were doped on wooden substrates through a two-step method and further modification is employed to create remarkable superamphiphobic surface. The effect of Cu2O particles dopant on the negative oxygen ions production of the TiO2-treated wood was investigated. The results showed that the production of negative oxygen ions was drastically improved by doping with Cu2O particles under UV irradiation. The wood modified with TiO2/Cu2O composite film after hydrophobization is imparted with superamphiphobicity, antibacterial actions against Escherichia coli, and negative oxygen ions production under UV irradiation. PMID:27229763

  18. Negative Oxygen Ions Production by Superamphiphobic and Antibacterial TiO2/Cu2O Composite Film Anchored on Wooden Substrates

    PubMed Central

    Gao, Likun; Qiu, Zhe; Gan, Wentao; Zhan, Xianxu; Li, Jian; Qiang, Tiangang

    2016-01-01

    According to statistics, early in the 20th century, the proportion of positive and negative air ions on the earth is 1 : 1.2. However, after more than one century, the equilibrium state of the proportion had an obvious change, which the proportion of positive and negative air ions became 1.2 : 1, leading to a surrounding of positive air ions in human living environment. Therefore, it is urgent to adopt effective methods to improve the proportion of negative oxygen ions, which are known as “air vitamin”. In this study, negative oxygen ions production by the TiO2/Cu2O-treated wood under UV irradiation was first reported. Anatase TiO2 particles with Cu2O particles were doped on wooden substrates through a two-step method and further modification is employed to create remarkable superamphiphobic surface. The effect of Cu2O particles dopant on the negative oxygen ions production of the TiO2-treated wood was investigated. The results showed that the production of negative oxygen ions was drastically improved by doping with Cu2O particles under UV irradiation. The wood modified with TiO2/Cu2O composite film after hydrophobization is imparted with superamphiphobicity, antibacterial actions against Escherichia coli, and negative oxygen ions production under UV irradiation. PMID:27229763

  19. Production of N-acylhomoserine lactone signal molecules by gram-negative soil-borne and plant-associated bacteria.

    PubMed

    Veselova, M; Kholmeckaya, M; Klein, S; Voronina, E; Lipasova, V; Metlitskaya, A; Mayatskaya, A; Lobanok, E; Khmel, I; Chernin, L

    2003-01-01

    Quorum-sensing control mediated by N-acylhomoserine lactone (AHL) signal molecules has been established as a key feature in the regulation of various metabolic traits in many bacteria. Approximately 300 strains representing 6 genera and 18 species of soil-borne and plant-associated Gram-negative bacteria isolated in various regions of the former USSR using two reporter systems were screened for AHL production. The production was observed in 17.5% of the screened bacterial strains. Positive response was detected in all of the 14 tested strains of Erwinia herbicola, in 41 of the 239 strains of Pseudomonas species; in all 5 strains of Xanthomonas ampelina, X. campestris pv. malvacearum, pv. translucens, pv. vesicatoria and in one strain of Pantoea stewartii. AHL assay of 41 strains of X. maltophilia (syn. Stenotrophomonas maltophilia) isolated from soils with Chromobacterium violaceum reporter has revealed no strains synthesizing these signal molecules; 26 strains analyzed with Agrobacterium tumefaciens reporter showed the same result. PMID:15058194

  20. An inhibitor persistently decreased enteric methane emission from dairy cows with no negative effect on milk production

    PubMed Central

    Hristov, Alexander N.; Oh, Joonpyo; Giallongo, Fabio; Frederick, Tyler W.; Harper, Michael T.; Weeks, Holley L.; Branco, Antonio F.; Moate, Peter J.; Deighton, Matthew H.; Williams, S. Richard O.; Kindermann, Maik; Duval, Stephane

    2015-01-01

    A quarter of all anthropogenic methane emissions in the United States are from enteric fermentation, primarily from ruminant livestock. This study was undertaken to test the effect of a methane inhibitor, 3-nitrooxypropanol (3NOP), on enteric methane emission in lactating Holstein cows. An experiment was conducted using 48 cows in a randomized block design with a 2-wk covariate period and a 12-wk data collection period. Feed intake, milk production, and fiber digestibility were not affected by the inhibitor. Milk protein and lactose yields were increased by 3NOP. Rumen methane emission was linearly decreased by 3NOP, averaging about 30% lower than the control. Methane emission per unit of feed dry matter intake or per unit of energy-corrected milk were also about 30% less for the 3NOP-treated cows. On average, the body weight gain of 3NOP-treated cows was 80% greater than control cows during the 12-wk experiment. The experiment demonstrated that the methane inhibitor 3NOP, applied at 40 to 80 mg/kg feed dry matter, decreased methane emissions from high-producing dairy cows by 30% and increased body weight gain without negatively affecting feed intake or milk production and composition. The inhibitory effect persisted over 12 wk of treatment, thus offering an effective methane mitigation practice for the livestock industries. PMID:26229078

  1. An inhibitor persistently decreased enteric methane emission from dairy cows with no negative effect on milk production.

    PubMed

    Hristov, Alexander N; Oh, Joonpyo; Giallongo, Fabio; Frederick, Tyler W; Harper, Michael T; Weeks, Holley L; Branco, Antonio F; Moate, Peter J; Deighton, Matthew H; Williams, S Richard O; Kindermann, Maik; Duval, Stephane

    2015-08-25

    A quarter of all anthropogenic methane emissions in the United States are from enteric fermentation, primarily from ruminant livestock. This study was undertaken to test the effect of a methane inhibitor, 3-nitrooxypropanol (3NOP), on enteric methane emission in lactating Holstein cows. An experiment was conducted using 48 cows in a randomized block design with a 2-wk covariate period and a 12-wk data collection period. Feed intake, milk production, and fiber digestibility were not affected by the inhibitor. Milk protein and lactose yields were increased by 3NOP. Rumen methane emission was linearly decreased by 3NOP, averaging about 30% lower than the control. Methane emission per unit of feed dry matter intake or per unit of energy-corrected milk were also about 30% less for the 3NOP-treated cows. On average, the body weight gain of 3NOP-treated cows was 80% greater than control cows during the 12-wk experiment. The experiment demonstrated that the methane inhibitor 3NOP, applied at 40 to 80 mg/kg feed dry matter, decreased methane emissions from high-producing dairy cows by 30% and increased body weight gain without negatively affecting feed intake or milk production and composition. The inhibitory effect persisted over 12 wk of treatment, thus offering an effective methane mitigation practice for the livestock industries. PMID:26229078

  2. MicroRNA-124 negatively regulates LPS-induced TNF-α production in mouse macrophages by decreasing protein stability

    PubMed Central

    Sun, Yang; Qin, Zhen; Li, Qi; Wan, Jing-jing; Cheng, Ming-he; Wang, Peng-yuan; Su, Ding-feng; Yu, Jian-guang; Liu, Xia

    2016-01-01

    Aim: MicroRNAs play pivotal roles in regulation of both innate and adaptive immune responses. In the present study, we investigated the effects of microRNA-124 (miR-124) on production of the pro-inflammatory cytokine TNF-α in lipopolysaccharide (LPS)-treated mouse macrophages. Methods: Mouse macrophage cell line RAW264.7 was stimulated with LPS (100 ng/mL). The levels of miR-124 and TNF-α mRNA were evaluated using q-PCR. ELISA and Western blotting were used to detect TNF-α protein level in cell supernatants and cells, respectively. 3′-UTR luciferase reporter assays were used to analyze the targets of miR-124. For in vivo experiments, mice were injected with LPS (30 mg/kg, ip). Results: LPS stimulation significantly increased the mRNA level of miR-124 in RAW264.7 macrophages in vitro and mice in vivo. In RAW264.7 macrophages, knockdown of miR-124 with miR-124 inhibitor dose-dependently increased LPS-stimulated production of TNF-α protein and prolonged the half-life of TNF-α protein, but did not change TNF-α mRNA levels, whereas overexpression of miR-124 with miR-124 mimic produced the opposite effects. Furthermore, miR-124 was found to directly target two components of deubiquitinating enzymes: ubiquitin-specific proteases (USP) 2 and 14. Knockdown of USP2 or USP14 accelerated protein degradation of TNF-α, and abolished the effect of miR-124 on TNF-α protein stability. Conclusion: miR-124, targeting USP2 and USP14, negatively regulates LPS-induced TNF-α production in mouse macrophages, suggesting miR-124 as a new therapeutic target in inflammation-related diseases. PMID:27063215

  3. Causal production of the electromagnetic energy flux and role of the negative energies in the Blandford-Znajek process

    NASA Astrophysics Data System (ADS)

    Toma, Kenji; Takahara, Fumio

    2016-06-01

    The Blandford-Znajek process, the steady electromagnetic energy extraction from a rotating black hole (BH), is widely believed to work for driving relativistic jets in active galactic nuclei, gamma-ray bursts, and Galactic microquasars, although it is still under debate how the Poynting flux is causally produced and how the rotational energy of the BH is reduced. We generically discuss the Kerr BH magnetosphere filled with a collisionless plasma screening the electric field along the magnetic field, extending the arguments of Komissarov [S. S. Komissarov, Mon. Not. R. Astron. Soc., 50, 427 (2004)] and our previous [K. Toma and F. Takahara, Mon. Not. R. Astron. Soc., 442, 2855 (2014)] paper, and propose a new picture for resolving the issues. For the magnetic field lines threading the equatorial plane in the ergosphere, we find that the inflow of particles with negative energy as measured in the coordinate basis is generated near that plane as a feedback from the Poynting flux production, which appears to be a similar process to the mechanical Penrose process. For the field lines threading the event horizon, we first show that the concept of the steady inflow of negative electromagnetic energy is not physically essential, partly because the sign of the electromagnetic energy density depends on the coordinates. Then we build an analytical toy model of a time-dependent process in both the Boyer-Lindquist and Kerr-Schild coordinate systems, in which the force-free plasma injected continuously fills a vacuum, and suggest that the structure of the steady outward Poynting flux is causally constructed by the displacement current and the cross-field current at the ingoing boundary between the plasma and the vacuum. In the steady state, the Poynting flux is maintained without any electromagnetic source.

  4. The retinoblastoma gene product RB stimulates Sp1-mediated transcription by liberating Sp1 from a negative regulator.

    PubMed Central

    Chen, L I; Nishinaka, T; Kwan, K; Kitabayashi, I; Yokoyama, K; Fu, Y H; Grünwald, S; Chiu, R

    1994-01-01

    Studies have demonstrated that the retinoblastoma susceptibility gene product, RB, can either positively or negatively regulate expression of several genes through cis-acting elements in a cell-type-dependent manner. The nucleotide sequence of the retinoblastoma control element (RCE) motif, GCCACC or CCACCC, and the Sp1 consensus binding sequence, CCGCCC, can confer equal responsiveness to RB. Here, we report that RB activates transcription of the c-jun gene through the Sp1-binding site within the c-jun promoter. Preincubation of crude nuclear extracts with monoclonal antibodies to RB results in reduction of Sp1 complexes in a mobility shift assay, while addition of recombinant RB in mobility shift assay mixtures with CCL64 cell extracts leads to an enhancement of DNA-binding activity of SP1. These results suggest that RB is directly or indirectly involved in Sp1-DNA binding activity. A mechanism by which RB regulates transactivation is indicated by our detection of a heat-labile and protease-sensitive Sp1 negative regulator(s) (Sp1-I) that specifically inhibits Sp1 binding to a c-jun Sp1 site. This inhibition is reversed by addition of recombinant RB proteins, suggesting that RB stimulates Sp1-mediated transactivation by liberating Sp1 from Sp1-I. Additional evidence for Sp1-I involvement in Sp1-mediated transactivation was demonstrated by cotransfection of RB, GAL4-Sp1, and a GAL4-responsive template into CV-1 cells. Finally, we have identified Sp1-I, a approximately 20-kDa protein(s) that inhibits the Sp1 complexes from binding to DNA and that is also an RB-associated protein. These findings provide evidence for a functional link between two distinct classes of oncoproteins, RB and c-Jun, that are involved in the control of cell growth, and also define a novel mechanism for the regulation of c-jun expression. Images PMID:8007947

  5. AIRS Water Vapor and Cloud Products Validate and Explain Recent Negative Global and Tropical OLR Trends Observed by CERES

    NASA Astrophysics Data System (ADS)

    Susskind, J.; Molnar, G. I.; Iredell, L. F.; Sounder Research Team

    2010-12-01

    Joel Susskind, Gyula Molnar, and Lena Iredell NASA GSFC Sounder Research Team Abstract This paper compares spatial and temporal anomalies and trends of OLR as observed by CERES and computed based on AIRS retrieved surface and atmospheric geophysical parameters over the time period September 2002 - February 2010. This time period is marked by a substantial decreasing OLR trend on the order of -0.1 W/m2/yr averaged over the globe. There are very large spatial variations of these trends however, with local values ranging from -2.6 W/m2/yr to +3.0 W/m2/yr in the tropics. The spatial patterns of the AIRS and CERES trends are in essentially perfect agreement with each other, as are the anomaly time series averaged over different spatial regions. This essentially perfect agreement of OLR anomalies and trends derived from observations by two different instruments, in totally independent and different manners, implies that both sets of results must be highly accurate. The agreement of anomalies and trends of OLR as observed by CERES and computed from AIRS derived products also indirectly validates the anomalies and trends of the AIRS derived products as well. We used the anomalies and trends of AIRS derived water vapor and cloud products to explain why global OLR has had a large negative trend over the time period September 2002 through February 2010. Tropical OLR began to decrease significantly at the onset of a strong La Niña in mid-2007. AIRS products show that cloudiness and mid-tropospheric water vapor began to increase in the region 5°N - 20°S latitude extending eastward from 150°W - 30°E longitude at that time, with a corresponding very large drop in OLR in this region. Late 2009 is characterized by a strong El-Niño, with a corresponding change in sign of observed anomalies of mid-tropospheric water vapor, cloud cover, and OLR in this region, as well as that of OLR anomalies in the tropics and globally. Monthly mean anomalies of OLR, water vapor and cloud cover

  6. Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production

    PubMed Central

    Rau, Greg H.; Carroll, Susan A.; Bourcier, William L.; Singleton, Michael J.; Smith, Megan M.; Aines, Roger D.

    2013-01-01

    We experimentally demonstrate the direct coupling of silicate mineral dissolution with saline water electrolysis and H2 production to effect significant air CO2 absorption, chemical conversion, and storage in solution. In particular, we observed as much as a 105-fold increase in OH− concentration (pH increase of up to 5.3 units) relative to experimental controls following the electrolysis of 0.25 M Na2SO4 solutions when the anode was encased in powdered silicate mineral, either wollastonite or an ultramafic mineral. After electrolysis, full equilibration of the alkalized solution with air led to a significant pH reduction and as much as a 45-fold increase in dissolved inorganic carbon concentration. This demonstrated significant spontaneous air CO2 capture, chemical conversion, and storage as a bicarbonate, predominantly as NaHCO3. The excess OH− initially formed in these experiments apparently resulted via neutralization of the anolyte acid, H2SO4, by reaction with the base mineral silicate at the anode, producing mineral sulfate and silica. This allowed the NaOH, normally generated at the cathode, to go unneutralized and to accumulate in the bulk electrolyte, ultimately reacting with atmospheric CO2 to form dissolved bicarbonate. Using nongrid or nonpeak renewable electricity, optimized systems at large scale might allow relatively high-capacity, energy-efficient (<300 kJ/mol of CO2 captured), and inexpensive (<$100 per tonne of CO2 mitigated) removal of excess air CO2 with production of carbon-negative H2. Furthermore, when added to the ocean, the produced hydroxide and/or (bi)carbonate could be useful in reducing sea-to-air CO2 emissions and in neutralizing or offsetting the effects of ongoing ocean acidification. PMID:23729814

  7. Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production.

    PubMed

    Rau, Greg H; Carroll, Susan A; Bourcier, William L; Singleton, Michael J; Smith, Megan M; Aines, Roger D

    2013-06-18

    We experimentally demonstrate the direct coupling of silicate mineral dissolution with saline water electrolysis and H2 production to effect significant air CO2 absorption, chemical conversion, and storage in solution. In particular, we observed as much as a 10(5)-fold increase in OH(-) concentration (pH increase of up to 5.3 units) relative to experimental controls following the electrolysis of 0.25 M Na2SO4 solutions when the anode was encased in powdered silicate mineral, either wollastonite or an ultramafic mineral. After electrolysis, full equilibration of the alkalized solution with air led to a significant pH reduction and as much as a 45-fold increase in dissolved inorganic carbon concentration. This demonstrated significant spontaneous air CO2 capture, chemical conversion, and storage as a bicarbonate, predominantly as NaHCO3. The excess OH(-) initially formed in these experiments apparently resulted via neutralization of the anolyte acid, H2SO4, by reaction with the base mineral silicate at the anode, producing mineral sulfate and silica. This allowed the NaOH, normally generated at the cathode, to go unneutralized and to accumulate in the bulk electrolyte, ultimately reacting with atmospheric CO2 to form dissolved bicarbonate. Using nongrid or nonpeak renewable electricity, optimized systems at large scale might allow relatively high-capacity, energy-efficient (<300 kJ/mol of CO2 captured), and inexpensive (<$100 per tonne of CO2 mitigated) removal of excess air CO2 with production of carbon-negative H2. Furthermore, when added to the ocean, the produced hydroxide and/or (bi)carbonate could be useful in reducing sea-to-air CO2 emissions and in neutralizing or offsetting the effects of ongoing ocean acidification. PMID:23729814

  8. Behavior and enterotoxin production by coagulase negative Staphylococcus in cooked ham, reconstituted skimmed milk, and confectionery cream.

    PubMed

    Oliveira, Ana Maria; Miya, Norma Teruko Nago; Sant'Ana, Anderson S; Pereira, José Luiz

    2010-09-01

    In this study, the behavior and enterotoxin production by 10 different coagulase negative Staphylococcus (CNS) strains inoculated in cooked ham, reconstituted skimmed milk, and confectionery cream in the presence or absence of background microbiota have been investigated. After inoculation (103 CFU/g), foods were incubated at 25, 30, and 37 °C and aerobic mesophilic and CNS counts were carried out at 12, 24, 48, and 72 h. Staphylococcal enterotoxins (SE) detection was performed by SET-RPLA (Oxoid, Basingstoke, U.K.) and mini-Vidas® (bioMérieux, La Balme les Grottes, France). CNS counts increased during incubation and approached 10⁶ to 10⁷ CFU/g after 12 h at 37 °C in the 3 foods studied. At 25 °C, counts reached 10⁶ to 10⁷ CFU/g only after 24 to 48 h. The interference of background microbiota on CNS behavior was only observed when they grew in sliced cooked ham, which presented a high initial total count (10⁵ CFU/g). Significantly higher counts of CNS isolated from raw cow's milk in comparison with food handlers isolates were found in reconstituted milk and confectionery cream. Although CNS strains were able to produce SEA, SEB, and SED in culture media, in foods, in the presence or absence of background microbiota S. chromogenes LE0598 was the only strain able to produce SEs. Despite the scarcity of reports on CNS involvement with foodborne disease outbreaks, the results found here support the CNS growth and SE production in foods even in the presence of background microbiota and may affect food safety. PMID:21535559

  9. In Vitro Activities of Arylomycin Natural-Product Antibiotics against Staphylococcus epidermidis and Other Coagulase-Negative Staphylococci ▿ †

    PubMed Central

    Smith, Peter A.; Powers, Michael E.; Roberts, Tucker C.; Romesberg, Floyd E.

    2011-01-01

    The arylomycins are a class of natural-product antibiotics that act via the inhibition of type I signal peptidase (SPase), and we have found in diverse bacteria that their activity is limited by the presence of a resistance-conferring Pro residue in SPase that reduces inhibitor binding. We have also demonstrated that Staphylococcus epidermidis, which lacks this Pro residue, is extremely susceptible to the arylomycins. Here, to further explore the potential utility of the arylomycins, we report an analysis of the activity of a synthetic arylomycin derivative, arylomycin C16, against clinical isolates of S. epidermidis and other coagulase-negative staphylococci (CoNS) from distinct geographical locations. Against many important species of CoNS, including S. epidermidis, S. haemolyticus, S. lugdunensis, and S. hominis, we find that arylomycin C16 exhibits activity equal to or greater than that of vancomycin, the antibiotic most commonly used to treat CoNS infections. While the susceptibility was generally correlated with the absence of the previously identified Pro residue, several cases were identified where additional factors also appear to contribute. PMID:21189343

  10. Biosynthetic Products from a Nearshore-Derived Gram-Negative Bacterium Enable Reassessment of the Kailuin Depsipeptides

    PubMed Central

    Theodore, Christine M.; Lorig-Roach, Nicholas; Still, Patrick C.; Johnson, Tyler A.; Drašković, Marija; Schwochert, Joshua A.; Naphen, Cassandra N.; Crews, Mitchell S.; Barker, Simone A.; Valeriote, Frederick A.; Lokey, R. Scott; Crews, Phillip

    2015-01-01

    Sampling of California nearshore sediments resulted in the isolation of a Gram-negative bacterium, Photobacterium halotolerans, capable of producing unusual biosynthetic products. Liquid culture in artificial seawater-based media provided cyclic depsipeptides including four known compounds, kailuins B–E (2–5), and two new analogues, kailuins G and H (7 and 8). The structures of the new and known compounds were confirmed through extensive spectroscopic and Marfey's analyses. During the course of these studies, a correction was made to the previously reported double-bond geometry of kailuin D (4). Additionally, through the application of a combination of derivatization with Mosher's reagent and extensive 13C NMR shift analysis, the previously unassigned chiral center at position C-3 of the β-acyloxy group of all compounds was determined. To evaluate bioactivity and structure–activity relationships, the kailuin core (13) and kailuin lactam (14) were prepared by chiral synthesis using an Fmoc solid-phase peptide strategy followed by solution-phase cyclization. All isolated compounds and synthetic cores were assayed for solid tumor cell cytotoxicity and showed only minimal activity, contrary to other published reports. Additional phenotypic screenings were done on 4 and 5, with little evidence of activity. PMID:25699470

  11. Safety Evaluation of the Coagulase-Negative Staphylococci Microbiota of Salami: Superantigenic Toxin Production and Antimicrobial Resistance

    PubMed Central

    Soares Casaes Nunes, Raquel; Mere Del Aguila, Eduardo; Paschoalin, Vânia Margaret Flosi

    2015-01-01

    The risks of contracting staphylococci food poisoning by the consumption of improperly manufactured salami and the possibility of this food being reservoirs for antibiotic resistance were evaluated. Nineteen coagulase-negative staphylococci (CNS) strains were found in commercial and artisanal salami. The species in commercial salami were S. saprophyticus, S. sciuri, S. xylosus, and S. carnosus. Artisanal salami showed S. succinus, S. epidermidis, and S. hominis but no S. carnosus. Phylogenetic analyses grouped the strains into three major staphylococcal species groups, comprised of 4 refined clusters with similarities superior to 90%. Fifteen strains harbored multiple enterotoxin genes, with high incidence of seb/sec and sea, 57% and 50%, respectively, intermediate incidence of sed/seh/selm and sei/seln/tst-H, 33% and 27%, correspondingly, and low incidence of see/selj/selo and seg, of respectively 13% and 1%. Real time RT-PCR and enzyme-linked-immunosorbent assays confirmed the enterotoxigenicity of the strains, which expressed and produced enterotoxins in vitro. The CNS strains showed multiresistance to several antimicrobials of therapeutic importance in both human and veterinarian medicine, such as β-lactams, vancomycin, and linezolid. The effective control of undue staphylococci in fermented meat products should be adopted to prevent or limit the risk of food poisoning and the spread of antimicrobial-resistant strains. PMID:26697486

  12. Leydig cell number and sperm production decrease induced by chronic ametryn exposure: a negative impact on animal reproductive health.

    PubMed

    Dantas, T A; Cancian, G; Neodini, D N R; Mano, D R S; Capucho, C; Predes, F S; Pulz, R Barbieri; Pigoso, A A; Dolder, H; Severi-Aguiar, G D C

    2015-06-01

    Ametryn is an herbicide used to control broadleaf and grass weeds and its acute and chronic toxicity is expected to be low. Since toxicological data on ametryn is scarce, the aim of this study was to evaluate rat reproductive toxicity. Thirty-six adult male Wistar rats (90 days) were divided into three groups: Co (control) and T1 and T2 exposed to 15 and 30 mg/kg/day of ametryn, respectively, for 56 days. Testicular analysis demonstrated that ametryn decreased sperm number per testis, daily sperm production, and Leydig cell number in both treated groups, although little perceptible morphological change has been observed in seminiferous tubule structure. Lipid peroxidation was higher in group T2, catalase activity decreased in T1 group, superoxide dismutase activity diminished, and a smaller number of sulphydryl groups of total proteins were verified in both exposed groups, suggesting oxidative stress. These results showed negative ametryn influence on the testes and can compromise animal reproductive performance and survival. PMID:25561257

  13. Production and Characteristics of Raw-Starch-Digesting α-Amylase from a Protease-Negative Aspergillus ficum Mutant

    PubMed Central

    Hayashida, Shinsaku; Teramoto, Yuji

    1986-01-01

    Mutational experiments were carried out to decrease the protease productivity of Aspergillus ficum IFO 4320 by using N-methyl-N′-nitro-N-nitrosoguanidine. A protease-negative mutant, M-33, exhibited higher α-amylaseactivity than the parent strain under submerged culture at 30°C for 24 h. About 70% of the total α-amylase activity in the M-33 culture filtrate was adsorbed onto starch granules. The electrophoretically homogeneous preparation of raw-starch-adsorbable α-amylase (molecular weight, 88,000), acid stable at pH 2, showed intensive raw-starch-digesting activity, dissolving corn starch granules completely. The preparation also exhibited a high synergistic effect with glucoamylase I. A mutant, M-72, with higher protease activity produced a raw cornstarch-unadsorbable α-amylase. The purified enzyme (molecular weight, 54,000), acid unstable, showed no digesting activity on raw corn starch and a lower synergistic effect with glucoamylase I in the hydrolysis of raw corn starch. The fungal α-amylase was therefore divided into two types, a novel type of raw-starch-digesting enzyme and a conventional type of raw-starch-nondigesting enzyme. Images PMID:16347204

  14. MicroRNA-487b Is a Negative Regulator of Macrophage Activation by Targeting IL-33 Production.

    PubMed

    Xiang, Yang; Eyers, Fiona; Herbert, Cristan; Tay, Hock L; Foster, Paul S; Yang, Ming

    2016-04-15

    MicroRNAs (miRNAs) are short noncoding RNAs that regulate a broad spectrum of biological processes, including immune responses. Although the contributions of miRNAs to the function of immune cells are beginning to emerge, their specific roles remain largely unknown. IL-33 plays an important role in macrophage activation for innate host defense and proinflammatory responses. In this study, we report that miR-487b can suppress the levels of mRNA and protein for IL-33 during the differentiation of bone marrow-derived macrophages (BMDMs). This results in inhibition of IL-33-induced expression of Ag-presenting and costimulatory molecules and proinflammatory mediators. A luciferase assay showed that miR-487b binds to the IL-33 3'-untranslated region. We also confirmed that IL-33 directly promotes the activation of BMDMs by increasing the expression of MHC class I, MHC class II, CD80/CD86, and inducible NO synthase (iNOS) in a dose-dependent manner. Exposure of BMDMs to the TLR4 ligand, LPS, decreased miR-487b expression, increased IL-33 transcript levels, and induced the production of proinflammatory mediators (e.g., iNOS, IL-1β, IL-6, and TNF-α). Treatment with a specific inhibitor of miR-487b function also resulted in increased levels of IL-33 mRNA, which augmented LPS-induced expression of these inflammatory mediators in macrophages. Collectively, our results indicate that miR-487b plays a negative regulatory role in macrophages by controlling the levels of IL-33 transcript and protein to fine-tune innate immune host defense and proinflammatory responses of these cells. Thus, miR-487b plays an important role in the regulation of macrophage homeostasis and activation by targeting IL-33 transcripts. PMID:26936882

  15. Reciprocated cross sucking between dairy calves after weaning off milk does not appear to negatively affect udder health or production.

    PubMed

    Vaughan, Alison; Miguel-Pacheco, Giuliana G; Marie de Passillé, Anne; Rushen, Jeffrey

    2016-07-01

    Cross sucking by dairy calves occurs most commonly before weaning, but is of most concern in older animals where it has been claimed to cause mastitis and udder damage. Providing ad libitum milk allowance via a teat and gradual weaning reduces cross sucking, but low levels of this behavior still persist. Our aims were to understand why this behavior persists in some calves after weaning off milk and to examine whether individuals which are cross sucked postweaning are more likely to sustain teat injury or develop mastitis during their first lactation. Fifty-six female Holstein calves were housed in groups of 8 and fed milk, grain, and hay ad libitum from automated feeders. During weaning, milk allowance was gradually reduced according to grain intake. Cross sucking was recorded using overhead video cameras (5 observation periods of 72h). The effects of weaning on cross sucking were examined; to examine whether cross sucking affected udder health, all incidences of damaged quarters or clinical and sub-clinical mastitis in the first lactation were recorded, as was milk production. The overall level of cross sucking after weaning, at 4 to 5mo of age, was low and a small proportion of individuals accounted for the majority of events. The duration of cross sucking that occurred at 4 to 5mo of age was correlated with the amount of cross sucking done before and immediately after weaning. After weaning, the calves that cross sucked did so on certain calves, with the most sucked calf within each pen accounting for 73.98% of all cross-sucking events. No relationship was found between cross sucking and being cross sucked in the period before weaning but a positive correlation was found by 4 to 5mo of age. The majority of calves reduced or ceased cross sucking after weaning. Individuals still observed to be cross sucking by 4 to 5mo of age had formed pairs with other cross-sucking individuals and cross-sucking events occurred almost exclusively between these pairs. Cows that

  16. Negative ion production by backscattering from alkali-metal surfaces bombarded by ions of hydrogen and deuterium

    SciTech Connect

    Schneider, P.J.

    1980-03-01

    Measurements have been made of the total backscattered D/sup -/ and H/sup -/ yields from thick, clean targets of Cs, Rb, K, Na, and Li, bombarded with H/sub 2//sup +/, H/sub 3//sup +/, D/sub 2//sup +/, and D/sub 3//sup +/ with incident energies from 0.15 to 4.0 keV/nucleus. All of the measurements were made at background pressures less than 10/sup -9/ Torr and the alkali-metal targets were evaporated onto a cold substrate (T = 77K) in situ to assure thick, uncontaminated targets. Measurements of the H/sup -/ yield from various transition metal targets with thin coverages of alkali-metals have also been made as a function of the surface work function. The negative ion yields are discussed in terms of the probabilities of reflection of the incident particles, of formation of the negative ion at the surface and of the survival of the negative ion leaving the surface. For each thick alkali-metal target, the negative ion yield measurements have been used in a least squares fit to determine two parameters in a theoretically derived expression for the negative ion yield. The parameters obtained from a thick Na target have been used to calculate the yield from a Cu target with thin coverage of Na (such that the surface work function is equal to thick Na).

  17. Negative mass

    NASA Astrophysics Data System (ADS)

    Hammond, Richard T.

    2015-03-01

    Some physical aspects of negative mass are examined. Several unusual properties, such as the ability of negative mass to penetrate any armor, are analysed. Other surprising effects include the bizarre system of negative mass chasing positive mass, naked singularities and the violation of cosmic censorship, wormholes, and quantum mechanical results as well. In addition, a brief look into the implications for strings is given.

  18. Nonlinear acoustics: Periodic waveguide, finite-amplitude propagation in a medium having a distribution of relaxation processes, and production of an isolated negative pulse in water

    NASA Astrophysics Data System (ADS)

    Blackstock, David T.

    1993-08-01

    Research on nonlinear acoustics has been performed during the 12-month period ending 30 September 1993. The following projects were completed: (1) propagation in a periodic waveguide, (2) finite-amplitude propagation in a medium having a distribution of relaxation processes, and (3) production of an isolated negative pulse in water. Public communication of the research was accomplished through three theses, four oral papers, one journal article published, four journal articles submitted, and one paper in a symposium proceedings.

  19. Antimicrobial susceptibility and beta-lactamase production of selected gram-negative bacilli from two Croatian hospitals: MYSTIC study results.

    PubMed

    Bedenic, B; Goic-Barisic, I; Budimir, A; Tonkic, M; Mihajkevic, L J; Novak, A; Sviben, M; Plecko, V; Punda-Polic, V; Kalenic, S

    2010-06-01

    The meropenem yearly Susceptibility Test Information Collection (MYSTIC) programme is a global, longitudinal resistance surveillance network that monitors the activity of meropenem and compares its activity with other broadspectrum antimicrobial agents. We now report the antimicrobial efficacy of meropenem compared to other broad-spectrum agents within the selective Gram-negative pathogen groups from two Croatian Hospitals investigated between 2002-2007. A total of 1510 Gram-negative pathogens were tested and the minimum-inhibitory concentrations (MICs) were determined by broth microdilution method according to CLSI.There was no resistance to either imipenem or meropenem observed for Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis in both medical centers. High resistance rates of K. pneumoniae to ceftazidime (18%), cefepime (17%) and gentamicin (39%) are raising concern. Acinetobacter baumannii turned out to be the most resistant Gram-negative bacteria with 81% resistant to ceftazidime, 73% to cefepime, 69% to gentamicin and 71% to ciprofloxacin. Almost 20% of Pseudomonas aeruginosa strains were resistant to imipenem, 13% to meropenem, 69% to gentamicin and 38% to ciprofloxacin.The prevalence of extended-spectrum beta-lactamases (ESBLs) in E. coli was 10% and in K. pneumoniae 49%. PCR and sequencing of the amplicons revealed the presence of SHV-5 in nine E. coli strains and additional tem-1 beta-lactamase five strains. Five K. pneumoniae strains were positive for bla(SHV-5 )gene. Eight ESBL positive Enterobacter spp. strains were found to produce tem and CtX-m beta-lactamases. Plasmid-mediated AmpC beta-lactamases were not found among K. pneumoniae, E. coli and Enterobacter spp. Three A. baumannii strains from Zagreb University Center were identified by multiplex PCR as OXA-58 like producers. Six A. baumannii strains from Split University Center were found to possess an ISAba1 insertion sequence upstream of bla(OXA-51 )gene. According to our results

  20. Production of slime by coagulase-negative staphylococci (CNS) isolated from clinical and subclinical mastitis in cows.

    PubMed

    Bochniarz, M; Wawron, W; Szczubiał, M

    2014-01-01

    The aim of the study was to evaluate the slime-producing ability of coagulase-negative staphylococci (CNS) isolated from clinical and subclinical mastitis in cows. The study was carried out on 100 isolates of CNS obtained from milk of 86 cows from farms located in the Lublin region (Poland). Slime-producing ability was observed in over half of coagulase-negative staphylococci (54.0% of isolated CNS), including 19 isolates of methicillin-resistant staphylococci (95.5% of all MRCNS). Of 22 isolates of CNS responsible for the clinical form of mastitis, 20 isolates (90.9%) produced slime: S. xylosus (7 isolates), S. haemolyticus (6 isolates), S. chromogenes (4 isolates), and S. sciuri (3 isolates), including 9 isolates of MRCNS (45.0%). The remaining 34 isolates of CNS (43.6%) with the ability to produce this exopolysaccharide were isolated from the milk of cows with subclinical form of mastitis: S. xylosus (12 isolates), S. sciuri (9 isolates), S. chromogenes (6 isolates), S. haemolyticus (3 isolates), S. warneri (3 isolates) and S. saprophyticus (1 isolate), including 10 isolates of MRCNS (12.8%). PMID:25286652

  1. Detection of aqueous phase chemical warfare agent degradation products by negative mode ion mobility time-of-flight mass spectrometry [IM(tof)MS].

    PubMed

    Steiner, Wes E; Harden, Charles S; Hong, Feng; Klopsch, Steve J; Hill, Herbert H; McHugh, Vincent M

    2006-02-01

    The use of negative ion monitoring mode with an atmospheric pressure ion mobility orthogonal reflector time-of-flight mass spectrometer [IM(tof)MS] to detect chemical warfare agent (CWA) degradation products from aqueous phase samples has been determined. Aqueous phase sampling used a traditional electrospray ionization (ESI) source for sample introduction and ionization. Certified reference materials (CRM) of CWA degradation products for the detection of Schedule 1, 2, or 3 toxic chemicals or their precursors as defined by the chemical warfare convention (CWC) treaty verification were used in this study. A mixture of six G-series nerve related CWA degradation products (EMPA, IMPA, EHEP, IHEP, CHMPA, and PMPA) and their related collision induced dissociation (CID) fragment ions (MPA and EPA) were found in each case to be clearly resolved and detected using the IM(tof)MS instrument in negative ion monitoring mode. Corresponding ions, masses, drift times, K(o) values, and signal intensities for each of the CWA degradation products are reported. PMID:16413205

  2. ChiS histidine kinase negatively regulates the production of chitinase ChiC in Streptomyces peucetius.

    PubMed

    Rabbind Singh, Amrathlal; Senthamaraikannan, Paranthaman; Thangavel, Chitra; Danda, Ravikanth; Pandian, Shunmugiah Karutha; Dharmalingam, Kuppamuthu

    2014-01-01

    Computational analysis of sequence homology of the chiSRC gene cluster, encoding a chitinase in Streptomyces peucetius, showed that the gene cluster could be a two-component regulon comprising a sensor kinase (chiS) and a response regulator (chiR). To prove that the ChiSRC is an authentic two-component system, the chiS gene was cloned and expressed in E.coli and the purified protein was used for biochemical analysis. In this report, we provide biochemical evidence to show that the sensor kinase encoded by chiS gene indeed is a histidine kinase capable of autophosphorylation and the histidine 144 residue of the ChiS protein is the phosphate acceptor. An insertion mutation at the chiS locus led to overproduction chitinase protein in S. peucetius implying that the chiC gene is negatively regulated by the two-component system. PMID:23972296

  3. Structural elucidation of monoterpene oxidation products by ion trap fragmentation using on-line atmospheric pressure chemical ionisation mass spectrometry in the negative ion mode.

    PubMed

    Warscheid, B; Hoffmann, T

    2001-01-01

    Based on ion trap mass spectrometry, an on-line method is described which provides valuable information on the molecular composition of structurally complex organic aerosols. The investigated aerosols were generated from the gas-phase ozonolysis of various C(10)H(16)-terpenes (alpha-pinene, beta-pinene, 3-carene, sabinene, limonene), and directly introduced into the ion source of the mass spectrometer. Negative ion chemical ionisation at atmospheric pressure (APCI(-)) enabled the detection of multifunctional carboxylic acid products by combining inherent sensitivity and molecular weight information. Sequential low-energy collision-induced product ion fragmentation experiments (MS(n)) were performed in order to elucidate characteristic decomposition pathways of the compounds. Dicarboxylic acids, oxocarboxylic acids and hydroxyketocarboxylic acid products could be clearly distinguished by multistage on-line MS. Furthermore, sabinonic acid and two C(9)-ether compounds were tentatively identified for the first time by applying on-line APCI(-)-MS(n). PMID:11746892

  4. Production of porcine TNFα by ADAM17-mediated cleavage negatively regulates porcine reproductive and respiratory syndrome virus infection.

    PubMed

    Li, Ren; Guo, Longjun; Gu, Weihong; Luo, Xiaolei; Zhang, Jian; Xu, Yunfei; Tian, Zhijun; Feng, Li; Wang, Yue

    2016-06-01

    Porcine reproductive and respiratory syndrome virus (PRRSV) causes a series of inflammatory reactions in sites of infection, companied by the upregulation of key inflammatory factor TNFα. TNFα, which serves as a "master regulator" of inflammatory cytokine production, is mainly produced by macrophages at the early infection stage. Here, we showed that porcine alveolar macrophages produced a great amount of soluble TNFα upon PRRSV infection. Furthermore, we found that TNFα had great anti-PRRSV effect. Next, by using inhibitor and genetic modification methods, we addressed that porcine TNFα production was mediated by ADAM17. Lastly, we proved that the (78)Arg-Ser-Ser motif of porcine TNFα contained the essential information for efficient cleavage. Taken together, our findings provide the direct evidence that ADAM17 cleaves porcine TNFα, which represents a new view for identifying potential therapeutic targets in anti-PRRSV therapy. PMID:26724939

  5. Denitrification and N2O:N2 production in temperate grasslands: processes, measurements, modelling and mitigating negative impacts.

    PubMed

    Saggar, Surinder; Jha, N; Deslippe, J; Bolan, N S; Luo, J; Giltrap, D L; Kim, D-G; Zaman, M; Tillman, R W

    2013-11-01

    In this review we explore the biotic transformations of nitrogenous compounds that occur during denitrification, and the factors that influence denitrifier populations and enzyme activities, and hence, affect the production of nitrous oxide (N2O) and dinitrogen (N2) in soils. Characteristics of the genes related to denitrification are also presented. Denitrification is discussed with particular emphasis on nitrogen (N) inputs and dynamics within grasslands, and their impacts on the key soil variables and processes regulating denitrification and related gaseous N2O and N2 emissions. Factors affecting denitrification include soil N, carbon (C), pH, temperature, oxygen supply and water content. We understand that the N2O:N2 production ratio responds to the changes in these factors. Increased soil N supply, decreased soil pH, C availability and water content generally increase N2O:N2 ratio. The review also covers approaches to identify and quantify denitrification, including acetylene inhibition, (15)N tracer and direct N2 quantification techniques. We also outline the importance of emerging molecular techniques to assess gene diversity and reveal enzymes that consume N2O during denitrification and the factors affecting their activities and consider a process-based approach that can be used to quantify the N2O:N2 product ratio and N2O emissions with known levels of uncertainty in soils. Finally, we explore strategies to reduce the N2O:N2 product ratio during denitrification to mitigate N2O emissions. Future research needs to focus on evaluating the N2O-reducing ability of the denitrifiers to accelerate the conversion of N2O to N2 and the reduction of N2O:N2 ratio during denitrification. PMID:23260378

  6. Chloride stress triggers maturation and negatively affects the postharvest quality of persimmon fruit. Involvement of calyx ethylene production.

    PubMed

    Besada, Cristina; Gil, Rebeca; Bonet, Luis; Quiñones, Ana; Intrigliolo, Diego; Salvador, Alejandra

    2016-03-01

    In recent years many hectares planted with persimmon trees in E Spain have been diagnosed with chloride toxicity. An effect of this abiotic stress on fruit quality has been reported in different crops. However, the impact of chloride stress on persimmon fruit quality is unknown. The harvest and postharvest quality of persimmons harvested from trees that manifest different intensities of chloride toxicity foliar symptoms was evaluated herein. Our results revealed that fruits from trees under chloride stress conditions underwent chloride accumulation in the calyx, which was more marked the greater the salt stress intensity trees were exposed to. Increased chloride concentrations in the calyx stimulated ethylene production in this tissue. In the fruits affected by slight and moderate chloride stress, calyx ethylene production accelerated the maturity process, as reflected by increased fruit colour and diminished fruit firmness. In the fruits under severe chloride stress, the high ethylene levels in the calyx triggered autocatalytic ethylene production in other fruit tissues, which led fruit maturity to drastically advance. In these fruits effectiveness of CO2 deastringency treatment was not complete and fruit softening enhanced during the postharvest period. Moreover, chloride stress conditions had a marked effect on reducing fruit weight, even in slightly stressed trees. PMID:26807935

  7. Utilizing upper hybrid resonance for high density plasma production and negative ion generation in a downstream region

    SciTech Connect

    Sahu, Debaprasad; Bhattacharjee, Sudeep

    2012-09-15

    Localized wave-induced resonances are created by microwaves launched directly into a multicusp (MC) plasma device in the k Up-Tack B mode, where k is the wave vector and B is the static magnetic field. The resonance zone is identified as upper hybrid resonance (UHR), and lies r = {approx}22 mm away from the MC boundary. Measurement of radial wave electric field intensity confirms the right hand cutoff of the wave (r = 22.5-32.1 mm) located near the UHR zone. A sharp rise in the corresponding electron temperature in the resonance region by {approx}13 eV from its value away from resonance at r = 0, is favorable for the generation of vibrationally excited molecules of hydrogen. A transverse magnetic filter allows cold electrons ({approx}1-2 eV) to pass into the downstream region where they generate negative ions by dissociative attachment. Measurements of electron energy distribution function (EEDF) support the viewpoint. H{sup -} current density of {approx}0.26 mA/cm{sup 2} is obtained at a wave power density of {approx}3 W/cm{sup 2} at 2.0 mTorr pressure, which agrees reasonably well with results obtained from a steady state model using particle balance equations.

  8. Scrutinizing the Scaffolds of Marine Biosynthetics from Different Source Organisms: Gram-Negative Cultured Bacterial Products Enter Center Stage

    PubMed Central

    Still, Patrick C.; Johnson, Tyler A.; Theodore, Christine M.; Loveridge, Steven T.; Crews, Phillip

    2014-01-01

    Compounds from macro marine organisms are presumed to owe their biosynthetic origins to associated microbial symbionts, although few definitive examples exist. An upsurge in the recent literature from 2012 to 2013 has shown that four compounds previously reported from macro marine organisms are in fact biosynthesized by non-photosynthetic Gram-negative bacteria (NPGNB). Structural parallels between compounds isolated from macro marine organisms and NPGNB producers form the basis of this review. Although less attention has been given to investigating the chemistry of NPGNB sources, there exists a significant list of structural parallels between NPGNB and macro marine organism-derived compounds. Alternatively, of the thousands of compounds isolated from Gram-positive actinomycetes, few structural parallels with macro marine organisms are known. A summary of small molecules isolated from marine NPGNB sources is presented, including compounds isolated from marine myxobacteria. From this assemblage of structural parallels and diverse chemical structures, it is hypothesized that the potential for the discovery of inspirational molecules from NPGNB sources is vast and that the recent spike in the literature of macro marine compounds owing their biosynthetic origin to NPGNB producers represents a turning point in the field. PMID:24571234

  9. GPER negatively regulates TNFα-induced IL-6 production in human breast cancer cells via NF-κB pathway.

    PubMed

    Okamoto, Mariko; Mizukami, Yoichi

    2016-05-31

    Estrogen is known to have anti-inflammatory effects, that are thought to be mediated by the classical estrogen receptors (ERs), ERα and ERβ. G protein coupled estrogen receptor1 (GPER) is a novel membrane-type estrogen receptor that can mediate non-genomic estrogenic responses. Although there have been several reports asserting that the participation of GPER in anti-inflammatory effects is induced by estrogen, the role of GPER remains poorly understood. In this study, we investigated the involvement of GPER in the regulation of a representative inflammatory cytokine, IL-6. We first examined the expression of IL-6 mRNA by TNFα stimulation in the transfection of GPER-expression plasmid into HeLa cells. Exogenous GPER significantly inhibited TNFα-induced IL-6 expression, and blocked NF-κB promoter activity inducing the expression of IL-6 in a dose-dependent manner. The promoter activity was restored almost to control level by transfection with the C-terminal deletion mutant of GPER. Similar results have been observed in endogenous GPER using SKBR3 cells which do not express the classical ERs. The data have been validated by treatment of GPER with siRNA. These findings indicate that GPER negatively regulates TNFα-induced IL-6 expression, probably through inhibition of NF-κB promoter activity by a signal(s) derived from the C-terminal region of GPER. PMID:26888479

  10. Production and properties of keratinolytic proteases from three novel Gram-negative feather-degrading bacteria isolated from Brazilian soils.

    PubMed

    Bach, Evelise; Daroit, Daniel Joner; Corrêa, Ana Paula Folmer; Brandelli, Adriano

    2011-11-01

    The keratinolytic potential and protease properties of three novel Gram-negative feather-degrading bacteria isolated from Brazilian soils was described. Aeromonas hydrophila K12, Chryseobacterium indologenes A22 and Serratia marcescens P3 were able to degrade feather meal, producing high amounts of soluble proteins and forming thiol groups. The proteases of strains K12, A22 and P3 had optimal pH of 8.0, 7.5 and 6.0, respectively; this last is an uncommon feature for bacterial keratinases. The optimal temperature was in the range 45-55°C. All three proteases were active towards azokeratin and were inhibited by EDTA, suggesting that they are keratinolytic metalloproteases. The proteolytic activity of K12 was stimulated by organic solvents and the detergent SDS, suggesting its potential application for detergent formulations and peptide synthesis. Strains A22, K12 and P3 have great potential for use in biotechnological processes involving hydrolysis of keratinous byproducts. PMID:21526391

  11. An alternative splicing product of the murine trpv1 gene dominant negatively modulates the activity of TRPV1 channels.

    PubMed

    Wang, Chunbo; Hu, Hong-Zhen; Colton, Craig K; Wood, Jackie D; Zhu, Michael X

    2004-09-01

    Transient receptor potential vanilloid 1 (TRPV1), or vanilloid receptor 1, is the founding member of the vanilloid type of TRP superfamily of nonselective cation channels. TRPV1 is activated by noxious heat, acid, and alkaloid irritants as well as several endogenous ligands and is sensitized by inflammatory factors, thereby serving important functions in detecting noxious stimuli in the sensory system and pathological states in different parts of the body. Whereas numerous studies have been carried out using the rat and human TRPV1 cDNA, the mouse TRPV1 cDNA has not been characterized. Here, we report molecular cloning of two TRPV1 cDNA variants from dorsal root ganglia of C57BL/6 mice. The deduced proteins are designated TRPV1alpha and TRPV1beta and contain 839 and 829 amino acids, respectively. TRPV1beta arises from an alternative intron recognition signal within exon 7 of the trpv1 gene. We found a predominant expression of TRPV1alpha in many tissues and significant expression of TRPV1beta in dorsal root ganglia, skin, stomach, and tongue. When expressed in HEK 293 cells or Xenopus oocytes, TRPV1alpha formed a Ca(2+)-permeable channel activated by ligands known to stimulate TRPV1. TRPV1beta was not functional by itself but its co-expression inhibited the function of TRPV1alpha. Furthermore, although both isoforms were synthesized at a similar rate, less TRPV1beta than TRPV1alpha protein was found in cells and on the cell surface, indicating that the beta isoform is highly unstable. Our data suggest that TRPV1beta is a naturally occurring dominant-negative regulator of the responses of sensory neurons to noxious stimuli. PMID:15234965

  12. Mathematical modelling reveals properties of TcdC required for it to be a negative regulator of toxin production in Clostridium difficile.

    PubMed

    Jabbari, Sara; Cartman, Stephen T; King, John R

    2015-03-01

    The role of the protein TcdC in pathogenicity of the bacterium Clostridium difficile is currently unclear: conflicting reports suggest it is either a negative regulator of toxin production or, on the other hand, has no effect on virulence at all. We exploit a theoretical approach by taking what is known about the network of proteins surrounding toxin production by C. difficile and translating this into a mathematical model. From there it is possible to investigate a range of possible interactions (using numerical and asymptotic analyses), identifying properties of TcdC which would make it a realistic candidate as a toxin inhibitor. Our findings imply that if TcdC is really an inhibitor of toxin production then TcdC production should be at least as fast as that of the protein TcdR and TcdC should remain in the cells throughout growth. These are experimentally-testable hypotheses and are equally applicable to alternative candidates for toxin production inhibition. PMID:24687436

  13. TRIM68 Negatively Regulates IFN-β Production by Degrading TRK Fused Gene, a Novel Driver of IFN-β Downstream of Anti-Viral Detection Systems

    PubMed Central

    Wynne, Claire; Lazzari, Elisa; Smith, Siobhán; McCarthy, Eoghan M.; Ní Gabhann, Joan; Kallal, Lara E.; Higgs, Rowan; Cryan, Sally Ann; Biron, Christine A.; Jefferies, Caroline A.

    2014-01-01

    In recent years members of the tripartite motif-containing (TRIM) family of E3 ubiquitin ligases have been shown to both positively and negatively regulate viral defence and as such are emerging as compelling targets for modulating the anti-viral immune response. In this study we identify TRIM68, a close homologue of TRIM21, as a novel regulator of Toll-like receptor (TLR)- and RIG-I-like receptor (RLR)-driven type I IFN production. Proteomic analysis of TRIM68-containing complexes identified TRK-fused gene (TFG) as a potential TRIM68 target. Overexpression of TRIM68 and TFG confirmed their ability to associate, with TLR3 stimulation appearing to enhance the interaction. TFG is a known activator of NF-κB via its ability to interact with inhibitor of NF-κB kinase subunit gamma (IKK-γ) and TRAF family member-associated NF-κB activator (TANK). Our data identifies a novel role for TFG as a positive regulator of type I IFN production and suggests that TRIM68 targets TFG for lysosomal degradation, thus turning off TFG-mediated IFN-β production. Knockdown of TRIM68 in primary human monocytes resulted in enhanced levels of type I IFN and TFG following poly(I:C) treatment. Thus TRIM68 targets TFG, a novel regulator of IFN production, and in doing so turns off and limits type I IFN production in response to anti-viral detection systems. PMID:24999993

  14. Coagulase-negative staphylococci isolated from two cases of toxic shock syndrome lack superantigenic activity, but induce cytokine production.

    PubMed

    Lina, G; Fleer, A; Etienne, J; Greenland, T B; Vandenesch, F

    1996-01-01

    Two strains of Staphylococcus epidermidis isolated from patients with toxic shock symptoms have been reported to carry genes related to S. aureus enterotoxins B and C by dot-blot hybridisation, although the corresponding superantigenic toxins were not detected immunologically. We here show that these strains produce no superantigens capable of stimulating proliferation of human mononuclear leukocytes or rabbit splenocytes, and that no DNA homologous to the seb or sec genes can be detected by PCR. However, stimulation of human monocytes by whole killed bacteria induced dose-dependent production of the cytokines TNF alpha, IL-1 beta and IL-6, which may be responsible for the clinical symptoms in these patients. PMID:8821402

  15. Phylogenetic profiles of in-house microflora in drains at a food production facility: comparison and biocontrol implications of Listeria-positive and -negative bacterial populations.

    PubMed

    Fox, Edward M; Solomon, Katie; Moore, John E; Wall, Patrick G; Fanning, Séamus

    2014-06-01

    Listeria species experience complex interactions with other microorganisms, which may promote growth and colonization of the organism in local environments or negatively affect them. This study investigated the microbial community at a food production facility, examining interactions between Listeria and the associated microbiome. Listeria species can be transferred between zones in the production environment by individuals or equipment, and drains may act as a reservoir for the organism, reflecting the microbial flora potentially in the production environment. Drains that were colonized by Listeria species and those determined to be free of Listeria were examined. In each case, 16S rRNA gene analysis was performed using the PhyloChip platform. Some general similarities in bacterial population structure were observed when Listeria-negative and -positive drain communities were compared, with some distinct differences also noted. These included increased populations of the genera Prevotella and Janthinobacterium associated with the absence of Listeria species, whereas Enterococcus and Rhodococcus were in higher abundance in drains colonized by Listeria species. Based on these results, a selection of bacterial species were grown in coculture biofilm with a Listeria monocytogenes strain identified as having colonized a drain at the facility. Mixed-species biofilm experiments showed that Janthinobacterium inhibited attachment and subsequent biofilm formation of L. monocytogenes; however, Enterococcus gallinarum significantly increased it. The results of this study suggest the microbial community in food processing facilities can impact the colonization of Listeria species and that influencing the microbiome in favor of antilisterial species may reduce the colonization of Listeria species and limit the likelihood of product/process contamination. PMID:24657862

  16. Characterization of OxyR as a negative transcriptional regulator that represses catalase production in Corynebacterium diphtheriae.

    PubMed

    Kim, Ju-Sim; Holmes, Randall K

    2012-01-01

    Corynebacterium diphtheriae and Corynebacterium glutamicum each have one gene (cat) encoding catalase. In-frame Δcat mutants of C. diphtheriae and C. glutamicum were hyper-sensitive to growth inhibition and killing by H(2)O(2). In C. diphtheriae C7(β), both catalase activity and cat transcription decreased ~2-fold during transition from exponential growth to early stationary phase. Prototypic OxyR in Escherichia coli senses oxidative stress and it activates katG transcription and catalase production in response to H(2)O(2). In contrast, exposure of C. diphtheriae C7(β) to H(2)O(2) did not stimulate transcription of cat. OxyR from C. diphtheriae and C. glutamicum have 52% similarity with E. coli OxyR and contain homologs of the two cysteine residues involved in H(2)O(2) sensing by E. coli OxyR. In-frame ΔoxyR deletion mutants of C. diphtheriae C7(β), C. diphtheriae NCTC13129, and C. glutamicum were much more resistant than their parental wild type strains to growth inhibition by H(2)O(2). In the C. diphtheriae C7(β) ΔoxyR mutant, cat transcripts were about 8-fold more abundant and catalase activity was about 20-fold greater than in the C7(β) wild type strain. The oxyR gene from C. diphtheriae or C. glutamicum, but not from E. coli, complemented the defect in ΔoxyR mutants of C. diphtheriae and C. glutamicum and decreased their H(2)O(2) resistance to the level of their parental strains. Gel-mobility shift, DNaseI footprint, and primer extension assays showed that purified OxyR from C. diphtheriae C7(β) bound, in the presence or absence of DTT, to a sequence in the cat promoter region that extends from nucleotide position -55 to -10 with respect to the +1 nucleotide in the cat ORF. These results demonstrate that OxyR from C. diphtheriae or C. glutamicum functions as a transcriptional repressor of the cat gene by a mechanism that is independent of oxidative stress induced by H(2)O(2). PMID:22438866

  17. TPL-2-ERK1/2 signaling promotes host resistance against intracellular bacterial infection by negative regulation of type I IFN production.

    PubMed

    McNab, Finlay W; Ewbank, John; Rajsbaum, Ricardo; Stavropoulos, Evangelos; Martirosyan, Anna; Redford, Paul S; Wu, Xuemei; Graham, Christine M; Saraiva, Margarida; Tsichlis, Philip; Chaussabel, Damien; Ley, Steven C; O'Garra, Anne

    2013-08-15

    Tuberculosis, caused by Mycobacterium tuberculosis, remains a leading cause of mortality and morbidity worldwide, causing ≈ 1.4 million deaths per year. Key immune components for host protection during tuberculosis include the cytokines IL-12, IL-1, and TNF-α, as well as IFN-γ and CD4(+) Th1 cells. However, immune factors determining whether individuals control infection or progress to active tuberculosis are incompletely understood. Excess amounts of type I IFN have been linked to exacerbated disease during tuberculosis in mouse models and to active disease in patients, suggesting tight regulation of this family of cytokines is critical to host resistance. In addition, the immunosuppressive cytokine IL-10 is known to inhibit the immune response to M. tuberculosis in murine models through the negative regulation of key proinflammatory cytokines and the subsequent Th1 response. We show in this study, using a combination of transcriptomic analysis, genetics, and pharmacological inhibitors, that the TPL-2-ERK1/2 signaling pathway is important in mediating host resistance to tuberculosis through negative regulation of type I IFN production. The TPL-2-ERK1/2 signaling pathway regulated production by macrophages of several cytokines important in the immune response to M. tuberculosis as well as regulating induction of a large number of additional genes, many in a type I IFN-dependent manner. In the absence of TPL-2 in vivo, excess type I IFN promoted IL-10 production and exacerbated disease. These findings describe an important regulatory mechanism for controlling tuberculosis and reveal mechanisms by which type I IFN may promote susceptibility to this important disease. PMID:23842752

  18. fundTPL-2 – ERK1/2 Signaling Promotes Host Resistance against Intracellular Bacterial Infection by Negative Regulation of Type I Interferon Production3

    PubMed Central

    McNab, Finlay W.; Ewbank, John; Rajsbaum, Ricardo; Stavropoulos, Evangelos; Martirosyan, Anna; Redford, Paul S.; Wu, Xuemei; Graham, Christine M.; Saraiva, Margarida; Tsichlis, Philip; Chaussabel, Damien; Ley, Steven C.; O’Garra, Anne

    2013-01-01

    Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), remains a leading cause of mortality and morbidity worldwide, causing approximately 1.4 million deaths per year. Key immune components for host protection during tuberculosis include the cytokines IL-12, IL-1 and TNF-α, as well as IFN-γ and CD4+ Th1 cells. However, immune factors determining whether individuals control infection or progress to active tuberculosis are incompletely understood. Excess amounts of type I interferon have been linked to exacerbated disease during tuberculosis in mouse models and to active disease in patients, suggesting tight regulation of this family of cytokines is critical to host resistance. In addition, the immunosuppressive cytokine IL-10 is known to inhibit the immune response to Mtb in murine models through the negative regulation of key pro-inflammatory cytokines and the subsequent Th1 response. We show here, using a combination of transcriptomic analysis, genetics and pharmacological inhibitors that the TPL-2-ERK1/2 signaling pathway is important in mediating host resistance to tuberculosis through negative regulation of type I interferon production. The TPL-2-ERK1/2 signalling pathway regulated production by macrophages of several cytokines important in the immune response to Mtb as well as regulating induction of a large number of additional genes, many in a type I IFN dependent manner. In the absence of TPL-2 in vivo, excess type I interferon promoted IL-10 production and exacerbated disease. These findings describe an important regulatory mechanism for controlling tuberculosis and reveal mechanisms by which type I interferon may promote susceptibility to this important disease. PMID:23842752

  19. The production of alpha/beta and gamma/delta double negative (DN) T-cells and their role in the maintenance of pregnancy.

    PubMed

    Chapman, John C; Chapman, Fae M; Michael, Sandra D

    2015-01-01

    The ability of the thymus gland to convert bone marrow-derived progenitor cells into single positive (SP) T-cells is well known. In this review we present evidence that the thymus, in addition to producing SP T-cells, also has a pathway for the production of double negative (DN) T-cells. The existence of this pathway was noted during our examination of relevant literature to determine the cause of sex steroid-induced thymocyte loss. In conducting this search our objective was to answer the question of whether thymocyte loss is the end product of a typical interaction between the reproductive and immune systems, or evidence that the two systems are incompatible. We can now report that "thymocyte loss" is a normal process that occurs during the production of DN T-cells. The DN T-cell pathway is unique in that it is mediated by thymic mast cells, and becomes functional following puberty. Sex steroids initiate the development of the pathway by binding to an estrogen receptor alpha located in the outer membrane of the mast cells, causing their activation. This results in their uptake of extracellular calcium, and the production and subsequent release of histamine and serotonin. Lymphatic vessels, located in the subcapsular region of the thymus, respond to the two vasodilators by undergoing a substantial and preferential uptake of gamma/delta and alpha/beta DN T- cells. These T- cells exit the thymus via efferent lymphatic vessels and enter the lymphatic system.The DN pathway is responsible for the production of three subsets of gamma/delta DN T-cells and one subset of alpha/beta DN T-cells. In postpubertal animals approximately 35 % of total thymocytes exit the thymus as DN T-cells, regardless of sex. In pregnant females, their levels undergo a dramatic increase. Gamma/delta DN T-cells produce cytokines that are essential for the maintenance of pregnancy. PMID:26164866

  20. A Spontaneous Dominant-Negative Mutation within a 35S::AtMYB90 Transgene Inhibits Flower Pigment Production in Tobacco

    PubMed Central

    Velten, Jeff; Cakir, Cahid; Cazzonelli, Christopher I.

    2010-01-01

    Background In part due to the ease of visual detection of phenotypic changes, anthocyanin pigment production has long been the target of genetic and molecular research in plants. Specific members of the large family of plant myb transcription factors have been found to play critical roles in regulating expression of anthocyanin biosynthetic genes and these genes continue to serve as important tools in dissecting the molecular mechanisms of plant gene regulation. Findings A spontaneous mutation within the coding region of an Arabidopsis 35S::AtMYB90 transgene converted the activator of plant-wide anthocyanin production to a dominant-negative allele (PG-1) that inhibits normal pigment production within tobacco petals. Sequence analysis identified a single base change that created a premature nonsense codon, truncating the encoded myb protein. The resulting mutant protein lacks 78 amino acids from the wild type C-terminus and was confirmed as the source of the white-flower phenotype. A putative tobacco homolog of AtMYB90 (NtAN2) was isolated and found to be expressed in flower petals but not leaves of all tobacco plants tested. Using transgenic tobacco constitutively expressing the NtAN2 gene confirmed the NtAN2 protein as the likely target of PG-1-based inhibition of tobacco pigment production. Conclusions Messenger RNA and anthocyanin analysis of PG-1Sh transgenic lines (and PG-1Sh x purple 35S::NtAN2 seedlings) support a model in which the mutant myb transgene product acts as a competitive inhibitor of the native tobacco NtAN2 protein. This finding is important to researchers in the field of plant transcription factor analysis, representing a potential outcome for experiments analyzing in vivo protein function in test transgenic systems that over-express or mutate plant transcription factors. PMID:20360951

  1. The ica Operon and Biofilm Production in Coagulase-Negative Staphylococci Associated with Carriage and Disease in a Neonatal Intensive Care Unit

    PubMed Central

    de Silva, G. D. I.; Kantzanou, M.; Justice, A.; Massey, R. C.; Wilkinson, A. R.; Day, N. P. J.; Peacock, S. J.

    2002-01-01

    Coagulase-negative staphylococci (CoNS) are a major cause of sepsis in the neonatal intensive care unit (NICU). We evaluated the hypothesis that the ica operon and biofilm production are associated with CoNS disease in this setting. CoNS associated with bacteremia or blood culture contamination and from the skin of infants with CoNS bacteremia or healthy controls were obtained during a prospective case-control study on a busy NICU. A total of 180 strains were identified, of which 122 (68%) were Staphylococcus epidermidis and the remainder were S. capitis (n = 29), S. haemolyticus (n = 11), S. hominis (n = 9), S. warneri (n = 8), and S. auricularis (n = 1). The presence of the genes icaA, icaB, icaC, and icaD was determined by PCR, and biofilm production was examined using qualitative (Congo red agar [CRA]) and quantitative (microtiter plate) techniques. There were no significant differences in the presence of the ica operon or CRA positivity among the four groups of strains. However, quantitative biofilm production was significantly greater in strains isolated from either the blood or the skin of neonates with S. epidermidis bacteremia. We conclude that the quantity of biofilm produced may be associated with the ability to cause CoNS infection. This conclusion suggests that the regulation of biofilm expression may play a central role in the disease process. PMID:11825946

  2. TBK1-like transcript negatively regulates the production of IFN and IFN-stimulated genes through RLRs-MAVS-TBK1 pathway.

    PubMed

    Zhang, Lin; Chen, Wen Qin; Hu, Yi Wei; Wu, Xiao Man; Nie, P; Chang, Ming Xian

    2016-07-01

    TANK-binding kinase 1 (TBK1) is an essential serine/threonine-protein kinase required for Toll-like receptor (TLR)- and retinoic acid-inducible gene I (RIG-I) -mediated induction of type I IFN and host antiviral defense. In the present study, TBK1-like transcript, namely TBK1L, was cloned from zebrafish. Compared with TBK1, TBK1L contains an incomplete S_TKc domain, and lacks UBL_TBK1_like domain. Realtime PCR showed that TBK1L was constitutively produced in embryos, early larvae and ZF4 cells, and unchanged in ZF4 cells following SVCV infection. Overexpression of TBK1 but not TBK1L resulted in significant activation of zebrafish IFN1 and IFN3 promoters. Similarly, TBK1L had little impact on the antiviral state of the cells. However, the overexpression of TBK1L negatively regulated the induction of zebrafish IFN1 and/or IFN3 promoters mediated by the retinoic acid-inducible gene I-like receptors (RLRs), MAVS and TBK1. In addition, the overexpression of TBK1L in zebrafish embryos led to the decreased production of many IFN-stimulated genes induced by TBK1. Collectively, these data support that zebrafish TBK1L negatively regulates RLRs-MAVS-TBK1 pathway. PMID:27060200

  3. Hydrogen negative ion production in a 14 GHz electron cyclotron resonance compact ion source with a cone-shaped magnetic filter.

    PubMed

    Ichikawa, T; Kasuya, T; Kenmotsu, T; Maeno, S; Nishiura, M; Shimozuma, T; Yamaoka, H; Wada, M

    2014-02-01

    The plasma electrode structure of a 14 GHz ECR ion source was modified to enlarge the plasma volume of low electron temperature region. The result shows that the extracted beam current reached about 0.6 mA/cm(2) with about 40 W microwave power. To investigate the correlation between the volume of the low electron temperature region and the H(-) current, a vacuum ultraviolet (VUV) spectrometer had been installed to observe light emission in the VUV wavelength range from the plasma. From the results of the negative ion beam current and that from VUV spectrometry, production rate of vibrationally excited hydrogen molecule seems to be enhanced by increasing the volume of low electron temperature region. PMID:24593572

  4. Langmuir probes for SPIDER (source for the production of ions of deuterium extracted from radio frequency plasma) experiment: Tests in BATMAN (Bavarian test machine for negative ions)

    SciTech Connect

    Brombin, M. Spolaore, M.; Serianni, G.; Pomaro, N.; Taliercio, C.; Palma, M. Dalla; Pasqualotto, R.; Schiesko, L.

    2014-11-15

    A prototype system of the Langmuir probes for SPIDER (Source for the production of Ions of Deuterium Extracted from RF plasma) was manufactured and experimentally qualified. The diagnostic was operated in RF (Radio Frequency) plasmas with cesium evaporation on the BATMAN (BAvarian Test MAchine for Negative ions) test facility, which can provide plasma conditions as expected in the SPIDER source. A RF passive compensation circuit was realised to operate the Langmuir probes in RF plasmas. The sensors’ holder, designed to better simulate the bias plate conditions in SPIDER, was exposed to a severe experimental campaign in BATMAN with cesium evaporation. No detrimental effect on the diagnostic due to cesium evaporation was found during the exposure to the BATMAN plasma and in particular the insulation of the electrodes was preserved. The paper presents the system prototype, the RF compensation circuit, the acquisition system (as foreseen in SPIDER), and the results obtained during the experimental campaigns.

  5. Langmuir probes for SPIDER (source for the production of ions of deuterium extracted from radio frequency plasma) experiment: Tests in BATMAN (Bavarian test machine for negative ions)

    NASA Astrophysics Data System (ADS)

    Brombin, M.; Spolaore, M.; Serianni, G.; Pomaro, N.; Taliercio, C.; Palma, M. Dalla; Pasqualotto, R.; Schiesko, L.

    2014-11-01

    A prototype system of the Langmuir probes for SPIDER (Source for the production of Ions of Deuterium Extracted from RF plasma) was manufactured and experimentally qualified. The diagnostic was operated in RF (Radio Frequency) plasmas with cesium evaporation on the BATMAN (BAvarian Test MAchine for Negative ions) test facility, which can provide plasma conditions as expected in the SPIDER source. A RF passive compensation circuit was realised to operate the Langmuir probes in RF plasmas. The sensors' holder, designed to better simulate the bias plate conditions in SPIDER, was exposed to a severe experimental campaign in BATMAN with cesium evaporation. No detrimental effect on the diagnostic due to cesium evaporation was found during the exposure to the BATMAN plasma and in particular the insulation of the electrodes was preserved. The paper presents the system prototype, the RF compensation circuit, the acquisition system (as foreseen in SPIDER), and the results obtained during the experimental campaigns.

  6. Relationship between indole production and differentiation of Klebsiella species: indole-positive and -negative isolates of Klebsiella determined to be clonal.

    PubMed Central

    Maslow, J N; Brecher, S M; Adams, K S; Durbin, A; Loring, S; Arbeit, R D

    1993-01-01

    Klebsiellae are an important cause of nosocomial infections. The two clinically relevant species, Klebsiella pneumoniae and Klebsiella oxytoca, are differentiated by the ability to produce indole from tryptophan, K. oxytoca being indole positive. We report here the detailed biochemical and molecular analysis of two isolates of Klebsiella, cultured from the same urine specimen, that differed only in their ability to produce indole. The two isolates were identical as determined by ribotyping and pulsed-field gel electrophoresis, and they differed from 10 epidemiologically unrelated strains. Probing with the Escherichia coli tryptophanase operon, tna, revealed seven restriction fragment length polymorphisms (RFLP) among the 12 strains. The two index strains had identical RFLP; no single RFLP could account for all of the indole-positive or -negative strains. Thus, the identification of epidemiologically related strains of Klebsiella differing only in indole production may warrant further examination to determine whether the strains are clonal. Images PMID:8370726

  7. Hydrogen negative ion production in a 14 GHz electron cyclotron resonance compact ion source with a cone-shaped magnetic filter

    SciTech Connect

    Ichikawa, T.; Kasuya, T.; Wada, M.; Kenmotsu, T.; Maeno, S.; Nishiura, M.; Shimozuma, T.; Yamaoka, H.

    2014-02-15

    The plasma electrode structure of a 14 GHz ECR ion source was modified to enlarge the plasma volume of low electron temperature region. The result shows that the extracted beam current reached about 0.6 mA/cm{sup 2} with about 40 W microwave power. To investigate the correlation between the volume of the low electron temperature region and the H{sup −} current, a vacuum ultraviolet (VUV) spectrometer had been installed to observe light emission in the VUV wavelength range from the plasma. From the results of the negative ion beam current and that from VUV spectrometry, production rate of vibrationally excited hydrogen molecule seems to be enhanced by increasing the volume of low electron temperature region.

  8. Identification of BCAP-{sub L} as a negative regulator of the TLR signaling-induced production of IL-6 and IL-10 in macrophages by tyrosine phosphoproteomics

    SciTech Connect

    Matsumura, Takayuki; Oyama, Masaaki; Kozuka-Hata, Hiroko; Ishikawa, Kosuke; Inoue, Takafumi; Muta, Tatsushi; Semba, Kentaro; Inoue, Jun-ichiro

    2010-09-17

    Research highlights: {yields} Twenty five tyrosine-phosphorylated proteins in LPS-stimulated macrophages were determined. {yields} BCAP is a novel tyrosine-phosphorylated protein in LPS-stimulated macrophages. {yields} BCAP-{sub L} inhibits IL-6 and IL-10 production in LPS-stimulated macrophages. -- Abstract: Toll-like receptor (TLR) signaling in macrophages is essential for anti-pathogen responses such as cytokine production and antigen presentation. Although numerous reports suggest that protein tyrosine kinases (PTKs) are involved in cytokine induction in response to lipopolysaccharides (LPS; TLR4 ligand) in macrophages, the PTK-mediated signal transduction pathway has yet to be analyzed in detail. Here, we carried out a comprehensive and quantitative dynamic tyrosine phosphoproteomic analysis on the TLR4-mediated host defense system in RAW264.7 macrophages using stable isotope labeling by amino acids in cell culture (SILAC). We determined the temporal profiles of 25 proteins based on SILAC-encoded peptide(s). Of these, we focused on the tyrosine phosphorylation of B-cell adaptor for phosphatidylinositol 3-kinase (BCAP) because the function of BCAP remains unknown in TLR signaling in macrophages. Furthermore, Bcap has two distinct transcripts, a full-length (Bcap-{sub L}) and an alternatively initiated or spliced (Bcap-{sub S}) mRNA, and little is known about the differential functions of the BCAP-{sub L} and BCAP-{sub S} proteins. Our study showed, for the first time, that RNAi-mediated selective depletion of BCAP-{sub L} enhanced IL-6 and IL-10 production but not TNF-{alpha} production in TLR ligand-stimulated macrophages. We propose that BCAP-{sub L} (but not BCAP-{sub S}) is a negative regulator of the TLR-mediated host defense system in macrophages.

  9. Characterization of an Sf-rhabdovirus-negative Spodoptera frugiperda cell line as an alternative host for recombinant protein production in the baculovirus-insect cell system.

    PubMed

    Maghodia, Ajay B; Geisler, Christoph; Jarvis, Donald L

    2016-06-01

    Cell lines derived from the fall armyworm, Spodoptera frugiperda (Sf), are widely used as hosts for recombinant protein production in the baculovirus-insect cell system (BICS). However, it was recently discovered that these cell lines are contaminated with a virus, now known as Sf-rhabdovirus [1]. The detection of this adventitious agent raised a potential safety issue that could adversely impact the BICS as a commercial recombinant protein production platform. Thus, we examined the properties of Sf-RVN, an Sf-rhabdovirus-negative Sf cell line, as a potential alternative host. Nested RT-PCR assays showed Sf-RVN cells had no detectable Sf-rhabdovirus over the course of 60 passages in continuous culture. The general properties of Sf-RVN cells, including their average growth rates, diameters, morphologies, and viabilities after baculovirus infection, were virtually identical to those of Sf9 cells. Baculovirus-infected Sf-RVN and Sf9 cells produced equivalent levels of three recombinant proteins, including an intracellular prokaryotic protein and two secreted eukaryotic glycoproteins, and provided similar N-glycosylation patterns. In fact, except for the absence of Sf-rhabdovirus, the only difference between Sf-RVN and Sf9 cells was SF-RVN produced higher levels of infectious baculovirus progeny. These results show Sf-RVN cells can be used as improved, alternative hosts to circumvent the potential safety hazard associated with the use of Sf-rhabdovirus-contaminated Sf cells for recombinant protein manufacturing with the BICS. PMID:26923062

  10. The Histone Methyltransferase Smyd2 Is a Negative Regulator of Macrophage Activation by Suppressing Interleukin 6 (IL-6) and Tumor Necrosis Factor α (TNF-α) Production

    PubMed Central

    Xu, Guiliang; Liu, Guilin; Xiong, Sidong; Liu, Haiyan; Chen, Xi; Zheng, Biao

    2015-01-01

    SET and MYND domain-containing 2 (Smyd2), a histone 3 lysine 4- and histone 3 lysine 36 (H3K36)-specific methyltransferase, plays critical roles in cardiac development and tumorigenesis. However, the role of Smyd2 in immunity and inflammation remains poorly understood. In this study, we report that Smyd2 is a novel negative regulator for macrophage activation and M1 polarization. Elevated Smyd2 expression suppresses the production of proinflammatory cytokines, including IL-6 and TNF, and inhibits the expression of important cell surface molecules, including major MHC-II and costimulatory molecules. Furthermore, macrophages with high Smyd2 expression inhibit Th-17 cell differentiation but promote regulatory T cell differentiation as a result of increased TGF-β production and decreased IL-6 secretion. In macrophages, Smyd2 specifically facilitates H3K36 dimethylation at Tnf and Il6 promoters to suppress their transcription and inhibits NF-κB and ERK signaling. Therefore, our data demonstrate that epigenetic modification by Smyd2-mediated H3K36 dimethylation at Tnf and Il6 promoters plays an important role in the regulation of macrophage activation during inflammation. PMID:25583990

  11. Investigation of N-acyl homoserine lactone (AHL) molecule production in Gram-negative bacteria isolated from cooling tower water and biofilm samples.

    PubMed

    Haslan, Ezgi; Kimiran-Erdem, Ayten

    2013-09-01

    In this study, 99 Gram-negative rod bacteria were isolated from cooling tower water, and biofilm samples were examined for cell-to-cell signaling systems, N-acyl homoserine lactone (AHL) signal molecule types, and biofilm formation capacity. Four of 39 (10 %) strains isolated from water samples and 14 of 60 (23 %) strains isolated from biofilm samples were found to be producing a variety of AHL signal molecules. It was determined that the AHL signal molecule production ability and the biofilm formation capacity of sessile bacteria is higher than planktonic bacteria, and there was a statistically significant difference between the AHL signal molecule production of these two groups (p < 0.05). In addition, it was found that bacteria belonging to the same species isolated from cooling tower water and biofilm samples produced different types of AHL signal molecules and that there were different types of AHL signal molecules in an AHL extract of bacteria. In the present study, it was observed that different isolates of the same strains did not produce the same AHLs or did not produce AHL molecules, and bacteria known as AHL producers did not produce AHL. These findings suggest that detection of signal molecules in bacteria isolated from cooling towers may contribute to prevention of biofilm formation, elimination of communication among bacteria in water systems, and blockage of quorum-sensing controlled virulence of these bacteria. PMID:23250628

  12. IL-10-induced microRNA-187 negatively regulates TNF-α, IL-6, and IL-12p40 production in TLR4-stimulated monocytes.

    PubMed

    Rossato, Marzia; Curtale, Graziella; Tamassia, Nicola; Castellucci, Monica; Mori, Laura; Gasperini, Sara; Mariotti, Barbara; De Luca, Mariacristina; Mirolo, Massimiliano; Cassatella, Marco A; Locati, Massimo; Bazzoni, Flavia

    2012-11-01

    IL-10 is a potent anti-inflammatory molecule that, in phagocytes, negatively targets cytokine expression at transcriptional and posttranscriptional levels. Posttranscriptional checkpoints also represent the specific target of a recently discovered, evolutionary conserved class of small silencing RNAs known as "microRNAs" (miRNAs), which display the peculiar function of negatively regulating mRNA processing, stability, and translation. In this study, we report that activation of primary human monocytes up-regulates the expression of miR-187 both in vitro and in vivo. Accordingly, we identify miR-187 as an IL-10-dependent miRNA playing a role in IL-10-mediated suppression of TNF-α, IL-6, and the p40 subunit of IL-12 (IL-12p40) produced by primary human monocytes following activation of Toll-like receptor 4 (TLR4). Ectopic expression of miR-187 consistently and selectively reduces TNFα, IL-6, and IL-12p40 produced by LPS-activated monocytes. Conversely, the production of LPS-induced TNF-α, IL-6, and IL-12p40 is increased significantly when miR-187 expression is silenced. Our data demonstrate that miR-187 directly targets TNF-α mRNA stability and translation and indirectly decreases IL-6 and IL-12p40 expression via down-modulation of IκBζ, a master regulator of the transcription of these latter two cytokines. These results uncover an miRNA-mediated pathway controlling cytokine expression and demonstrate a central role of miR-187 in the physiological regulation of IL-10-driven anti-inflammatory responses. PMID:23071313

  13. Perioperative transfusion of leukocyte depleted blood products in gastric cancer patients negatively influences oncologic outcome: A retrospective propensity score weighted analysis on 610 curatively resected gastric cancer patients.

    PubMed

    Reim, Daniel; Strobl, Andreas N; Buchner, Christian; Schirren, Rebekka; Mueller, Werner; Luppa, Peter; Ankerst, Donna Pauler; Friess, Helmut; Novotny, Alexander

    2016-07-01

    The influence of perioperative transfusion (PT) on outcome following surgery for gastric cancer (GC) remains controversial, with randomized trials lacking and observational series confounded by patient risk factors. This analysis determines the association between reception of leukocyte-depleted blood products and post-operative survival for GC.Data from 610 patients who underwent curative surgery for GC in a German tertiary care clinic from 2001 to 2013 were included. Kaplan-Meier survival curves and Cox proportional hazards regression were applied to determine the association of PT and clinical and patient risk factors for overall and relapse-free survival. Propensity score analysis was performed to adjust for observational biases in reception of PT.Higher Union International Contre le Cancer/American Joint Committee on Cancer (UICC/AJCC)-stages (P <0.001), postoperative complications and severity according to the Clavien-Dindo (CD) classification (P <0.001), PT (P = 0.02), higher age (P <0.001), and neoadjuvant chemotherapy (P <0.001) were related to increased mortality rates. Higher UICC-stages (P <0.001), neoadjuvant chemotherapy (P <0.001), and type of surgery (P = 0.02) were independently associated with increased relapse rates. Patients were more likely to receive PT with higher age (P = 0.05), surgical extension to adjacent organs/structures (P = 0.002), tumor location (P = 0.003), and female gender (P = 0.03). In the adjusted propensity score weighted analysis, PT remained associated with an increased risk of death (hazard ratio (HR): 1.31, 95% CI: 1.01-1.69, P = 0.04).Because of the association of PT with negative influence on patient survival following resection for GC, risks from application of blood products should be weighed against the potential benefits. PMID:27442682

  14. Regulation of the phosphate regulon in Escherichia coli K-12: regulation of the negative regulatory gene phoU and identification of the gene product.

    PubMed Central

    Nakata, A; Amemura, M; Shinagawa, H

    1984-01-01

    The phoU gene is one of the negative regulatory genes of the pho regulon of Escherichia coli. The DNA fragment carrying phoU has been cloned on pBR322 (Amemura et al., J. Bacteriol. 152:692-701, 1982). Further subcloning, Tn1000 insertion inactivation, and complementation tests localized the phoU gene within a 1.1-kilobase region on the cloned DNA fragment. The gene product of phoU was identified by the maxicell method as a protein with an approximate molecular weight of 27,000. A hybrid plasmid that contains a phoU'-lac'Z fused gene was constructed in vitro. This plasmid enabled us to study phoU gene expression by measuring the beta-galactosidase level in the cells. The plasmid was introduced into various regulatory mutants related to the pho regulon, and phoU gene expression in these strains was studied under limited and excess phosphate conditions. It was found that phoU is expressed at a higher level when the cells are cultured under the excess phosphate condition. The higher phoU expression was observed in a phoB mutant and a phoR-phoM double mutant. The implications of these findings for the regulation of pho genes are discussed. Images PMID:6090402

  15. Molecular analysis of the pathogenicity locus and polymorphism in the putative negative regulator of toxin production (TcdC) among Clostridium difficile clinical isolates.

    PubMed

    Spigaglia, Patrizia; Mastrantonio, Paola

    2002-09-01

    The pathogenicity locus (PaLoc) of Clostridium difficile contains toxin A and B genes and three accessory genes, including tcdD and tcdC, which are supposed to code for the positive and negative regulators of toxin expression, respectively. Different studies have described variations in C. difficile toxin A and B genes, but little is known about C. difficile variants for the accessory genes. The PaLoc of several C. difficile clinical isolates was investigated by three different PCR methods with the aim to identify variant strains. Of the toxinogenic C. difficile strains examined, 25% showed variations. No correlation between C. difficile variant strains and key patient groups was found. Interestingly, all of these strains showed a variant tcdC gene. Three different tcdC alleles were identified, and one of these had a nonsense mutation which reduced the TcdC protein from 232 to 61 amino acids. It is possible that different TcdC variants affect toxin production differently, a hypothesis with important implications for the pathogenic potential of variant C. difficile strains. PMID:12202595

  16. Comparison of Coagulase-Negative Staphylococci Isolated from Blood Cultures as a True Bacteremia Agent and Contaminant in Terms of Slime Production and Methicillin Resistance

    PubMed Central

    Uyanik, Muhammet Hamidullah; Yazgi, Halil; Ozden, Kemalettin; Erdil, Zeynep; Ayyildiz, Ahmet

    2014-01-01

    Objective: The aim of this study is to determine the species distribution, slime activity, and methicillin resistance of coagulase-negative staphylococci (CoNS) isolated from blood cultures as either contaminants or true bacteremia agents. Materials and Methods: In this study, 13.268 blood culture samples sent to our laboratory from various clinics during a two-year period were examined in terms of the presence of CoNS to clarify whether the isolates are true bacteremia agents, as defined by Centers for Disease Control and Prevention (CDC) criteria. The slime activities of true bacteremia agents (58 CoNS strains) and contaminants (50 randomly selected CoNS strains) were investigated by the Christensen method. The methicillin susceptibilities of the strains were determined by the disk diffusion method. Results: Although the frequency of slime production was 39.7% among the true bacteremia CoNS agents, it was 18% in CoNS that were judged to be contaminants (p<0.05). S. epidermidis was the most frequently isolated species for both the true bacteremia agent group (56.9%) and contaminant group (74%). Additionally, S. epidermidis was the bacterium most frequently characterized as slime producing in both groups. The methicillin resistance of slime-producing CoNS was determined to be 82.6% for the true bacteremia agent group and 77.8% for the contaminant group. Conclusion: The presence of slime activity in CoNS isolated from blood culture samples is supportive evidence that they are most likely the agents of true bacteremia cases. PMID:25610309

  17. Identification and molecular phylogeny of coagulase-negative staphylococci isolates from Minas Frescal cheese in southeastern Brazil: Superantigenic toxin production and antibiotic resistance.

    PubMed

    Casaes Nunes, Raquel Soares; Pires de Souza, Camilla; Pereira, Karen Signori; Del Aguila, Eduardo Mere; Flosi Paschoalin, Vânia Margaret

    2016-04-01

    Minas Frescal is a typical Brazilian fresh cheese and one of the most popular dairy products in the country. This white soft, semiskimmed, nonripened cheese with high moisture content is obtained by enzymatic coagulation of cow milk using calf rennet or coagulants, usually in industrial dairy plants, but is also manufactured in small farms. Contamination of Minas Frescal by several staphylococci has been frequently reported. Coagulase-negative staphylococci (CNS) strains are maybe the most harmful, as they are able to produce heat-stable enterotoxins with super antigenic activities in food matrices, especially in dairy products such as soft cheeses. The aim of the present study was to investigate the presence of CNS strains in Minas Frescal marketed in southeastern Brazil concerning the risk of staphylococci food poisoning by the consumption of improperly manufactured cheese and the possibility of these food matrices being a reservoir of staphylococcal resistance to antimicrobials. Ten distinct CNS strains were found in 6 cheeses from distinct brands. The most frequent species were Staphylococcus saprophyticus (40%), Staphylococcus xylosus (30%), Staphylococcus sciuri (20%), and Staphylococcus piscifermentans (10%). Three strains were identified to the Staphylococcus genera. Three major species groups composed of 3 refined clusters were grouped by phylogenetic analyses with similarities over to 90%. All CNS strains carried multiple enterotoxin genes, with high incidence of sea and seb (90 and 70%, respectively), followed by sec/see, seh/sei, and sed with intermediate incidence (60, 50, and 40%, respectively), and, finally, seg/selk/selq/selr and selu with the lowest incidence (20 and 10%, respectively). Real-time reverse transcription PCR and ELISA assays confirmed the enteroxigenic character of the CNS strains, which expressed and produced the enterotoxins in vitro. The CNS strains showed multiresistance to antimicrobial agents such as β-lactams, vancomycin, and

  18. Heifers infected with coagulase-negative staphylococci in early lactation have fewer cases of clinical mastitis and higher milk production in their first lactation than noninfected heifers.

    PubMed

    Piepers, S; Opsomer, G; Barkema, H W; de Kruif, A; De Vliegher, S

    2010-05-01

    Intramammary infections (IMI) in recently calved dairy heifers are more common than was formerly believed but their relevance for future performance has been studied only rarely. In the present study, the association between the IMI status of fresh heifers and their subsequent udder health, milk production, and culling in first lactation was explored. Quarter milk samples were collected between 1 and 4 d in milk (DIM) and between 5 and 8 DIM from 191 dairy heifers in 20 dairy herds for bacteriological culturing and somatic cell count (SCC) analysis. Monthly milk recording data including composite milk SCC and test-day milk yield (MY) were obtained for the first 285 DIM or until culling. Farmer-recorded clinical mastitis cases were available. Data were analyzed using mixed models and survival analysis. Approximately 80% of the fresh heifers (79.8%) had at least one culture-positive quarter. Coagulase-negative staphylococci (CNS) were the most frequently isolated pathogens (72%), followed by esculin-positive streptococci (4.6%) and Staphylococcus aureus (3.5%). Overall geometric mean SCC at quarter level decreased between the first and second samplings from 348,000 to 116,000 cells/mL. Heifers infected with CNS had an intermediate average test-day SCC (84,000 cells/mL) during the first 285 DIM compared with noninfected heifers (53,000 cells/mL) and heifers infected with major pathogens (195,000 cells/mL). Heifers infected with major pathogens had a much lower average daily MY (18.3kg) during first lactation compared with noninfected animals (21.3kg). That CNS-infected heifers out-produced their noninfected counterparts could be at least partially explained by their significantly lower incidence of clinical mastitis (incidence risk 3.6 vs. 21.0%) during first lactation compared with noninfected heifers. We conclude that although CNS cause the majority of IMI in heifers around calving, they should not be a reason for serious concern. PMID:20412915

  19. Plasma fluorescent oxidation products and risk of estrogen receptor-negative breast cancer in the Nurses' Health Study and Nurses' Health Study II.

    PubMed

    Hirko, Kelly A; Fortner, Renée T; Hankinson, Susan E; Wu, Tianying; Eliassen, A Heather

    2016-07-01

    Findings from epidemiologic studies of oxidative stress biomarkers and breast cancer have been mixed, although no studies have focused on estrogen receptor-negative (ER-) tumors which may be more strongly associated with oxidative stress. We examined prediagnostic plasma fluorescent oxidation products (FlOP), a global biomarker of oxidative stress, and risk of ER- breast cancer in a nested case-control study in the Nurses' Health Study and Nurses' Health Study II. ER- breast cancer cases (n = 355) were matched to 355 controls on age, month/time of day of blood collection, fasting status, menopausal status, and menopausal hormone use. Conditional logistic regression models were used to examine associations of plasma FlOP at three emission wavelengths (FlOP_360, FlOP_320, and FlOP_400) and risk of ER- breast cancer. We did not observe any significant associations between FlOP measures and risk of ER- breast cancer overall; the RRQ4vsQ1 (95 %CI) 0.70 (0.43-1.13), p trend = 0.09 for FlOP_360; 0.91(0.56-1.46), p trend = 0.93 for FlOP_320; and 0.62 (0.37-1.03), p trend = 0.10 for FlOP_400. Results were similar in models additionally adjusted for total carotenoid levels and in models stratified by age and total carotenoids. Although high (vs. low) levels of FIOP_360 and FIOP_400 were associated with lower risk of ER- breast cancer in lean women (body mass index (BMI) < 25 kg/m(2)) but not in overweight/obese women, these differences were not statistically significant (pint = 0.23 for FlOP_360; pint = 0.37 for FlOP_400). Our findings suggest that positive associations of plasma FlOP concentrations and ER- breast cancer risk are unlikely. PMID:27294610

  20. Negative Emissions Technology

    NASA Astrophysics Data System (ADS)

    Day, Danny

    2006-04-01

    Although `negative emissions' of carbon dioxide need not, in principle, involve use of biological processes to draw carbon out of the atmosphere, such `agricultural' sequestration' is the only known way to remove carbon from the atmosphere on time scales comparable to the time scale for anthropogenic increases in carbon emissions. In order to maintain the `negative emissions' the biomass must be used in such a way that the resulting carbon dioxide is separated and permanently sequestered. Two options for sequestration are in the topsoil and via geologic carbon sequestration. The former has multiple benefits, but the latter also is needed. Thus, although geologic carbon sequestration is viewed skeptically by some environmentalists as simply a way to keep using fossil fuels---it may be a key part of reversing accelerating climate forcing if rapid climate change is beginning to occur. I will first review the general approach of agricultural sequestration combined with use of resulting biofuels in a way that permits carbon separation and then geologic sequestration as a negative emissions technology. Then I discuss the process that is the focus of my company---the EPRIDA cycle. If deployed at a sufficiently large scale, it could reverse the increase in CO2 concentrations. I also estimate of benefits --carbon and other---of large scale deployment of negative emissions technologies. For example, using the EPRIDA cycle by planting and soil sequestering carbon in an area abut In 3X the size of Texas would remove the amount of carbon that is being accumulated worldwide each year. In addition to the atmospheric carbon removal, the EPRIDA approach also counters the depletion of carbon in the soil---increasing topsoil and its fertility; reduces the excess nitrogen in the water by eliminating the need for ammonium nitrate fertilizer and reduces fossil fuel reliance by providing biofuel and avoiding natural gas based fertilizer production.

  1. Polarized negative ions

    SciTech Connect

    Haeberli, W.

    1981-04-01

    This paper presents a survey of methods, commonly in use or under development, to produce beams of polarized negative ions for injection into accelerators. A short summary recalls how the hyperfine interaction is used to obtain nuclear polarization in beams of atoms. Atomic-beam sources for light ions are discussed. If the best presently known techniques are incorporated in all stages of the source, polarized H/sup -/ and D/sup -/ beams in excess of 10 ..mu..A can probably be achieved. Production of polarized ions from fast (keV) beams of polarized atoms is treated separately for atoms in the H(25) excited state (Lamb-Shift source) and atoms in the H(1S) ground state. The negative ion beam from Lamb-Shift sources has reached a plateau just above 1 ..mu..A, but this beam current is adequate for many applications and the somewhat lower beam current is compensated by other desirable characteristics. Sources using fast polarized ground state atoms are in a stage of intense development. The next sections summarize production of polarized heavy ions by the atomic beam method, which is well established, and by optical pumping, which has recently been demonstrated to yield very large nuclear polarization. A short discussion of proposed ion sources for polarized /sup 3/He/sup -/ ions is followed by some concluding remarks.

  2. Meningitis - gram-negative

    MedlinePlus

    Gram-negative meningitis ... Acute bacterial meningitis can be caused by Gram-negative bacteria. Meningococcal and H. influenzae meningitis are caused by Gram-negative bacteria and are covered in detail in other articles. This article ...

  3. Electric Potential Near The Extraction Region In Negative Ion Sources With Surface Produced Negative Ions

    SciTech Connect

    Fukano, A.; Hatayama, A.

    2011-09-26

    The potential distribution near the extraction region in negative ion sources for the plasma with the surface produced negative ions is studied analytically. The potential is derived analytically by using a plasma-sheath equation, where negative ions produced on the Plasma Grid (PG) surface are considered in addition to positive ions and electrons. A negative potential peak is formed in the sheath region near the PG surface for the case of strong surface production of negative ions or for low energy negative ions. Negative ions are reflected by the negative potential peak near the PG and returned to the PG surface. This reflection mechanism by the negative potential peak possibly becomes a factor in negative ion extraction. It is also indicated that the potential difference between the plasma region and the wall decreases by the surface produced negative ions. This also has the possibility to contribute to the negative ion extraction.

  4. High Basal Activity of the PTPN22 Gain-of-Function Variant Blunts Leukocyte Responsiveness Negatively Affecting IL-10 Production in ANCA Vasculitis

    PubMed Central

    Cao, Yali; Yang, Jiajin; Colby, Kerry; Hogan, Susan L.; Hu, Yichun; Jennette, Caroline E.; Berg, Elisabeth A.; Zhang, Youkang; Jennette, J. Charles; Falk, Ronald J.; Preston, Gloria A.

    2012-01-01

    Consequences of expression of the protein tyrosine phosphatase nonreceptor 22 (PTPN22) gain-of-function variant were evaluated in leukocytes from patients with anti-neutrophil cytoplasmic autoantibody (ANCA) disease. The frequency of the gain-of-function allele within the Caucasian patient cohort was 22% (OR 1.45), compared to general American Caucasian population (16.5%, p = 0.03). Examination of the basal phosphatase activity of PTPN22 gain-of-function protein indicated persistently elevated activity in un-stimulated peripheral leukocytes, while basal activity was undetectable in leukocytes from patients without the gain-of-function variant. To examine consequences of persistently high PTPN22 activity, the activation status of ERK and p38 MAPK were analyzed. While moderate levels of activated ERK were observed in controls, it was undetectable in leukocytes expressing PTPN22 gain-of-function protein and instead p38MAPK was up-regulated. IL-10 transcription, reliant on the ERK pathway, was negatively affected. Over the course of disease, patients expressing variant PTPN22 did not show a spike in IL-10 transcription as they entered remission in contrast to controls, implying that environmentally triggered signals were blunted. Sustained activity of PTPN22, due to the gain-of-function mutation, acts as a dominant negative regulator of ERK activity leading to blunted cellular responsiveness to environmental stimuli and expression of protective cytokines. PMID:22880107

  5. Evaluation of Five Chromogenic Agar Media and the Rosco Rapid Carb Screen Kit for Detection and Confirmation of Carbapenemase Production in Gram-Negative Bacilli

    PubMed Central

    Gilmour, Matthew W.; DeGagne, Pat; Nichol, Kim; Karlowsky, James A.

    2014-01-01

    An efficient workflow to screen for and confirm the presence of carbapenemase-producing Gram-negative bacilli was developed by evaluating five chromogenic screening agar media and two confirmatory assays, the Rapid Carb screen test (Rosco Diagnostica A/S, Taastrup, Denmark) and the modified Hodge test. A panel of 150 isolates was used, including 49 carbapenemase-producing isolates representing a variety of β-lactamase enzyme classes. An evaluation of analytical performance, assay cost, and turnaround time indicated that the preferred workflow (screening test followed by confirmatory testing) was the chromID Carba agar medium (bioMérieux, Marcy l'Étoile, France), followed by the Rapid Carb screen test, yielding a combined sensitivity of 89.8% and a specificity of 100%. As an optional component of the workflow, a determination of carbapenemase gene class via molecular means could be performed subsequent to confirmatory testing. PMID:25355764

  6. THE E3 UBIQUITIN LIGASE RO52 NEGATIVELY REGULATES IFN-β PRODUCTION POST-PATHOGEN RECOGNITION BY POLYUBIQUITIN-MEDIATED DEGRADATION OF IRF31

    PubMed Central

    Higgs, Rowan; Gabhann, Joan Ní; Larbi, Nadia Ben; Breen, Eamon P.; Fitzgerald, Katherine A.; Jefferies, Caroline A.

    2010-01-01

    Induction of type I interferons is a fundamental cellular response to both viral and bacterial infection. The role of the transcription factor IRF3 is well established in driving this process. However, equally as important are cellular mechanisms for turning off type I interferon production in order to limit this response. In this respect, IRF3 has previously been shown to be targeted for ubiquitin-mediated degradation post-viral detection in order to turn off the IFN-β response. Here we provide evidence that the E3 ligase Ro52 (TRIM21) targets IRF3 for degradation post-pathogen recognition receptor activation. We demonstrate that Ro52 interacts with IRF3 via its C-terminal SPRY domain, resulting in the polyubiquitination and proteasomal degradation of the transcription factor. Ro52-mediated IRF3 degradation significantly inhibits IFN-β promoter activity, an effect that is reversed in the presence of the proteasomal inhibitor MG132. Specific targeting of Ro52 using shRNA rescues IRF3 degradation following polyI:C-stimulation of HEK293T cells, with a subsequent increase in IFN-β production. Additionally, shRNA targeting of murine Ro52 enhances the production of the IRF3-dependent chemokine RANTES following Sendai virus infection of murine fibroblasts. Collectively, this demonstrates a novel role for Ro52 in turning off and thus limiting IRF3-dependent type I interferon production by targeting the transcription factor for polyubiquitination and subsequent proteasomal degradation. PMID:18641315

  7. Major injury induces increased production of interleukin-10 by cells of the immune system with a negative impact on resistance to infection.

    PubMed Central

    Lyons, A; Kelly, J L; Rodrick, M L; Mannick, J A; Lederer, J A

    1997-01-01

    OBJECTIVE: The purpose of this study was to compare the production of interleukin-10 (IL-10) by peripheral blood mononuclear cells (PBMC) from injured patients and control subjects to determine the responsible cell types and to relate IL-10 production to the occurrence of sepsis. A mouse model of burn injury was used to confirm the human findings and to assess the importance of IL-10 in the lowered resistance to infection after injury. SUMMARY BACKGROUND DATA: Severe injury is associated with depressed immune responses. Although IL-10 is known to inhibit several aspects of immune reactivity, the role of IL-10 in postinjury immune suppression remains controversial. METHODS: Peripheral blood mononuclear cells from 14 burn and 12 trauma patients and 16 healthy individuals were studied at serial intervals for IL-10 production stimulated by a T-cell mitogen, phytohemagglutinin, and by bacterial lipopolysaccharide. To determine the source of IL-10, CD4+ and CD8+ lymphocyte subsets were obtained by selective depletion of PBMC with antibody-coated magnetic beads and were stimulated by anti-CD3 antibody to induce IL-10 secretion. In addition, IL-10 production by patients' PBMC in the first 10 days after injury was assessed for correlation with subsequent septic events. Anti-CD3-stimulated IL-10 production also was determined for CD4- and CD8-enriched lymphocyte subsets obtained by antibody and complement depletion of splenocytes harvested from groups of burn and sham burn mice at day 10 after injury, the time of maximal susceptibility to a septic challenge, cecal ligation and puncture (CLP). Finally, to test the importance of IL-10 in immune suppression in vivo, groups of burn and sham burn mice were treated with anti-IL-10 monoclonal antibody or control immunoglobulin G (IgG) on days 1 and 3 postinjury and were observed for survival after CLP on day 10. RESULTS: Patients' PBMC produced significantly more IL-10 than did controls' PBMC 7 to 14 days after injury. Patients' CD

  8. Premature termination of GAT1 transcription explains paradoxical negative correlation between nitrogen-responsive mRNA, but constitutive low-level protein production

    PubMed Central

    Isabelle, Georis; Tate, Jennifer J; Vierendeels, Fabienne; Cooper, Terrance G; Dubois, Evelyne

    2015-01-01

    The first step in executing the genetic program of a cell is production of mRNA. In yeast, almost every gene is transcribed as multiple distinct isoforms, differing at their 5′ and/or 3′ termini. However, the implications and functional significance of the transcriptome-wide diversity of mRNA termini remains largely unexplored. In this paper, we show that the GAT1 gene, encoding a transcriptional activator of nitrogen-responsive catabolic genes, produces a variety of mRNAs differing in their 5′ and 3′ termini. Alternative transcription initiation leads to the constitutive, low level production of 2 full length proteins differing in their N-termini, whereas premature transcriptional termination generates a short, highly nitrogen catabolite repression- (NCR-) sensitive transcript that, as far as we can determine, is not translated under the growth conditions we used, but rather likely protects the cell from excess Gat1. PMID:26259534

  9. Homologues of Neisserial Heme Oxygenase in Gram-Negative Bacteria: Degradation of Heme by the Product of the pigA Gene of Pseudomonas aeruginosa

    PubMed Central

    Ratliff, Melanie; Zhu, Wenming; Deshmukh, Rahul; Wilks, Angela; Stojiljkovic, Igor

    2001-01-01

    The oxidative cleavage of heme to release iron is a mechanism by which some bacterial pathogens can utilize heme as an iron source. The pigA gene of Pseudomonas aeruginosa is shown to encode a heme oxygenase protein, which was identified in the genome sequence by its significant homology (37%) with HemO of Neisseria meningitidis. When the gene encoding the neisserial heme oxygenase, hemO, was replaced with pigA, we demonstrated that pigA could functionally replace hemO and allow for heme utilization by neisseriae. Furthermore, when pigA was disrupted by cassette mutagenesis in P. aeruginosa, heme utilization was defective in iron-poor media supplemented with heme. This defect could be restored both by the addition of exogenous FeSO4, indicating that the mutant did not have a defect in iron metabolism, and by in trans complementation with pigA from a plasmid with an inducible promoter. The PigA protein was purified by ion-exchange chromotography. The UV-visible spectrum of PigA reconstituted with heme showed characteristics previously reported for other bacterial and mammalian heme oxygenases. The heme-PigA complex could be converted to ferric biliverdin in the presence of ascorbate, demonstrating the need for an exogenous reductant. Acidification and high-performance liquid chromatography analysis of the ascorbate reduction products identified a major product of biliverdin IX-β. This differs from the previously characterized heme oxygenases in which biliverdin IX-α is the typical product. We conclude that PigA is a heme oxygenase and may represent a class of these enzymes with novel regiospecificity. PMID:11591684

  10. The Ubiquitin Ligase Synoviolin Up-regulates Amyloid β Production by Targeting a Negative Regulator of γ-Secretase, Rer1, for Degradation*

    PubMed Central

    Tanabe, Chiaki; Maeda, Tomoji; Zou, Kun; Liu, Junjun; Liu, Shuyu; Nakajima, Toshihiro; Komano, Hiroto

    2012-01-01

    Alzheimer's disease is characterized by the deposition of Aβ, which is generated from the amyloid precursor protein through its cleavage by β- and γ-secretases. The γ-secretase complex component nicastrin (NCT) plays significant roles in the assembly and proper trafficking of the γ-secretase complex and in the recognition of amyloid precursor protein. NCT is incorporated into the γ-secretase complex in the endoplasmic reticulum (ER) and glycosylated in the Golgi. In contrast, unassembled NCT is retrieved or retained in the ER by the protein Retention in endoplasmic reticulum 1 (Rer1). We reported previously that synoviolin (Syvn), an E3 ubiquitin ligase, degrades NCT and affects the generation of Aβ. Here, we examined in more detail the effect of Syvn on the generation of Aβ. We found that overexpression of a dominant negative form of Syvn (C307A mutant) and a Syvn-RNAi decreased the generation of Aβ. These results indicate that the ubiquitin ligase activity of Syvn up-regulates the generation of Aβ. We hypothesized, therefore, that Syvn regulates the assembly or localization of the γ-secretase complex by ubiquitinating Rer1, resulting in its subsequent degradation. Our findings that the level of Rer1 was increased in Syvn knockout fibroblasts because of inhibition of its degradation support this hypothesis. Moreover, we found that Rer1 interacts with Syvn in the ER, is ubiquitinated by Syvn, and is then degraded via the proteasome or lysosomal pathways. Finally, we showed that localization of mature NCT to the plasma membrane as well as γ-secretase complex levels are decreased in fibroblasts of Syvn knockout mice. Thus, it is likely that Syvn regulates the assembly of the γ-secretase complex via the degradation of Rer1, which results in the generation of Aβ. PMID:23129766

  11. Negative-ion states

    SciTech Connect

    Compton, R.N.

    1982-01-01

    In this brief review, we discuss some of the properties of atomic and molecular negative ions and their excited states. Experiments involving photon reactions with negative ions and polar dissociation are summarized. 116 references, 14 figures.

  12. Productive HIV-1 infection is enriched in CD4(-)CD8(-) double negative (DN) T cells at pleural sites of dual infection with HIV and Mycobacterium tuberculosis.

    PubMed

    Meng, Qinglai; Canaday, David H; McDonald, David J; Mayanja-Kizza, Harriet; Baseke, Joy; Toossi, Zahra

    2016-01-01

    A higher human immunodeficiency virus 1 (HIV-1) viral load at pleural sites infected with Mycobacterium tuberculosis (MTB) than in peripheral blood has been documented. However, the cellular source of productive HIV infection in HIV-1/MTB-coinfected pleural fluid mononuclear cells (PFMCs) remains unclear. In this study, we observed significant quantities of HIV-1 p24(+) lymphocytes in PFMCs, but not in peripheral blood mononuclear cells (PBMCs). HIV-1 p24(+) lymphocytes were mostly enriched in DN T cells. Intracellular CD4 expression was detectable in HIV-1 p24(+) DN T cells. HIV-1 p24(+) DN T cells showed lower surface expression of human leukocyte antigen (HLA)-ABC and tetherin than did HIV-1 p24(+) CD4 T cells. Upon in vitro infection of PFMC CD4 T cells from TB mono-infected subjects, Nef- and/or Vpu-deleted HIV mutants showed lower generation of HIV-1 p24(+) DN T cells than the wild-type virus. These data indicate that productively HIV-1-infected DN T cells, generated through down-modulation of surface CD4, likely by HIV-1 Nef and Vpu, are the predominant source of HIV-1 at pleural sites of HIV/MTB coinfection. PMID:26497177

  13. Negative ion generator

    DOEpatents

    Stinnett, R.W.

    1984-05-08

    A negative ion generator is formed from a magnetically insulated transmission line having a coating of graphite on the cathode for producing negative ions and a plurality of apertures on the opposed anode for the release of negative ions. Magnetic insulation keeps electrons from flowing from the cathode to the anode. A transverse magnetic field removes electrons which do escape through the apertures from the trajectory of the negative ions. 8 figs.

  14. Negative ion generator

    DOEpatents

    Stinnett, Regan W.

    1984-01-01

    A negative ion generator is formed from a magnetically insulated transmission line having a coating of graphite on the cathode for producing negative ions and a plurality of apertures on the opposed anode for the release of negative ions. Magnetic insulation keeps electrons from flowing from the cathode to the anode. A transverse magnetic field removes electrons which do escape through the apertures from the trajectory of the negative ions.

  15. [Negative symptoms: which antipsychotics?].

    PubMed

    Maurel, M; Belzeaux, R; Adida, M; Azorin, J-M

    2015-12-01

    Treating negative symptoms of schizophrenia is a major issue and a challenge for the functional and social prognosis of the disease, to which they are closely linked. First- and second-generation antipsychotics allow a reduction of all negative symptoms. The hope of acting directly on primary negative symptoms with any antipsychotic is not supported by the literature. However, the effectiveness of first- and second-generation antipsychotics is demonstrated on secondary negative symptoms. PMID:26776390

  16. Sentential Negation in English

    ERIC Educational Resources Information Center

    Mowarin, Macaulay

    2009-01-01

    This paper undertakes a detailed analysis of sentential negation in the English language with Chomsky's Government-Binding theory of Transformational Grammar as theoretical model. It distinguishes between constituent and sentential negation in English. The essay identifies the exact position of Negation phrase in an English clause structure. It…

  17. Global warming can negate the expected CO2 stimulation in photosynthesis and productivity for soybean grown in the Midwestern United States.

    PubMed

    Ruiz-Vera, Ursula M; Siebers, Matthew; Gray, Sharon B; Drag, David W; Rosenthal, David M; Kimball, Bruce A; Ort, Donald R; Bernacchi, Carl J

    2013-05-01

    Extensive evidence shows that increasing carbon dioxide concentration ([CO2]) stimulates, and increasing temperature decreases, both net photosynthetic carbon assimilation (A) and biomass production for C3 plants. However the [CO2]-induced stimulation in A is projected to increase further with warmer temperature. While the influence of increasing temperature and [CO2], independent of each other, on A and biomass production have been widely investigated, the interaction between these two major global changes has not been tested on field-grown crops. Here, the interactive effect of both elevated [CO2] (approximately 585 μmol mol(-1)) and temperature (+3.5°C) on soybean (Glycine max) A, biomass, and yield were tested over two growing seasons in the Temperature by Free-Air CO2 Enrichment experiment at the Soybean Free Air CO2 Enrichment facility. Measurements of A, stomatal conductance, and intercellular [CO2] were collected along with meteorological, water potential, and growth data. Elevated temperatures caused lower A, which was largely attributed to declines in stomatal conductance and intercellular [CO2] and led in turn to lower yields. Increasing both [CO2] and temperature stimulated A relative to elevated [CO2] alone on only two sampling days during 2009 and on no days in 2011. In 2011, the warmer of the two years, there were no observed increases in yield in the elevated temperature plots regardless of whether [CO2] was elevated. All treatments lowered the harvest index for soybean, although the effect of elevated [CO2] in 2011 was not statistically significant. These results provide a better understanding of the physiological responses of soybean to future climate change conditions and suggest that the potential is limited for elevated [CO2] to mitigate the influence of rising temperatures on photosynthesis, growth, and yields of C3 crops. PMID:23512883

  18. Global Warming Can Negate the Expected CO2 Stimulation in Photosynthesis and Productivity for Soybean Grown in the Midwestern United States1[W][OA

    PubMed Central

    Ruiz-Vera, Ursula M.; Siebers, Matthew; Gray, Sharon B.; Drag, David W.; Rosenthal, David M.; Kimball, Bruce A.; Ort, Donald R.; Bernacchi, Carl J.

    2013-01-01

    Extensive evidence shows that increasing carbon dioxide concentration ([CO2]) stimulates, and increasing temperature decreases, both net photosynthetic carbon assimilation (A) and biomass production for C3 plants. However the [CO2]-induced stimulation in A is projected to increase further with warmer temperature. While the influence of increasing temperature and [CO2], independent of each other, on A and biomass production have been widely investigated, the interaction between these two major global changes has not been tested on field-grown crops. Here, the interactive effect of both elevated [CO2] (approximately 585 μmol mol−1) and temperature (+3.5°C) on soybean (Glycine max) A, biomass, and yield were tested over two growing seasons in the Temperature by Free-Air CO2 Enrichment experiment at the Soybean Free Air CO2 Enrichment facility. Measurements of A, stomatal conductance, and intercellular [CO2] were collected along with meteorological, water potential, and growth data. Elevated temperatures caused lower A, which was largely attributed to declines in stomatal conductance and intercellular [CO2] and led in turn to lower yields. Increasing both [CO2] and temperature stimulated A relative to elevated [CO2] alone on only two sampling days during 2009 and on no days in 2011. In 2011, the warmer of the two years, there were no observed increases in yield in the elevated temperature plots regardless of whether [CO2] was elevated. All treatments lowered the harvest index for soybean, although the effect of elevated [CO2] in 2011 was not statistically significant. These results provide a better understanding of the physiological responses of soybean to future climate change conditions and suggest that the potential is limited for elevated [CO2] to mitigate the influence of rising temperatures on photosynthesis, growth, and yields of C3 crops. PMID:23512883

  19. Negative-ion production on carbon materials in hydrogen plasma: influence of the carbon hybridization state and the hydrogen content on H- yield

    NASA Astrophysics Data System (ADS)

    Ahmad, Ahmad; Pardanaud, Cédric; Carrère, Marcel; Layet, Jean-Marc; Gicquel, Alix; Kumar, Pravin; Eon, David; Jaoul, Cédric; Engeln, Richard; Cartry, Gilles

    2014-02-01

    Highly oriented polycrystalline graphite (HOPG), boron-doped diamond (BDD), nanocrystalline diamond, ultra-nanocrystalline diamond and diamond-like carbon surfaces are exposed to low-pressure hydrogen plasma in a 13.56 MHz plasma reactor. Relative yields of surface-produced H- ions due to bombardment of positive ions from the plasma are measured by an energy analyser cum quadrupole mass spectrometer. Irrespective of plasma conditions (0.2 and 2 Pa), HOPG surfaces show the highest yield at room temperature (RT), while at high temperature (HT), the highest yield (˜3-5 times compared to HOPG surface at RT) is observed on BDD surfaces. The shapes of ion distribution functions are compared at RT and HT to demonstrate the mechanism of ion generation at the surface. Raman spectroscopy analyses of the plasma-exposed samples reveal surface modifications influencing H- production yields, while further analyses strongly suggest that the hydrogen content of the material and the sp3/sp2 ratio are the key parameters in driving the surface ionization efficiency of carbon materials under the chosen plasma conditions.

  20. Knockout of the Trpc1 gene reveals that TRPC1 can promote recovery from anaphylaxis by negatively regulating mast-cell TNF-α production

    PubMed Central

    Medic, Nevenka; Desai, Avanti; Olivera, Ana; Abramowitz, Joel; Birnbaumer, Lutz; Beaven, Michael A.; Gilfillan, Alasdair M.; Metcalfe, Dean D.

    2013-01-01

    Antigen-mediated mast cell (MC) degranulation is the critical early event in the induction of allergic reactions. Transient receptor potential channels (TRPC), particularly TRPC1, are thought to contribute to such MC activation. To explore the contribution of TRPC1 in MC-driven allergic reactions, we examined antigen-mediated anaphylaxis in Trpc1−/− and WT mice, and TRPC1 involvement in the activation of MCs derived from the bone marrow (BMMCs) of these mice. In vivo, we observed a similar induction of passive systemic anaphylaxis in the Trpc1−/− mice compared to WT controls. Nevertheless, there was delayed recovery from this response in Trpc1−/− mice. Furthermore, contrary to expectations, Trpc1−/− BMMCs responded to antigen with enhanced calcium signalling but with little defect in degranulation or associated signalling. In contrast, antigen-mediated production of TNF-α, and other cytokines, was enhanced in the Trpc1−/− BMMCs, as were calcium-dependent events required for these responses. Additionally, circulating levels of TNF-α in response to antigen were preferentially elevated in the Trpc1−/− mice, and administration of an anti-TNF-α antibody blocked the delay in recovery from anaphylaxis in these mice. These data thus provide evidence that, in this model, TRPC1 promotes recovery from the anaphylactic response by repressing antigen-mediated TNF-α release from MCs. PMID:23489970

  1. Apoptosis is induced by infectious bursal disease virus replication in productively infected cells as well as in antigen-negative cells in their vicinity.

    PubMed

    Jungmann, A; Nieper, H; Müller, H

    2001-05-01

    The kinetics of infectious bursal disease virus (IBDV) replication and induction of apoptosis were investigated in vitro and in vivo. After infection of chicken embryo (CE) cells with IBDV strain Cu-1, the proportion of apoptotic cells increased from 5.8% at 4 h post-infection (p.i.) to 64.5% at 48 h p.i. The proportion of apoptotic cells correlated with IBDV replication. UV-inactivated IBDV particles did not induce apoptosis. Double labelling revealed that, early after infection, the majority of antigen-expressing cells were not apoptotic; double-labelled cells appeared more frequently at later times. Remarkably, apoptotic cells were frequently located in the vicinity of antigen-expressing cells. This indicated that an apoptosis-inducing factor(s) might be released by cells that replicate IBDV. Since interferon (IFN) production has been demonstrated after IBDV infection, IFN was considered to be one of several factors. However, supernatants of infected CE cells in which virus infectivity had been neutralized were not sufficient to induce apoptosis. Similar results were observed in the infected bursae of Fabricius: early after infection, most of the cells either showed virus antigens or were apoptotic. Again, double-labelled cells appeared more frequently late after infection. This suggests that indirect mechanisms might also be involved in the induction of apoptosis in vivo, contributing to the rapid depletion of cells in the IBDV-infected bursa. PMID:11297685

  2. Negative modulation of nitric oxide production by neurotensin as a putative mechanism of the diuretic action of SR 48692 in rats

    PubMed Central

    Croci, Tiziano; Landi, Marco; Gully, Danielle; Maffrand, Jean-Pierre; Le Fur, Gérard; Manara, Luciano

    1997-01-01

    We investigated the effect of the non-peptide neurotensin (NT) antagonist SR 48692 on renal function in rats and the involvement of nitric oxide (NO) in the diuretic action of this compound.In fed animals, SR 48692 dose-dependently (0.5 to 12.5 mg kg−1, p.o., 0.03 to 1 mg kg−1, i.p. and 0.1 to 1 μg/rat, i.c.v.) increased urine output and urinary excretion of Na+, K+ and Cl− and reduced urine osmolality. The diuretic activity was also evident in water-deprived, fasted animals and in fasted, water-loaded rats.NT (0.1 μg/rat, i.c.v.) had no effect on urine output in fed rats, but reduced the diuretic action of SR 48692 (1 μg/rat, i.c.v.). The opposite result was obtained in fasted, water-loaded animals: NT dose-dependently (0.01 and 0.1 μg/rat, i.c.v.) inhibited diuresis and this effect was significantly inhibited by i.c.v. SR 48692. In this experimental condition, SR 48692 did not further increase the on-going diuresis.The NO synthesis inhibitor Nω-nitro-L-arginine methyl ester (L-NAME; 30 mg kg−1, i.p.) alone had no effect on urine output in fed rats but prevented the diuretic action of i.c.v. or i.p. SR 48692; L-arginine (1 g kg−1, i.p.) but not D-arginine (1 g kg−1, i.p.) restored the SR 48692-dependent increase in diuresis. L-NAME had no effect on furosemide-stimulated diuresis.Systemically administered L-NAME or i.c.v. NT in fasted, water-loaded rats significantly reduced water diuresis but this effect was no longer seen in animals given i.p. L-arginine. Rats receiving i.c.v. NT, whose diuresis was significantly reduced, also excreted less nitrates and nitrites in urine.Increased diuresis after central or systemic administration of SR 48692 to fed rats was paralleled by increased urinary excretion of nitrates and nitrites, this being consistent with peripheral enhancement of NO production after NT-receptor blockade by SR 48692. The increase in diuresis after furosemide also involved an increase of nitrates and nitrites in

  3. Challenges of a negative work load and implications on morale, productivity and quality of service delivered in NHS laboratories in England

    PubMed Central

    Osaro, Erhabor; Chima, Njemanze

    2014-01-01

    The National Health Service (NHS) is a term used to describe the publicly funded healthcare delivery system providing quality healthcare services in the United Kingdom. There are several challenges militating against the effective laboratory service delivery in the NHS in England. Biomedical scientists work in healthcare to diagnose disease and evaluate the effectiveness of treatment through the analysis of body fluids and tissue samples from patients. They provide the “engine room” of modern medicine with 70% of diagnosis based on the laboratory results generated by them. This review involved the search of literature for information on working condition of biomedical scientist in the NHS in England. Laboratory service delivery in the NHS in England faces numerous daunting challenges; staffing levels in the last few years have become dangerously low, less remunerated, relatively less experienced and predominantly band 5's, multidisciplinary rather than specialty based, associated with working more unsocial hours without adequate recovery time, de-banding of staff, high staff turnaround, profit and cost driven rather than quality. These factors has resulted in burn out, low morale, high sickness absences, increased error rate, poor team spirit, diminished productivity and suboptimal laboratory service delivery. There is the urgent need to retract our steps on unpopular policies to ensure that patient care is not compromised by ensuring adequate staffing level and mix, ensuring adequate remuneration of laboratory staff, implementing evidenced-based specialty oriented service, determining the root cause/s for the high staff turnover and implementing corrective action, identifying other potential sources of waste in the system rather than pruning the already dangerously low staffing levels and promoting a quality delivery side by side cost effectiveness. PMID:25182941

  4. Negative Ion Density Fronts

    SciTech Connect

    Igor Kaganovich

    2000-12-18

    Negative ions tend to stratify in electronegative plasmas with hot electrons (electron temperature Te much larger than ion temperature Ti, Te > Ti ). The boundary separating a plasma containing negative ions, and a plasma, without negative ions, is usually thin, so that the negative ion density falls rapidly to zero-forming a negative ion density front. We review theoretical, experimental and numerical results giving the spatio-temporal evolution of negative ion density fronts during plasma ignition, the steady state, and extinction (afterglow). During plasma ignition, negative ion fronts are the result of the break of smooth plasma density profiles during nonlinear convection. In a steady-state plasma, the fronts are boundary layers with steepening of ion density profiles due to nonlinear convection also. But during plasma extinction, the ion fronts are of a completely different nature. Negative ions diffuse freely in the plasma core (no convection), whereas the negative ion front propagates towards the chamber walls with a nearly constant velocity. The concept of fronts turns out to be very effective in analysis of plasma density profile evolution in strongly non-isothermal plasmas.

  5. The addiction to negativity.

    PubMed

    Lane, R C; Hull, J W; Foehrenbach, L M

    1991-01-01

    In this paper, we have described a type of resistance that has attracted increasing psychoanalytic attention in recent years. Patients exposed to intense negativity during early life may develop an addiction to negative experience as adolescents and adults, and this may constitute a central organizing feature of their personality. In almost all patients, however, some moments of negativity may be observed. We have traced the developmental origins of an attachment to negativity, drawing especially on psychoanalytic investigations of preoedipal pathology. Manifestations and derivatives of early negativity include anhedonia, attachment to physical pain, fear of success, masochism, deprivation of self and others, and negative voyeurism. In discussing the dynamic functions of negativity, we place particular emphasis on two motives: the patient's desires for revenge against early objects that have been a source of deprivation and frustration; and the defensive function of negativity in helping to express as well as ward off dangerous wishes to merge with the object. Deviant forms of autoerotism are likely to be used by these patients to deal with the reactivation of early experiences of neglect and rejection. When negativity is used as a defense or method of relating to others it can lead to a severe disruption of the psychotherapeutic relationship. We have reviewed suggestions for the management of extreme negativity in treatment. Resolution of the therapist's countertransference reactions, especially induced feelings of frustration, rage, and helplessness, is crucial. Emphasis also has been placed on the patient's desires for revenge against self and object, and the manner in which these may be understood and eventually resolved. Only when patient and therapist begin to investigate the adaptive functions of extreme negativity can this pathological symptom be resolved and the patient's awareness of self and sense of autonomy be enhanced. PMID:1763149

  6. High-performance liquid chromatography/high-resolution multiple stage tandem mass spectrometry using negative-ion-mode hydroxide-doped electrospray ionization for the characterization of lignin degradation products.

    PubMed

    Owen, Benjamin C; Haupert, Laura J; Jarrell, Tiffany M; Marcum, Christopher L; Parsell, Trenton H; Abu-Omar, Mahdi M; Bozell, Joseph J; Black, Stuart K; Kenttämaa, Hilkka I

    2012-07-17

    In the search for a replacement for fossil fuel and the valuable chemicals currently obtained from crude oil, lignocellulosic biomass has become a promising candidate as an alternative biorenewable source for crude oil. Hence, many research efforts focus on the extraction, degradation, and catalytic transformation of lignin, hemicellulose, and cellulose. Unfortunately, these processes result in the production of very complex mixtures. Further, while methods have been developed for the analysis of mixtures of oligosaccharides, this is not true for the complex mixtures generated upon degradation of lignin. For example, high-performance liquid chromatography/multiple stage tandem mass spectrometry (HPLC/MS(n)), a tool proven to be invaluable in the analysis of complex mixtures derived from many other biopolymers, such as proteins and DNA, has not been implemented for lignin degradation products. In this study, we have developed an HPLC separation method for lignin degradation products that is amenable to negative-ion-mode electrospray ionization (ESI doped with NaOH), the best method identified thus far for ionization of lignin-related model compounds without fragmentation. The separated and ionized compounds are then analyzed by MS(3) experiments to obtain detailed structural information while simultaneously performing high-resolution measurements to determine their elemental compositions in the two parts of a commercial linear quadrupole ion trap/Fourier-transform ion cyclotron resonance mass spectrometer. A lignin degradation product mixture was analyzed using this method, and molecular structures were proposed for some components. This methodology significantly improves the ability to analyze complex product mixtures that result from degraded lignin. PMID:22746183

  7. Evidence of a local negative role for cocaine and amphetamine regulated transcript (CART), inhibins and low molecular weight insulin like growth factor binding proteins in regulation of granulosa cell estradiol production during follicular waves in cattle

    PubMed Central

    Kobayashi, Yasuhiro; Jimenez-Krassel, Fermin; Ireland, James J; Smith, George W

    2006-01-01

    The ability of ovarian follicles to produce large amounts of estradiol is a hallmark of follicle health status. Estradiol producing capacity is lost in ovarian follicles before morphological signs of atresia. A prominent wave like pattern of growth of antral follicles is characteristic of monotocous species such as cattle, horses and humans. While our knowledge of the role of pituitary gonadotropins in support of antral follicle growth and development is well established, the intrinsic factors that suppress estradiol production and may help promote atresia during follicular waves are not well understood. Numerous growth factors and cytokines have been reported to suppress granulosa cell estradiol production in vitro, but the association of expression of many such factors in vivo with follicle health status and their physiological significance are not clear. The purpose of this review is to discuss the in vivo and in vitro evidence supporting a local physiological role for cocaine and amphetamine regulated transcript, inhibins and low molecular weight insulin like growth factor binding proteins in negative regulation of granulosa cell estradiol production, with emphasis on evidence from the bovine model system. PMID:16611367

  8. The Evolution of Negation.

    ERIC Educational Resources Information Center

    Croft, William

    1991-01-01

    Discusses a method for extrapolation of diachronic processes from synchronic states, the dynamicization of synchronic typologies, to propose a hitherto unobserved historical source for markers of verbal negation, namely irregular negative existential predicate forms. Explanations are proposed for the occurrence of the attested processes in this…

  9. Learning from Negative Morality.

    ERIC Educational Resources Information Center

    Oser, Fritz K.

    1996-01-01

    Identifies and discusses the elements and applications of learning from negative morality. Negative morality refers to the experience of learning from mistakes thereby creating a body of personal knowledge about "what not to do." This knowledge not only protects individuals but steers them to the right behavior. (MJP)

  10. On Negative Mass

    NASA Astrophysics Data System (ADS)

    Belletête, Jonathan; Paranjape, M. B.

    2013-06-01

    The Schwarzschild solution to the matter free, spherically symmetric Einstein equations has one free parameter, the mass. But the mass can be of any sign. What is the meaning of the negative mass solutions? The answer to this question for the case of a pure Schwarzschild negative mass black solution is still elusive, however, in this essay, we will consider negative mass solutions within a Schwarzschild-de Sitter geometry. We show that there exist reasonable configurations of matter, bubbles of distributions of matter, that satisfy the dominant energy condition everywhere, that are nonsingular and well behaved everywhere, but correspond to the negative mass Schwarzschild-de Sitter geometry outside the matter distribution. These negative mass bubbles could occur as the end state of a quantum tunneling transition.

  11. An advanced negative hydrogen ion source.

    PubMed

    Goncharov, Alexey A; Dobrovolsky, Andrey N; Goretskii, Victor P

    2016-02-01

    The results of investigation of emission productivity of negative particles source with cesiated combined discharge are presented. A cylindrical beam of negative hydrogen ions with density about 2 A/cm(2) in low noise mode on source emission aperture is obtained. The total beam current values are up to 200 mA for negative hydrogen ions and up to 1.5 A for all negative particles with high divergence after source. The source has simple design and can produce stable discharge with low level of oscillation. PMID:26931996

  12. Kriging without negative weights

    SciTech Connect

    Szidarovszky, F.; Baafi, E.Y.; Kim, Y.C.

    1987-08-01

    Under a constant drift, the linear kriging estimator is considered as a weighted average of n available sample values. Kriging weights are determined such that the estimator is unbiased and optimal. To meet these requirements, negative kriging weights are sometimes found. Use of negative weights can produce negative block grades, which makes no practical sense. In some applications, all kriging weights may be required to be nonnegative. In this paper, a derivation of a set of nonlinear equations with the nonnegative constraint is presented. A numerical algorithm also is developed for the solution of the new set of kriging equations.

  13. Negative birefringent polyimide films

    NASA Technical Reports Server (NTRS)

    Harris, Frank W. (Inventor); Cheng, Stephen Z. D. (Inventor)

    1994-01-01

    A negative birefringent film, useful in liquid crystal displays, and a method for controlling the negative birefringence of a polyimide film is disclosed which allows the matching of an application to a targeted amount of birefringence by controlling the degree of in-plane orientation of the polyimide by the selection of functional groups within both the diamine and dianhydride segments of the polyimide which affect the polyimide backbone chain rigidity, linearity, and symmetry. The higher the rigidity, linearity and symmetry of the polyimide backbone, the larger the value of the negative birefringence of the polyimide film.

  14. Negative Ion Beam Extraction and Emittance

    SciTech Connect

    Holmes, Andrew J. T.

    2007-08-10

    The use of magnetic fields to both aid the production of negative ions and suppress the co-extracted electrons causes the emittance and hence the divergence of the negative ion beam to increase significantly due to the plasma non-uniformity from jxB drift. This drift distorts the beam-plasma meniscus and experimental results of the beam emittance are presented, which show that non-uniformity causes the square of the emittance to be proportional to the 2/3 power of the extracted current density. This can cause the divergence of the negative ion beam to be significantly larger than its positive ion counterpart. By comparing results from positive and negative ion beam emittances from the same source, it is also possible to draw conclusions about their vulnerability to magnetic effects. Finally emittances of caesiated and un-caesiated negative ion beams are compared to show how the surface and volume modes of production interact.

  15. Negative electrode composition

    DOEpatents

    Kaun, Thomas D.; Chilenskas, Albert A.

    1982-01-01

    A secondary electrochemical cell and a negative electrode composition for use therewith comprising a positive electrode containing an active material of a chalcogen or a transiton metal chalcogenide, a negative electrode containing a lithium-aluminum alloy and an amount of a ternary alloy sufficient to provide at least about 5 percent overcharge capacity relative to a negative electrode solely of the lithium-aluminum alloy, the ternary alloy comprising lithium, aluminum, and iron or cobalt, and an electrolyte containing lithium ions in contact with both of the positive and the negative electrodes. The ternary alloy is present in the electrode in the range of from about 5 percent to about 50 percent by weight of the electrode composition and may include lithium-aluminum-nickel alloy in combination with either the ternary iron or cobalt alloys. A plurality of series connected cells having overcharge capacity can be equalized on the discharge side without expensive electrical equipment.

  16. Logo and Negative Numbers.

    ERIC Educational Resources Information Center

    Strawn, Candace A.

    1998-01-01

    Describes LOGO's turtle graphics capabilities based on a sixth-grade classroom's activities with negative numbers and Logo programming. A sidebar explains LOGO and offers suggestions to teachers for using LOGO effectively. (LRW)

  17. Atomic negative ions

    SciTech Connect

    Brage, T.

    1991-01-01

    We review some of the recent progress in the studies of alkaline-earth, negative ions. Computations of autodetachment rates, electron affinities and transition wavelengths are discussed and some new and improved results are given.

  18. Atomic negative ions

    SciTech Connect

    Brage, T.

    1991-12-31

    We review some of the recent progress in the studies of alkaline-earth, negative ions. Computations of autodetachment rates, electron affinities and transition wavelengths are discussed and some new and improved results are given.

  19. Negative affixes in medical English.

    PubMed

    Dzuganova, B

    2006-01-01

    Many medical terms have negative meaning expressed by means of a negative prefix or suffix. The most frequently used negative prefixes are: a-, dis-, in-, non-, and un-. There is only one negative suffix -less (Ref. 15). PMID:17125069

  20. Brand Suicide? Memory and Liking of Negative Brand Names.

    PubMed

    Guest, Duncan; Estes, Zachary; Gibbert, Michael; Mazursky, David

    2016-01-01

    Negative brand names are surprisingly common in the marketplace (e.g., Poison perfume; Hell pizza, and Monster energy drink), yet their effects on consumer behavior are currently unknown. Three studies investigated the effects of negative brand name valence on brand name memory and liking of a branded product. Study 1 demonstrates that relative to non-negative brand names, negative brand names and their associated logos are better recognised. Studies 2 and 3 demonstrate that negative valence of a brand name tends to have a detrimental influence on product evaluation with evaluations worsening as negative valence increases. However, evaluation is also dependent on brand name arousal, with high arousal brand names resulting in more positive evaluations, such that moderately negative brand names are equally as attractive as some non-negative brand names. Study 3 shows evidence for affective habituation, whereby the effects of negative valence reduce with repeated exposures to some classes of negative brand name. PMID:27023872

  1. Brand Suicide? Memory and Liking of Negative Brand Names

    PubMed Central

    Guest, Duncan; Estes, Zachary; Gibbert, Michael; Mazursky, David

    2016-01-01

    Negative brand names are surprisingly common in the marketplace (e.g., Poison perfume; Hell pizza, and Monster energy drink), yet their effects on consumer behavior are currently unknown. Three studies investigated the effects of negative brand name valence on brand name memory and liking of a branded product. Study 1 demonstrates that relative to non-negative brand names, negative brand names and their associated logos are better recognised. Studies 2 and 3 demonstrate that negative valence of a brand name tends to have a detrimental influence on product evaluation with evaluations worsening as negative valence increases. However, evaluation is also dependent on brand name arousal, with high arousal brand names resulting in more positive evaluations, such that moderately negative brand names are equally as attractive as some non-negative brand names. Study 3 shows evidence for affective habituation, whereby the effects of negative valence reduce with repeated exposures to some classes of negative brand name. PMID:27023872

  2. Negative pressure wound therapy.

    PubMed

    Thompson, James T; Marks, Malcolm W

    2007-10-01

    Negative pressure wound therapy has become an increasingly important part of wound management. Over the last decade, numerous uses for this method of wound management have been reported, ranging from acute and chronic wounds, to closure of open sternal and abdominal wounds, to assistance with skin grafts. The biophysics behind the success of this treatment largely have focused on increased wound blood flow, increased granulation tissue formation, decreased bacterial counts, and stimulation of wound healing pathways through shear stress mechanisms. The overall success of negative pressure wound therapy has led to a multitude of clinical applications, which are discussed in this article. PMID:17967622

  3. The Negative Repetition Effect

    ERIC Educational Resources Information Center

    Mulligan, Neil W.; Peterson, Daniel J.

    2013-01-01

    A fundamental property of human memory is that repetition enhances memory. Peterson and Mulligan (2012) recently documented a surprising "negative repetition effect," in which participants who studied a list of cue-target pairs twice recalled fewer targets than a group who studied the pairs only once. Words within a pair rhymed, and…

  4. [Chemotherapies of negative schizophrenia].

    PubMed

    Petit, M; Dollfus, S

    1991-01-01

    Five years ago, Goldberg claimed that negative symptoms of schizophrenia do respond to neuroleptics. This apparent discovery is, in fact, a very common way of thinking for European schools of psychiatry, specially the French one guided by Delay and Deniker. Initially focused on reserpine and some alerting phenothiazines such as thioproperazine, this opinion has been extended to benzamides in the 1970s. The analysis of the publications devoted to this point indicates that several drugs are actually considered as potent disinhibitors (i.e. active on negative symptoms of schizophrenia): Phenothiazines: As shown in the controlled studies by Itil (1971), Poirier-Littré (1988), fluphenazine and pipotiazine improve the BPRS anergia factor and the SANS score. Butyrophenones: The first description of the "imipramine like" effect of trifluperidol by Janssen (1959) initiated the studies by Gallant (1960), Fox (1963). They compared trifluperidol at low doses versus haloperidol and chlorpromazine at medium and high doses, BPRS anergia factor improved only at low doses. Diphenylbutylpiperidines (DPBP): Meltzer's review (1986) concluded to the efficacy of such drugs on negative symptoms appearing as a specific biochemical relationship effect. A definite analysis about doses leads to a very different interpretation: DPBP low doses and only low doses improved negative symptoms as much as some low doses of phenothiazines. On the opposite, DPBP, phenothiazines and butyrophenones high doses are inefficient.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1683624

  5. Disentangling theorem and monogamy for entanglement negativity

    NASA Astrophysics Data System (ADS)

    He, Huan; Vidal, Guifre

    2015-01-01

    Entanglement negativity is a measure of mixed-state entanglement increasingly used to investigate and characterize emerging quantum many-body phenomena, including quantum criticality and topological order. We present two results for the entanglement negativity: a disentangling theorem, which allows the use of this entanglement measure as a means to detect whether a wave function of three subsystems A ,B , and C factorizes into a product state for parts A B1 and B2C ; and a monogamy relation conjecture based on entanglement negativity, which states that if A is very entangled with B , then A cannot be simultaneously very entangled also with C .

  6. Negative refraction and superconductivity

    NASA Astrophysics Data System (ADS)

    Amariti, Antonio; Forcella, Davide; Mariotti, Alberto; Siani, Massimo

    2011-10-01

    We discuss exotic properties of charged hydrodynamical systems, in the broken superconducting phase, probed by electromagnetic waves. Motivated by general arguments from hydrodynamics, we observe that negative refraction, namely the propagation in opposite directions of the phase velocities and of the energy flux, is expected for low enough frequencies. We corroborate this general idea by analyzing a holographic superconductor in the AdS/CFT correspondence, where the response functions can be explicitly computed. We study the dual gravitational theory both in the probe and in the backreacted case. We find that, while in the first case the refractive index is positive at every frequency, in the second case there is negative refraction at low enough frequencies. This is in agreement with hydrodynamic considerations.

  7. Think (Gram) negative!

    PubMed Central

    2010-01-01

    The increasing prevalence of multiresistant Gram-negative bacteria of the Enterobacteriaceae family in Europe is a worrisome phenomenon. Extended spectrum betalactamase-producing Escherichia coli strains are widespread in the community and are frequently imported into the hospital. Of even more concern is the spread of carbapenem-resistant strains of Klebsiella spp. from regions where they are already endemic. Antibiotic use is a main driver of antibiotic resistance, which again increases broad spectrum antibiotic use, resulting in a vicious circle that is difficult to interrupt. The present commentary highlights important findings of a surveillance study of antimicrobial use and resistance in German ICUs over 8 years with a focus on Gram-negative resistance. PMID:20587087

  8. The negative repetition effect.

    PubMed

    Mulligan, Neil W; Peterson, Daniel J

    2013-09-01

    A fundamental property of human memory is that repetition enhances memory. Peterson and Mulligan (2012) recently documented a surprising negative repetition effect, in which participants who studied a list of cue-target pairs twice recalled fewer targets than a group who studied the pairs only once. Words within a pair rhymed, and across pairs, the target words were drawn from a small set of categories. In the repetition condition, the pairs were initially presented in a random order and then presented a 2nd time blocked by the category of the target words. In the single presentation condition, the pairs were presented only in the blocked order. Participants in the former condition recalled fewer target words on a free recall test despite having seen the word pairs twice (the negative repetition effect). This phenomenon is explored in a series of 5 experiments assessing 3 theoretical accounts of the effect. The experiments demonstrate that the negative repetition effect generalizes over multiple encoding conditions (reading and generative encoding), over different memory tests (free and cued recall), and over delay (5 min and 2 days). The results argue against a retrieval account and a levels-of-processing account but are consistent with the item-specific-relational account, the account upon which the effect was initially predicated. PMID:23421508

  9. Negative Sentences in Children with Specific Language Impairment

    ERIC Educational Resources Information Center

    Thornton, Rosalind; Rombough, Kelly; Martin, Jasmine; Orton, Linda

    2016-01-01

    This study used elicited production methodology to investigate the negative sentences that are produced by English-speaking children with specific language impairment (SLI). Negative sentences were elicited in contexts in which adults use the negative auxiliary verb doesn't (e.g., "It doesn't fit"). This form was targeted to see how…

  10. Negative Entropy of Life

    NASA Astrophysics Data System (ADS)

    Goradia, Shantilal

    2015-10-01

    We modify Newtonian gravity to probabilistic quantum mechanical gravity to derive strong coupling. If this approach is valid, we should be able to extend it to the physical body (life) as follows. Using Boltzmann equation, we get the entropy of the universe (137) as if its reciprocal, the fine structure constant (ALPHA), is the hidden candidate representing the negative entropy of the universe which is indicative of the binary information as its basis (http://www.arXiv.org/pdf/physics0210040v5). Since ALPHA relates to cosmology, it must relate to molecular biology too, with the binary system as the fundamental source of information for the nucleotides of the DNA as implicit in the book by the author: ``Quantum Consciousness - The Road to Reality.'' We debate claims of anthropic principle based on the negligible variation of ALPHA and throw light on thermodynamics. We question constancy of G in multiple ways.

  11. Negative Optical Torque

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Ng, Jack; Ding, Kun; Fung, Kin Hung; Lin, Zhifang; Chan, C. T.

    2014-09-01

    Light carries angular momentum, and as such it can exert torques on material objects. Applications of these opto-mechanical effects were limited initially due to their smallness in magnitude, but later becomes powerful and versatile after the invention of laser. Novel and practical approaches for harvesting light for particle rotation have since been demonstrated, where the structure is always subjected to a positive optical torque along a certain axis if the incident angular momentum has a positive projection on the same axis. We report here an interesting phenomenon of ``negative optical torque'', meaning that incoming photons carrying angular momentum rotate an object in the opposite sense. Surprisingly this can be realized quite straightforwardly in simple planar structures. Field retardation is a necessary condition and discrete rotational symmetry of material object plays an important role. The optimal conditions are explored and explained.

  12. Negative ion source

    DOEpatents

    Leung, K.N.; Ehlers, K.W.

    1982-08-06

    An ionization vessel is divided into an ionizing zone and an extraction zone by a magnetic filter. The magnetic filter prevents high-energy electrons from crossing from the ionizing zone to the extraction zone. A small positive voltage impressed on a plasma grid, located adjacent an extraction grid, positively biases the plasma in the extraction zone to thereby prevent positive ions from migrating from the ionizing zone to the extraction zone. Low-energy electrons, which would ordinarily be dragged by the positive ions into the extraction zone, are thereby prevented from being present in the extraction zone and being extracted along with negative ions by the extraction grid. Additional electrons are suppressed from the output flux using ExB drift provided by permanent magnets and the extractor grid electrical field.

  13. Negative ion source

    DOEpatents

    Leung, K.N.; Ehlers, K.W.

    1984-12-04

    An ionization vessel is divided into an ionizing zone and an extraction zone by a magnetic filter. The magnetic filter prevents high-energy electrons from crossing from the ionizing zone to the extraction zone. A small positive voltage impressed on a plasma grid, located adjacent an extraction grid, positively biases the plasma in the extraction zone to thereby prevent positive ions from migrating from the ionizing zone to the extraction zone. Low-energy electrons, which would ordinarily be dragged by the positive ions into the extraction zone, are thereby prevented from being present in the extraction zone and being extracted along with negative ions by the extraction grid. Additional electrons are suppressed from the output flux using ExB drift provided by permanent magnets and the extractor grid electrical field. 14 figs.

  14. Negative ion source

    DOEpatents

    Leung, Ka-Ngo; Ehlers, Kenneth W.

    1984-01-01

    An ionization vessel is divided into an ionizing zone and an extraction zone by a magnetic filter. The magnetic filter prevents high-energy electrons from crossing from the ionizing zone to the extraction zone. A small positive voltage impressed on a plasma grid, located adjacent an extraction grid, positively biases the plasma in the extraction zone to thereby prevent positive ions from migrating from the ionizing zone to the extraction zone. Low-energy electrons, which would ordinarily be dragged by the positive ions into the extraction zone, are thereby prevented from being present in the extraction zone and being extracted along with negative ions by the extraction grid. Additional electrons are suppressed from the output flux using ExB drift provided by permanent magnets and the extractor grid electrical field.

  15. Negative Optical Torque

    PubMed Central

    Chen, Jun; Ng, Jack; Ding, Kun; Fung, Kin Hung; Lin, Zhifang; Chan, C. T.

    2014-01-01

    Light carries angular momentum, and as such it can exert torques on material objects. Applications of these opto-mechanical effects were limited initially due to their smallness in magnitude, but later becomes powerful and versatile after the invention of laser. Novel and practical approaches for harvesting light for particle rotation have since been demonstrated, where the structure is always subjected to a positive optical torque along a certain axis if the incident angular momentum has a positive projection on the same axis. We report here an interesting phenomenon of “negative optical torque”, meaning that incoming photons carrying angular momentum rotate an object in the opposite sense. Surprisingly this can be realized quite straightforwardly in simple planar structures. Field retardation is a necessary condition and discrete rotational symmetry of material object plays an important role. The optimal conditions are explored and explained. PMID:25226863

  16. Do `negative' temperatures exist?

    NASA Astrophysics Data System (ADS)

    Lavenda, B. H.

    1999-06-01

    A modification of the second law is required for a system with a bounded density of states and not the introduction of a `negative' temperature scale. The ascending and descending branches of the entropy versus energy curve describe particle and hole states, having thermal equations of state that are given by the Fermi and logistic distributions, respectively. Conservation of energy requires isentropic states to be isothermal. The effect of adiabatically reversing the field is entirely mechanical because the only difference between the two states is their energies. The laws of large and small numbers, leading to the normal and Poisson approximations, characterize statistically the states of infinite and zero temperatures, respectively. Since the heat capacity also vanishes in the state of maximum disorder, the third law can be generalized in systems with a bounded density of states: the entropy tends to a constant as the temperature tends to either zero or infinity.

  17. Color infrared film as a negative material

    USGS Publications Warehouse

    Pease, Robert W.

    1970-01-01

    Original problems encountered in endeavors to use color infraredfilm as a negative material have been overcome by a simple modification in processing. This makes more feasible the production of infrared color prints for field use and yields an infrared counterpart to Aero-Neg.

  18. 19. Print from copy negative (original glass plate negative in ...

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

    19. Print from copy negative (original glass plate negative in Tippecanoe County Historical Society.) Original photo dated May 7, 1893. View north, south side. - Big Four Depot, 10 South Second Street, Lafayette, Tippecanoe County, IN

  19. Negative Expertise: Comparing Differently Tenured Elder Care Nurses' Negative Knowledge

    ERIC Educational Resources Information Center

    Gartmeier, Martin; Lehtinen, Erno; Gruber, Hans; Heid, Helmut

    2011-01-01

    Negative expertise is conceptualised as the professional's ability to avoid errors during practice due to certain cognitive agencies. In this study, negative knowledge (i.e. knowledge about what is wrong in a certain context and situation) is conceptualised as one such agency. This study compares and investigates the negative knowledge of elder…

  20. Coagulase-Negative Staphylococci

    PubMed Central

    Heilmann, Christine; Peters, Georg

    2014-01-01

    SUMMARY The definition of the heterogeneous group of coagulase-negative staphylococci (CoNS) is still based on diagnostic procedures that fulfill the clinical need to differentiate between Staphylococcus aureus and those staphylococci classified historically as being less or nonpathogenic. Due to patient- and procedure-related changes, CoNS now represent one of the major nosocomial pathogens, with S. epidermidis and S. haemolyticus being the most significant species. They account substantially for foreign body-related infections and infections in preterm newborns. While S. saprophyticus has been associated with acute urethritis, S. lugdunensis has a unique status, in some aspects resembling S. aureus in causing infectious endocarditis. In addition to CoNS found as food-associated saprophytes, many other CoNS species colonize the skin and mucous membranes of humans and animals and are less frequently involved in clinically manifested infections. This blurred gradation in terms of pathogenicity is reflected by species- and strain-specific virulence factors and the development of different host-defending strategies. Clearly, CoNS possess fewer virulence properties than S. aureus, with a respectively different disease spectrum. In this regard, host susceptibility is much more important. Therapeutically, CoNS are challenging due to the large proportion of methicillin-resistant strains and increasing numbers of isolates with less susceptibility to glycopeptides. PMID:25278577

  1. Improved negative ion source

    DOEpatents

    Delmore, J.E.

    1984-05-01

    A method and apparatus for providing a negative ion source accelerates electrons away from a hot filament electron emitter into a region of crossed electric and magnetic fields arranged in a magnetron configuration. During a portion of the resulting cycloidal path, the electron velocity is reduced below its initial value. The electron accelerates as it leaves the surface at a rate of only slightly less than if there were no magnetic field, thereby preventing a charge buildup at the surface of the emitter. As the electron traverses the cycloid, it is decelerated during the second, third, and fourth quadrants, then reaccelerated as it approaches the end of the fourth quadrant to regain its original velocity. The minimum velocity occurs during the fourth quadrant, and corresponds to an electron temperature of 200 to 500/sup 0/C for the electric and magnetic fields commonly encountered in the ion sources of magnetic sector mass spectrometers. An ion source using the above-described thermalized electrons is also disclosed.

  2. Plasmonics without negative dielectrics

    NASA Astrophysics Data System (ADS)

    Della Giovampaola, Cristian; Engheta, Nader

    2016-05-01

    Plasmonic phenomena are exhibited in light-matter interaction involving materials whose real parts of permittivity functions attain negative values at operating wavelengths. However, such materials usually suffer from dissipative losses, thus limiting the performance of plasmon-based optical devices. Here, we utilize an alternative methodology that mimics a variety of plasmonic phenomena by exploiting the well-known structural dispersion of electromagnetic modes in bounded guided-wave structures filled with only materials with positive permittivity. A key issue in the design of such structures is prevention of mode coupling, which can be achieved by implementing thin metallic wires at proper interfaces. This method, which is more suitable for lower frequencies, allows designers to employ conventional dielectrics and highly conductive metals for which the loss is low at these frequencies, while achieving plasmonic features. We demonstrate, numerically and analytically, that this platform can provide surface plasmon polaritons, local plasmonic resonance, plasmonic cloaking, and epsilon-near-zero-based tunneling using conventional positive-dielectric materials.

  3. Coagulase-negative staphylococci.

    PubMed

    Becker, Karsten; Heilmann, Christine; Peters, Georg

    2014-10-01

    The definition of the heterogeneous group of coagulase-negative staphylococci (CoNS) is still based on diagnostic procedures that fulfill the clinical need to differentiate between Staphylococcus aureus and those staphylococci classified historically as being less or nonpathogenic. Due to patient- and procedure-related changes, CoNS now represent one of the major nosocomial pathogens, with S. epidermidis and S. haemolyticus being the most significant species. They account substantially for foreign body-related infections and infections in preterm newborns. While S. saprophyticus has been associated with acute urethritis, S. lugdunensis has a unique status, in some aspects resembling S. aureus in causing infectious endocarditis. In addition to CoNS found as food-associated saprophytes, many other CoNS species colonize the skin and mucous membranes of humans and animals and are less frequently involved in clinically manifested infections. This blurred gradation in terms of pathogenicity is reflected by species- and strain-specific virulence factors and the development of different host-defending strategies. Clearly, CoNS possess fewer virulence properties than S. aureus, with a respectively different disease spectrum. In this regard, host susceptibility is much more important. Therapeutically, CoNS are challenging due to the large proportion of methicillin-resistant strains and increasing numbers of isolates with less susceptibility to glycopeptides. PMID:25278577

  4. Negative Pressure Wound Therapy

    PubMed Central

    2006-01-01

    Executive Summary Objective This review was conducted to assess the effectiveness of negative pressure wound therapy. Clinical Need: Target Population and Condition Many wounds are difficult to heal, despite medical and nursing care. They may result from complications of an underlying disease, like diabetes; or from surgery, constant pressure, trauma, or burns. Chronic wounds are more often found in elderly people and in those with immunologic or chronic diseases. Chronic wounds may lead to impaired quality of life and functioning, to amputation, or even to death. The prevalence of chronic ulcers is difficult to ascertain. It varies by condition and complications due to the condition that caused the ulcer. There are, however, some data on condition-specific prevalence rates; for example, of patients with diabetes, 15% are thought to have foot ulcers at some time during their lives. The approximate community care cost of treating leg ulcers in Canada, without reference to cause, has been estimated at upward of $100 million per year. Surgically created wounds can also become chronic, especially if they become infected. For example, the reported incidence of sternal wound infections after median sternotomy is 1% to 5%. Abdominal surgery also creates large open wounds. Because it is sometimes necessary to leave these wounds open and allow them to heal on their own (secondary intention), some may become infected and be difficult to heal. Yet, little is known about the wound healing process, and this makes treating wounds challenging. Many types of interventions are used to treat wounds. Current best practice for the treatment of ulcers and other chronic wounds includes debridement (the removal of dead or contaminated tissue), which can be surgical, mechanical, or chemical; bacterial balance; and moisture balance. Treating the cause, ensuring good nutrition, and preventing primary infection also help wounds to heal. Saline or wet-to-moist dressings are reported as

  5. Conservatives, liberals, and "the negative".

    PubMed

    Charney, Evan

    2014-06-01

    The authors connect conservatism with aversion to negativity via the tendentious use of the language of threats to characterize conservatism, but not liberalism. Their reliance upon an objective conception of the negative ignores the fact that much of the disagreement between liberals and conservatives is over whether or not one and the same state of affairs is negative or positive. PMID:24970432

  6. Negativity bias and basic values.

    PubMed

    Schwartz, Shalom H

    2014-06-01

    Basic values explain more variance in political attitudes and preferences than other personality and sociodemographic variables. The values most relevant to the political domain are those likely to reflect the degree of negativity bias. Value conflicts that represent negativity bias clarify differences between what worries conservatives and liberals and suggest that relations between ideology and negativity bias are linear. PMID:24970450

  7. A new bivariate negative binomial regression model

    NASA Astrophysics Data System (ADS)

    Faroughi, Pouya; Ismail, Noriszura

    2014-12-01

    This paper introduces a new form of bivariate negative binomial (BNB-1) regression which can be fitted to bivariate and correlated count data with covariates. The BNB regression discussed in this study can be fitted to bivariate and overdispersed count data with positive, zero or negative correlations. The joint p.m.f. of the BNB1 distribution is derived from the product of two negative binomial marginals with a multiplicative factor parameter. Several testing methods were used to check overdispersion and goodness-of-fit of the model. Application of BNB-1 regression is illustrated on Malaysian motor insurance dataset. The results indicated that BNB-1 regression has better fit than bivariate Poisson and BNB-2 models with regards to Akaike information criterion.

  8. Negative-ion source applications.

    PubMed

    Ishikawa, J

    2008-02-01

    In this paper heavy negative-ion sources which we developed and their applications for materials science are reviewed. Heavy negative ions can be effectively produced by the ejection of a sputtered atom through the optimally cesiated surface of target with a low work function. Then, enough continuous negative-ion currents for materials-science applications can be obtained. We developed several kinds of sputter-type heavy negative-ion sources such as neutral- and ionized-alkaline metal bombardment-type heavy negative-ion source and rf-plasma sputter type. In the case where a negative ion is irradiated on a material surface, surface charging seldom takes place because incoming negative charge of the negative ion is well balanced with outgoing negative charge of the released secondary electron. In the negative-ion implantation into an insulator or insulated conductive material, high precision implantation processing with charge-up free properties can be achieved. Negative-ion implantation technique, therefore, can be applied to the following novel material processing systems: the surface modification of micrometer-sized powders, the nanoparticle formation in an insulator for the quantum devices, and the nerve cell growth manipulation by precise control of the biocompatibility of polymer surface. When a negative ion with low kinetic energy approaches the solid surface, the kinetic energy causes the interatomic bonding (kinetic bonding), and formation of a metastable material is promoted. Carbon films with high constituent of sp(3) bonding, therefore, can be formed by carbon negative-ion beam deposition. PMID:18315249

  9. Turning negative into positive: public health mass media campaigns and negative advertising

    PubMed Central

    Apollonio, D. E.; Malone, R. E.

    2009-01-01

    Literature suggests that ‘negative advertising’ is an effective way to encourage behavioral changes, but it has enjoyed limited use in public health media campaigns. However, as public health increasingly focuses on non-communicable disease prevention, negative advertising could be more widely applied. This analysis considers an illustrative case from tobacco control. Relying on internal tobacco industry documents, surveys and experimental data and drawing from political advocacy literature, we describe tobacco industry and public health research on the American Legacy Foundation’s “truth” campaign, an example of effective negative advertising in the service of public health. The tobacco industry determined that the most effective advertisements run by Legacy’s “truth” campaign were negative advertisements. Although the tobacco industry’s own research suggested that these negative ads identified and effectively reframed the cigarette as a harmful consumer product rather than focusing solely on tobacco companies, Philip Morris accused Legacy of ‘vilifying’ it. Public health researchers have demonstrated the effectiveness of the “truth” campaign in reducing smoking initiation. Research on political advocacy demonstrating the value of negative advertising has rarely been used in the development of public health media campaigns, but negative advertising can effectively communicate certain public health messages and serve to counter corporate disease promotion. PMID:18948569

  10. 24. Duplicate negative of an historic negative. 'AERIAL VIEW OF ...

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

    24. Duplicate negative of an historic negative. 'AERIAL VIEW OF AREA 'B' HOLSTON ORDNANCE WORKS.' 1944. #OCMH 4-12.2ASAV3 in Super Explosives Program RDX and Its Composition A, B, & C, Record Group No. 319, National Archives, Washington, D.C. - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  11. Negative cooperativity in regulatory enzymes.

    PubMed

    Levitzki, A; Koshland, D E

    1969-04-01

    Negative cooperativity has been observed in CTP synthetase, an allosteric enzyme which contains a regulatory site. Thus, the same enzyme exhibits negative cooperativity for GTP (an effector) and glutamine (a substrate) and positive cooperativity for ATP and UTP (both substrates). In the process of the delineation of these phenomena, diagnostic procedures for negative cooperativity were developed. Application of these procedures to other enzymes indicates that negative cooperativity is a characteristic of many of them. These findings add strong support for the sequential model of subunit interactions which postulates that ligand-induced conformational changes are responsible for regulatory and cooperative phenomena in enzymes. PMID:5256410

  12. Negative ions of polyatomic molecules.

    PubMed Central

    Christophorou, L G

    1980-01-01

    In this paper general concepts relating to, and recent advances in, the study of negative ions of polyatomic molecules area discussed with emphasis on halocarbons. The topics dealt with in the paper are as follows: basic electron attachment processes, modes of electron capture by molecules, short-lived transient negative ions, dissociative electron attachment to ground-state molecules and to "hot" molecules (effects of temperature on electron attachment), parent negative ions, effect of density, nature, and state of the medium on electron attachment, electron attachment to electronically excited molecules, the binding of attached electrons to molecules ("electron affinity"), and the basic and the applied significance of negative-ion studies. PMID:7428744

  13. Intrinsic Negative Mass from Nonlinearity

    NASA Astrophysics Data System (ADS)

    Di Mei, F.; Caramazza, P.; Pierangeli, D.; Di Domenico, G.; Ilan, H.; Agranat, A. J.; Di Porto, P.; DelRe, E.

    2016-04-01

    We propose and provide experimental evidence of a mechanism able to support negative intrinsic effective mass. The idea is to use a shape-sensitive nonlinearity to change the sign of the mass in the leading linear propagation equation. Intrinsic negative-mass dynamics is reported for light beams in a ferroelectric crystal substrate, where the diffusive photorefractive nonlinearity leads to a negative-mass Schrödinger equation. The signature of inverted dynamics is the observation of beams repelled from strongly guiding integrated waveguides irrespective of wavelength and intensity and suggests shape-sensitive nonlinearity as a basic mechanism leading to intrinsic negative mass.

  14. Neurobiological background of negative symptoms.

    PubMed

    Galderisi, Silvana; Merlotti, Eleonora; Mucci, Armida

    2015-10-01

    Studies investigating neurobiological bases of negative symptoms of schizophrenia failed to provide consistent findings, possibly due to the heterogeneity of this psychopathological construct. We tried to review the findings published to date investigating neurobiological abnormalities after reducing the heterogeneity of the negative symptoms construct. The literature in electronic databases as well as citations and major articles are reviewed with respect to the phenomenology, pathology, genetics and neurobiology of schizophrenia. We searched PubMed with the keywords "negative symptoms," "deficit schizophrenia," "persistent negative symptoms," "neurotransmissions," "neuroimaging" and "genetic." Additional articles were identified by manually checking the reference lists of the relevant publications. Publications in English were considered, and unpublished studies, conference abstracts and poster presentations were not included. Structural and functional imaging studies addressed the issue of neurobiological background of negative symptoms from several perspectives (considering them as a unitary construct, focusing on primary and/or persistent negative symptoms and, more recently, clustering them into factors), but produced discrepant findings. The examined studies provided evidence suggesting that even primary and persistent negative symptoms include different psychopathological constructs, probably reflecting the dysfunction of different neurobiological substrates. Furthermore, they suggest that complex alterations in multiple neurotransmitter systems and genetic variants might influence the expression of negative symptoms in schizophrenia. On the whole, the reviewed findings, representing the distillation of a large body of disparate data, suggest that further deconstruction of negative symptomatology into more elementary components is needed to gain insight into underlying neurobiological mechanisms. PMID:25797499

  15. The 'negative cost' of value engineering.

    PubMed

    Wilkinson, Martin

    2012-06-01

    Martin Wilkinson, national sales manager at system protection specialist, Spirotech UK, highlights the 'potential negative consequences' of value engineering in heating system specification in the healthcare sector, and argues that system protection products such as de-aerators and dirt separators have considerable value in preventative maintenance, and in helping to extend the useful life of both the system as a whole, and its vital parts. PMID:22764628

  16. The Syntax-PF Interface in Children's Negative Sentences

    ERIC Educational Resources Information Center

    Thornton, Rosalind; Rombough, Kelly

    2015-01-01

    To test between two recent accounts of the early stages in the acquisition of negation, we conducted an elicited production study with 25 children, between 2;05 and 3;04 (mean 2;11). The experimental study produced a robust set of negative sentences, with considerable individual variation. Although 13 of the child participants mainly produced…

  17. Experimental Evaluation of a Negative Ion Source for a Heavy Ion Fusion Negative Ion Driver

    SciTech Connect

    Grisham, L. R.; Hahto, S. K.; Hahto, S. T.; Kwan, J. W.; Leung, K. N.

    2004-06-16

    Negative halogen ions have recently been proposed as a possible alternative to positive ions for heavy ion fusion drivers because electron accumulation would not be a problem in the accelerator, and if desired, the beams could be photo-detached to neutrals. To test the ability to make suitable quality beams, an experiment was conducted at Lawrence Berkeley National Laboratory using chlorine in an RF-driven ion source. Without introducing any cesium (which is required to enhance negative ion production in hydrogen ion sources) a negative chlorine current density of 45 mA/cm{sup 2} was obtained under the same conditions that gave 57 45 mA/cm{sup 2} of positive chlorine, suggesting the presence of nearly as many negative ions as positive ions in the plasma near the extraction plane. The negative ion spectrum was 99.5% atomic chlorine ions, with only 0.5% molecular chlorine, and essentially no impurities. Although this experiment did not incorporate the type of electron suppression technology that i s used in negative hydrogen beam extraction, the ratio of co-extracted electrons to Cl{sup -} was as low as 7 to 1, many times lower than the ratio of their mobilities, suggesting that few electrons are present in the near-extractor plasma. This, along with the near-equivalence of the positive and negative ion currents, suggests that the plasma in this region was mostly an ion-ion plasma. The negative chlorine current density was relatively insensitive to pressure, and scaled linearly with RF power. If this linear scaling continues to hold at higher RF powers, it should permit current densities of 100 45 mA/cm{sup 2}, sufficient for present heavy ion fusion injector concepts. The effective ion temperatures of the positive and negative ions appeared to be similar and relatively low for a plasma source.

  18. Experimental evaluation of a negative ion source for a heavy ionfusion negative ion driver

    SciTech Connect

    Grisham, L.R.; Hahto, S.K.; Hahto, S.T.; Kwan, J.W.; Leung, K.N.

    2005-01-18

    Negative halogen ions have recently been proposed as a possible alternative to positive ions for heavy ion fusion drivers because electron accumulation would not be a problem in the accelerator, and if desired, the beams could be photodetached to neutrals [1,2,3]. To test the ability to make suitable quality beams, an experiment was conducted at Lawrence Berkeley National Laboratory using chlorine in an RF-driven ion source. Without introducing any cesium (which is required to enhance negative ion production in hydrogen ion sources) a negative chlorine current density of 45 mA/cm{sup 2} was obtained under the same conditions that gave 57 mA/cm{sup 2} of positive chlorine, suggesting the presence of nearly as many negative ions as positive ions in the plasma near the extraction plane. The negative ion spectrum was 99.5% atomic chlorine ions, with only 0.5% molecular chlorine, and essentially no impurities. Although this experiment did not incorporate the type of electron suppression technology that is used in negative hydrogen beam extraction, the ratio of co-extracted electrons to Cl{sup -} was as low as 7 to 1, many times lower than the ratio of their mobilities, suggesting that few electrons are present in the near-extractor plasma. This, along with the near-equivalence of the positive and negative ion currents, suggests that the plasma in this region was mostly an ion-ion plasma. The negative chlorine current density was relatively insensitive to pressure, and scaled linearly with RF power. If this linear scaling continues to hold at higher RF powers, it should permit current densities of 100 mA/cm{sup 2}, sufficient for present heavy ion fusion injector concepts. The effective ion temperatures of the positive and negative ions appeared to be similar and relatively low for a plasma source.

  19. Negation in the Chaamling Language.

    ERIC Educational Resources Information Center

    Rai, Vishnu S.

    This paper examines the different ways of forming negative sentences in the Chaamling language, an indigenous language spoken in the eastern, hilly districts of Nepal. It explains that negation, or negativization, in the Chaamling language is done with the help of affixation. In imperative sentences, the prefix mi- is added to the verb, which is…

  20. Three chamber negative ion source

    DOEpatents

    Leung, Ka-Ngo; Ehlers, Kenneth W.; Hiskes, John R.

    1985-01-01

    A negative ion vessel is divided into an excitation chamber, a negative ionization chamber and an extraction chamber by two magnetic filters. Input means introduces neutral molecules into a first chamber where a first electron discharge means vibrationally excites the molecules which migrate to a second chamber. In the second chamber a second electron discharge means ionizes the molecules, producing negative ions which are extracted into or by a third chamber. A first magnetic filter prevents high energy electrons from entering the negative ionization chamber from the excitation chamber. A second magnetic filter prevents high energy electrons from entering the extraction chamber from the negative ionizing chamber. An extraction grid at the end of the negative ion vessel attracts negative ions into the third chamber and accelerates them. Another grid, located adjacent to the extraction grid, carries a small positive voltage in order to inhibit positive ions from migrating into the extraction chamber and contour the plasma potential. Additional electrons can be suppressed from the output flux using ExB forces provided by magnetic field means and the extractor grid electric potential.

  1. Isotropic Negative Thermal Expansion Metamaterials.

    PubMed

    Wu, Lingling; Li, Bo; Zhou, Ji

    2016-07-13

    Negative thermal expansion materials are important and desirable in science and engineering applications. However, natural materials with isotropic negative thermal expansion are rare and usually unsatisfied in performance. Here, we propose a novel method to achieve two- and three-dimensional negative thermal expansion metamaterials via antichiral structures. The two-dimensional metamaterial is constructed with unit cells that combine bimaterial strips and antichiral structures, while the three-dimensional metamaterial is fabricated by a multimaterial 3D printing process. Both experimental and simulation results display isotropic negative thermal expansion property of the samples. The effective coefficient of negative thermal expansion of the proposed models is demonstrated to be dependent on the difference between the thermal expansion coefficient of the component materials, as well as on the circular node radius and the ligament length in the antichiral structures. The measured value of the linear negative thermal expansion coefficient of the three-dimensional sample is among the largest achieved in experiments to date. Our findings provide an easy and practical approach to obtaining materials with tunable negative thermal expansion on any scale. PMID:27333052

  2. Toward laser cooling of negative lanthanum

    NASA Astrophysics Data System (ADS)

    Jordan, Elena; Cerchiari, Giovanni; Erlewein, Stefan; Kellerbauer, Alban; UNIC Team

    2016-05-01

    Anion laser cooling holds the potential to allow the production of ultracold ensembles of any negatively charged species by sympathetic cooling. It is a promising technique for cooling of antiprotons to a few mK and could clear the way for precision measurements on cold antihydrogen. Laser cooling of negative ions has never been achieved, since most species have no bound-bound electric dipole transitions. Negative lanthanum (La-) is one of the few anions with multiple electric dipole transitions. The bound-bound transition from the 3F2e ground state to the 3D1o excited state in La- has been proposed theoretically as a candidate for laser cooling. The potential laser cooling transition was identified using laser photodetachment spectroscopy and its excitation energy was measured. We have studied the aforementioned transition in a beam of La anions by high-resolution laser photodetachment spectroscopy. Seven of the nine expected hyperfine structure transitions have been resolved and the transition cross sections have been estimated from experimental observations. It was found that presently La- is the most promising candidate among the atomic anions. We plan to demonstrate the first direct laser cooling of negative ions in a linear radio frequency trap. We gratefully acknowledge support from the European Research Council (ERC).

  3. Lower body negative pressure device

    NASA Technical Reports Server (NTRS)

    Nolte, R. W.

    1977-01-01

    The Lower Body Negative Pressure Device was used, in the space environment, to stress the astronaut's cardiovascular system, to determine the extent and time course of his cardiovascular deconditioning and to determine whether in-flight data from experiment M092, Lower Body Negative Pressure, would be useful in predicting postflight status of orthostatic tolerance. The lower portion of the subject's body was enclosed in this device for the purpose of applying regulated and controlled negative pressure. A description is given of the device.

  4. Negative base encoding in optical linear algebra processors

    NASA Technical Reports Server (NTRS)

    Perlee, C.; Casasent, D.

    1986-01-01

    In the digital multiplication by analog convolution algorithm, the bits of two encoded numbers are convolved to form the product of the two numbers in mixed binary representation; this output can be easily converted to binary. Attention is presently given to negative base encoding, treating base -2 initially, and then showing that the negative base system can be readily extended to any radix. In general, negative base encoding in optical linear algebra processors represents a more efficient technique than either sign magnitude or 2's complement encoding, when the additions of digitally encoded products are performed in parallel.

  5. Negative ion source development for fusion application (invited).

    PubMed

    Takeiri, Yasuhiko

    2010-02-01

    Giant negative ion sources, producing high-current of several tens amps with high energy of several hundreds keV to 1 MeV, are required for a neutral beam injector (NBI) in a fusion device. The giant negative ion sources are cesium-seeded plasma sources, in which the negative ions are produced on the cesium-covered surface. Their characteristic features are discussed with the views of large-volume plasma production, large-area beam acceleration, and high-voltage dc holding. The international thermonuclear experimental reactor NBI employs a 1 MeV-40 A of deuterium negative ion source, and intensive development programs for the rf-driven source plasma production and the multistage electrostatic acceleration are in progress, including the long pulse operation for 3600 s. Present status of the development, as well as the achievements of the giant negative ion sources in the working injectors, is also summarized. PMID:20192420

  6. Negative ion source development for fusion application (invited)

    SciTech Connect

    Takeiri, Yasuhiko

    2010-02-15

    Giant negative ion sources, producing high-current of several tens amps with high energy of several hundreds keV to 1 MeV, are required for a neutral beam injector (NBI) in a fusion device. The giant negative ion sources are cesium-seeded plasma sources, in which the negative ions are produced on the cesium-covered surface. Their characteristic features are discussed with the views of large-volume plasma production, large-area beam acceleration, and high-voltage dc holding. The international thermonuclear experimental reactor NBI employs a 1 MeV-40 A of deuterium negative ion source, and intensive development programs for the rf-driven source plasma production and the multistage electrostatic acceleration are in progress, including the long pulse operation for 3600 s. Present status of the development, as well as the achievements of the giant negative ion sources in the working injectors, is also summarized.

  7. Piezoelectric enhancement under negative pressure

    NASA Astrophysics Data System (ADS)

    Kvasov, Alexander; McGilly, Leo J.; Wang, Jin; Shi, Zhiyong; Sandu, Cosmin S.; Sluka, Tomas; Tagantsev, Alexander K.; Setter, Nava

    2016-07-01

    Enhancement of ferroelectric properties, both spontaneous polarization and Curie temperature under negative pressure had been predicted in the past from first principles and recently confirmed experimentally. In contrast, piezoelectric properties are expected to increase by positive pressure, through polarization rotation. Here we investigate the piezoelectric response of the classical PbTiO3, Pb(Zr,Ti)O3 and BaTiO3 perovskite ferroelectrics under negative pressure from first principles and find significant enhancement. Piezoelectric response is then tested experimentally on free-standing PbTiO3 and Pb(Zr,Ti)O3 nanowires under self-sustained negative pressure, confirming the theoretical prediction. Numerical simulations verify that negative pressure in nanowires is the origin of the enhanced electromechanical properties. The results may be useful in the development of highly performing piezoelectrics, including lead-free ones.

  8. Piezoelectric enhancement under negative pressure.

    PubMed

    Kvasov, Alexander; McGilly, Leo J; Wang, Jin; Shi, Zhiyong; Sandu, Cosmin S; Sluka, Tomas; Tagantsev, Alexander K; Setter, Nava

    2016-01-01

    Enhancement of ferroelectric properties, both spontaneous polarization and Curie temperature under negative pressure had been predicted in the past from first principles and recently confirmed experimentally. In contrast, piezoelectric properties are expected to increase by positive pressure, through polarization rotation. Here we investigate the piezoelectric response of the classical PbTiO3, Pb(Zr,Ti)O3 and BaTiO3 perovskite ferroelectrics under negative pressure from first principles and find significant enhancement. Piezoelectric response is then tested experimentally on free-standing PbTiO3 and Pb(Zr,Ti)O3 nanowires under self-sustained negative pressure, confirming the theoretical prediction. Numerical simulations verify that negative pressure in nanowires is the origin of the enhanced electromechanical properties. The results may be useful in the development of highly performing piezoelectrics, including lead-free ones. PMID:27396411

  9. Factors identified for negative appendicectomies.

    PubMed

    Mirza, M R; Habib, L; Jaleel, F

    2009-07-01

    The study was done, to determine the factors for negative appendicectomies. This prospective descriptive study includes patients managed at four non teaching and a teaching hospital of Karachi from March 2006 to February 2008. One hundred and sixty eight patients underwent appendicectomy during the study period. Details of clinical presentations, investigations, operative findings and histopathology were entered and analyzed. Literature search was aimed to see the negative appendicectomy rate (NAR) in last ten years despite using diagnostic tools (clinical scoring, diagnostic imaging and laparoscopy). In this study a total number of 168 patients under went appendicectomy. Normal appendices were found in 31 patients (negative appendicectomy rate was 18.45%) and associated pathology was seen in 13 patients, an incidental finding of Meckel's diverticulum in 5 patients and no other pathology was seen in 13 patients. The different factors which we identified for negative appendicectomies in our practice were non teaching hospitals where diagnostic scoring system was difficult to apply, female gender, selective use of imaging modality, other pathologies presenting with pain in right lower quadrant (RLQ) and requiring surgical intervention, and non-availability of CT scan and laparoscopy. Despite many advances in diagnostic system, acute appendicitis is still a diagnostic dilemma at times. Although there is no substitute for clinical judgment but in sub groups of patients in whom the possibility of negative appendicectomy is high, diagnostic modalities should be used judiciously to decrease the negative exploration. PMID:19623147

  10. [Negative symptoms and cerebral imaging].

    PubMed

    Kaladjian, A; Belzeaux, R; Adida, M; Azorin, J-M

    2015-12-01

    A number of neuroanatomical and neurofonctional abnormalities have been evidenced by cerebral imaging studies in patients suffering from schizophrenia. Nevertheless, those specifically associated with the negative symptoms of this disease are still insufficiently known. This work is a review of selected studies that have assessed the brain correlates of negative symptoms in schizophrenia. Approaches using structural imaging have highlighted reduction of gray matter density or cortical thickness associated with negative symptoms, which is rather sparsely distributed within the frontal and temporal regions, localized nevertheless more particularly in the frontal medial and orbitofrontal areas, as well as the amygdalo-hippocampic complex. These deficits are concurrent with a loss of integrity of the principal paths of white matter tracts between frontal and limbic regions. On the other hand, neurofonctional abnormalities associated with negative symptoms involve especially the frontal areas and limbic striatum. A disturbed functioning within the fronto-striatal loops, related to a striatal dopaminergic deficit, may represent a potential explanatory hypothesis of the negative symptoms of schizophrenia, as suggested by studies using Positron Emission Tomography on this topic or neuroimaging studies on the effects of antipsychotics. A better identification of the cerebral abnormalities associated with the negative dimension of schizophrenia, with regard to the lateralization of these abnormalities or to their changes during the course of the disease, could offer new therapeutic modalities for the treatment of this dimension which, until now, remains few responsive to conventional pharmacological treatments. PMID:26776387

  11. Cesium injection system for negative ion duoplasmatrons

    DOEpatents

    Kobayashi, Maasaki; Prelec, Krsto; Sluyters, Theodorus J

    1978-01-01

    Longitudinally extending, foraminous cartridge means having a cylindrical side wall forming one flat, circular, tip end surface and an opposite end; an open-ended cavity, and uniformly spaced orifices for venting the cavity through the side wall in the annulus of a plasma ring for uniformly ejecting cesium for coating the flat, circular, surface. To this end, the cavity is filled with a cesium containing substance and attached to a heater in a hollow-discharge duoplasmatron. By coating the flat circular surface with a uniform monolayer of cesium and locating it in an electrical potential well at the end of a hollow-discharge, ion duoplasmatron source of an annular hydrogen plasma ring, the negative hydrogen production from the duoplasmatron is increased. The negative hydrogen is produced on the flat surface of the cartridge and extracted by the electrical potential well along a trajectory coaxial with the axis of the plasma ring.

  12. Negative Transportation and Cross-Linguistic Negative Evidence.

    ERIC Educational Resources Information Center

    Soga, Matsuo

    1972-01-01

    This paper considers whether the negative transportation (NT) rule operating in English is operative also in Japanese and whether investigation of the phenomenon in Japanese may provide new insights for English research. The discussion begins with an explanation and examples of the NT rule in English. Japanese cases are then studied, and the…

  13. Negativity Bias in Dangerous Drivers

    PubMed Central

    Chai, Jing; Qu, Weina; Sun, Xianghong; Zhang, Kan; Ge, Yan

    2016-01-01

    The behavioral and cognitive characteristics of dangerous drivers differ significantly from those of safe drivers. However, differences in emotional information processing have seldom been investigated. Previous studies have revealed that drivers with higher anger/anxiety trait scores are more likely to be involved in crashes and that individuals with higher anger traits exhibit stronger negativity biases when processing emotions compared with control groups. However, researchers have not explored the relationship between emotional information processing and driving behavior. In this study, we examined the emotional information processing differences between dangerous drivers and safe drivers. Thirty-eight non-professional drivers were divided into two groups according to the penalty points that they had accrued for traffic violations: 15 drivers with 6 or more points were included in the dangerous driver group, and 23 drivers with 3 or fewer points were included in the safe driver group. The emotional Stroop task was used to measure negativity biases, and both behavioral and electroencephalograph data were recorded. The behavioral results revealed stronger negativity biases in the dangerous drivers than in the safe drivers. The bias score was correlated with self-reported dangerous driving behavior. Drivers with strong negativity biases reported having been involved in mores crashes compared with the less-biased drivers. The event-related potentials (ERPs) revealed that the dangerous drivers exhibited reduced P3 components when responding to negative stimuli, suggesting decreased inhibitory control of information that is task-irrelevant but emotionally salient. The influence of negativity bias provides one possible explanation of the effects of individual differences on dangerous driving behavior and traffic crashes. PMID:26765225

  14. Sigma models with negative curvature

    NASA Astrophysics Data System (ADS)

    Alonso, Rodrigo; Jenkins, Elizabeth E.; Manohar, Aneesh V.

    2016-05-01

    We construct Higgs Effective Field Theory (HEFT) based on the scalar manifold Hn, which is a hyperbolic space of constant negative curvature. The Lagrangian has a non-compact O (n , 1) global symmetry group, but it gives a unitary theory as long as only a compact subgroup of the global symmetry is gauged. Whether the HEFT manifold has positive or negative curvature can be tested by measuring the S-parameter, and the cross sections for longitudinal gauge boson and Higgs boson scattering, since the curvature (including its sign) determines deviations from Standard Model values.

  15. The Negative Effects of Volatile Sulphur Compounds.

    PubMed

    Milella, Lisa

    2015-01-01

    Oral malodor has been studied extensively in humans but not necessarily to the same degree in our veterinary patients where malodor constitutes a significant problem. Breath malodor may originate from the mouth, or from an extra oral source, originating from other organ systems such as gastrointestinal, respiratory, or even systemic disease. Oral malodor is a result of microbial metabolism of exogenous and endogenous proteinaceous substrates leading to the production of compounds such as indole, skatole, tyramine, cadaverine, puterescine, mercaptans, and sulphides. Volatile sulphur compounds have been shown to be the main cause of oral malodor. Although most clients perceive oral malodor to be primarily a cosmetic problem, there is an increasing volume of evidence in human dental literature demonstrating that volatile sulphur compounds produced by bacteria, even at low concentrations, are toxic to tissues and play a role in the pathogenesis of periodontitis. This article reviews the current available literature in human dentistry looking at these negative effects. No veterinary studies have been conducted looking at the negative effects of volatile sulphur compounds specifically, but as this article highlights, we should be aware of the potential negative effects of volatile sulphur compounds and consider this an area of future research. PMID:26415386

  16. Negative Geography: Locating Things Elsewhere.

    ERIC Educational Resources Information Center

    Stoddard, Robert H.

    The phenomenon of negative geography--the assertion that any location is better than the one selected--is discussed and ways in which this approach differs from traditional geography methodology are analyzed. Case studies of two citizens' groups which protested the relocation of a city mission and halfway house in their neighborhoods illustrate…

  17. Metalinguistic Negation in English and Arabic

    ERIC Educational Resources Information Center

    Nedwick, Kelly M.

    2014-01-01

    Negation is a unique and fascinating property of human language which has been given extensive theoretical and typological treatment. One categorization divides negation use into metalinguistic negation and descriptive negation (Horn, 1985). Descriptive negation (DN) is the truth-functional semantic operator which has received the most attention…

  18. Efficient cesiation in RF driven surface plasma negative ion source

    NASA Astrophysics Data System (ADS)

    Belchenko, Yu.; Ivanov, A.; Konstantinov, S.; Sanin, A.; Sotnikov, O.

    2016-02-01

    Experiments on hydrogen negative ions production in the large radio-frequency negative ion source with cesium seed are described. The system of directed cesium deposition to the plasma grid periphery was used. The small cesium seed (˜0.5 G) provides an enhanced H- production during a 2 month long experimental cycle. The gradual increase of negative ion yield during the long-term source runs was observed after cesium addition to the source. The degraded H- production was recorded after air filling to the source or after the cesium washing away from the driver and plasma chamber walls. The following source conditioning by beam shots produces the gradual recovery of H- yield to the high value. The effect of H- yield recovery after cesium coverage passivation by air fill was studied. The concept of cesium coverage replenishment and of H- yield recovery due to sputtering of cesium from the deteriorated layers is discussed.

  19. Efficient cesiation in RF driven surface plasma negative ion source.

    PubMed

    Belchenko, Yu; Ivanov, A; Konstantinov, S; Sanin, A; Sotnikov, O

    2016-02-01

    Experiments on hydrogen negative ions production in the large radio-frequency negative ion source with cesium seed are described. The system of directed cesium deposition to the plasma grid periphery was used. The small cesium seed (∼0.5 G) provides an enhanced H(-) production during a 2 month long experimental cycle. The gradual increase of negative ion yield during the long-term source runs was observed after cesium addition to the source. The degraded H(-) production was recorded after air filling to the source or after the cesium washing away from the driver and plasma chamber walls. The following source conditioning by beam shots produces the gradual recovery of H(-) yield to the high value. The effect of H(-) yield recovery after cesium coverage passivation by air fill was studied. The concept of cesium coverage replenishment and of H(-) yield recovery due to sputtering of cesium from the deteriorated layers is discussed. PMID:26932015

  20. Cosmology with negative absolute temperatures

    NASA Astrophysics Data System (ADS)

    Vieira, J. P. P.; Byrnes, Christian T.; Lewis, Antony

    2016-08-01

    Negative absolute temperatures (NAT) are an exotic thermodynamical consequence of quantum physics which has been known since the 1950's (having been achieved in the lab on a number of occasions). Recently, the work of Braun et al. [1] has rekindled interest in negative temperatures and hinted at a possibility of using NAT systems in the lab as dark energy analogues. This paper goes one step further, looking into the cosmological consequences of the existence of a NAT component in the Universe. NAT-dominated expanding Universes experience a borderline phantom expansion (w < ‑1) with no Big Rip, and their contracting counterparts are forced to bounce after the energy density becomes sufficiently large. Both scenarios might be used to solve horizon and flatness problems analogously to standard inflation and bouncing cosmologies. We discuss the difficulties in obtaining and ending a NAT-dominated epoch, and possible ways of obtaining density perturbations with an acceptable spectrum.

  1. Gram-Negative Flagella Glycosylation

    PubMed Central

    Merino, Susana; Tomás, Juan M.

    2014-01-01

    Protein glycosylation had been considered as an eccentricity of a few bacteria. However, through advances in analytical methods and genome sequencing, it is now established that bacteria possess both N-linked and O-linked glycosylation pathways. Both glycosylation pathways can modify multiple proteins, flagellins from Archaea and Eubacteria being one of these. Flagella O-glycosylation has been demonstrated in many polar flagellins from Gram-negative bacteria and in only the Gram-positive genera Clostridium and Listeria. Furthermore, O-glycosylation has also been demonstrated in a limited number of lateral flagellins. In this work, we revised the current advances in flagellar glycosylation from Gram-negative bacteria, focusing on the structural diversity of glycans, the O-linked pathway and the biological function of flagella glycosylation. PMID:24557579

  2. Negative effects of positive reinforcement

    PubMed Central

    Perone, Michael

    2003-01-01

    Procedures classified as positive reinforcement are generally regarded as more desirable than those classified as aversive—those that involve negative reinforcement or punishment. This is a crude test of the desirability of a procedure to change or maintain behavior. The problems can be identified on the basis of theory, experimental analysis, and consideration of practical cases. Theoretically, the distinction between positive and negative reinforcement has proven difficult (some would say the distinction is untenable). When the distinction is made purely in operational terms, experiments reveal that positive reinforcement has aversive functions. On a practical level, positive reinforcement can lead to deleterious effects, and it is implicated in a range of personal and societal problems. These issues challenge us to identify other criteria for judging behavioral procedures. ImagesFigure 1Figure 2 PMID:22478391

  3. In defense of negative temperature

    NASA Astrophysics Data System (ADS)

    Poulter, J.

    2016-03-01

    This pedagogical comment highlights three misconceptions concerning the usefulness of the concept of negative temperature, being derived from the usual, often termed Boltzmann, definition of entropy. First, both the Boltzmann and Gibbs entropies must obey the same thermodynamic consistency relation. Second, the Boltzmann entropy does obey the second law of thermodynamics. Third, there exists an integrating factor of the heat differential with both definitions of entropy.

  4. Negative mass solitons in gravity

    NASA Astrophysics Data System (ADS)

    Cebeci, Hakan; Sarıoǧlu, Özgür; Tekin, Bayram

    2006-03-01

    We first reconstruct the conserved (Abbott-Deser) charges in the spin-connection formalism of gravity for asymptotically (Anti)-de Sitter spaces, and then compute the masses of the AdS soliton and the recently found Eguchi-Hanson solitons in generic odd dimensions, unlike the previous result obtained for only five dimensions. These solutions have negative masses compared to the global AdS or AdS/Zp spacetimes. As a separate note, we also compute the masses of the recent even dimensional Taub-NUT-Reissner-Nordström metrics.

  5. Imagery mismatch negativity in musicians.

    PubMed

    Herholz, Sibylle C; Lappe, Claudia; Knief, Arne; Pantev, Christo

    2009-07-01

    The present study investigated musical imagery in musicians and nonmusicians by means of magnetoencephalography (MEG). We used a new paradigm in which subjects had to continue familiar melodies in their mind and then judged if a further presented tone was a correct continuation of the melody. Incorrect tones elicited an imagery mismatch negativity (iMMN) in musicians but not in nonmusicians. This finding suggests that the MMN component can be based on an imagined instead of a sensory memory trace and that imagery of music is modulated by musical expertise. PMID:19673775

  6. Nitric oxide negatively regulates mammalian adult neurogenesis

    NASA Astrophysics Data System (ADS)

    Packer, Michael A.; Stasiv, Yuri; Benraiss, Abdellatif; Chmielnicki, Eva; Grinberg, Alexander; Westphal, Heiner; Goldman, Steven A.; Enikolopov, Grigori

    2003-08-01

    Neural progenitor cells are widespread throughout the adult central nervous system but only give rise to neurons in specific loci. Negative regulators of neurogenesis have therefore been postulated, but none have yet been identified as subserving a significant role in the adult brain. Here we report that nitric oxide (NO) acts as an important negative regulator of cell proliferation in the adult mammalian brain. We used two independent approaches to examine the function of NO in adult neurogenesis. In a pharmacological approach, we suppressed NO production in the rat brain by intraventricular infusion of an NO synthase inhibitor. In a genetic approach, we generated a null mutant neuronal NO synthase knockout mouse line by targeting the exon encoding active center of the enzyme. In both models, the number of new cells generated in neurogenic areas of the adult brain, the olfactory subependyma and the dentate gyrus, was strongly augmented, which indicates that division of neural stem cells in the adult brain is controlled by NO and suggests a strategy for enhancing neurogenesis in the adult central nervous system.

  7. How quantum are non-negative wavefunctions?

    NASA Astrophysics Data System (ADS)

    Hastings, M. B.

    2016-01-01

    We consider wavefunctions which are non-negative in some tensor product basis. We study what possible teleportation can occur in such wavefunctions, giving a complete answer in some cases (when one system is a qubit) and partial answers elsewhere. We use this to show that a one-dimensional wavefunction which is non-negative and has zero correlation length can be written in a "coherent Gibbs state" form, as explained later. We conjecture that such holds in higher dimensions. Additionally, some results are provided on possible teleportation in general wavefunctions, explaining how Schmidt coefficients before measurement limit the possible Schmidt coefficients after measurement, and on the absence of a "generalized area law" [D. Aharonov et al., in Proceedings of Foundations of Computer Science (FOCS) (IEEE, 2014), p. 246; e-print arXiv.org:1410.0951] even for Hamiltonians with no sign problem. One of the motivations for this work is an attempt to prove a conjecture about ground state wavefunctions which have an "intrinsic" sign problem that cannot be removed by any quantum circuit. We show a weaker version of this, showing that the sign problem is intrinsic for commuting Hamiltonians in the same phase as the double semion model under the technical assumption that TQO-2 holds [S. Bravyi et al., J. Math. Phys. 51, 093512 (2010)].

  8. Development of versatile multiaperture negative ion sources

    SciTech Connect

    Cavenago, M.; Minarello, A.; Sattin, M.; Serianni, G.; Antoni, V.; Bigi, M.; Pasqualotto, R.; Recchia, M.; Veltri, P.; Agostinetti, P.; Barbisan, M.; Baseggio, L.; Cervaro, V.; Degli Agostini, F.; Franchin, L.; Laterza, B.; Ravarotto, D.; Rossetto, F.; Zaniol, B.; Zucchetti, S.; and others

    2015-04-08

    Enhancement of negative ion sources for production of large ion beams is a very active research field nowadays, driven from demand of plasma heating in nuclear fusion devices and accelerator applications. As a versatile test bench, the ion source NIO1 (Negative Ion Optimization 1) is being commissioned by Consorzio RFX and INFN. The nominal beam current of 135 mA at −60 kV is divided into 9 beamlets, with multiaperture extraction electrodes. The plasma is sustained by a 2 MHz radiofrequency power supply, with a standard matching box. A High Voltage Deck (HVD) placed inside the lead shielding surrounding NIO1 contains the radiofrequency generator, the gas control, electronics and power supplies for the ion source. An autonomous closed circuit water cooling system was installed for the whole system, with a branch towards the HVD, using carefully optimized helical tubing. Insulation transformer is installed in a nearby box. Tests of several magnetic configurations can be performed. Status of experiments, measured spectra and plasma luminosity are described. Upgrades of magnetic filter, beam calorimeter and extraction grid and related theoretical issues are reviewed.

  9. Negative regulators of cell proliferation

    NASA Technical Reports Server (NTRS)

    Johnson, T. C.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    Cell proliferation is governed by the influence of both mitogens and inhibitors. Although cell contact has long been thought to play a fundamental role in cell cycling regulation, and negative regulators have long been suspected to exist, their isolation and purification has been complicated by a variety of technical difficulties. Nevertheless, over recent years an ever-expanding list of putative negative regulators have emerged. In many cases, their biological inhibitory activities are consistent with density-dependent growth inhibition. Most likely their interactions with mitogenic agents, at an intracellular level, are responsible for either mitotic arrest or continued cell cycling. A review of naturally occurring cell growth inhibitors is presented with an emphasis on those factors shown to be residents of the cell surface membrane. Particular attention is focused on a cell surface sialoglycopeptide, isolated from intact bovine cerebral cortex cells, which has been shown to inhibit the proliferation of an unusually wide range of target cells. The glycopeptide arrest cells obtained from diverse species, both fibroblasts and epithelial cells, and a broad variety of transformed cells. Signal transduction events and a limited spectrum of cells that are refractory to the sialoglycopeptide have provided insight into the molecular events mediated by this cell surface inhibitor.

  10. Dynamically variable negative stiffness structures

    PubMed Central

    Churchill, Christopher B.; Shahan, David W.; Smith, Sloan P.; Keefe, Andrew C.; McKnight, Geoffrey P.

    2016-01-01

    Variable stiffness structures that enable a wide range of efficient load-bearing and dexterous activity are ubiquitous in mammalian musculoskeletal systems but are rare in engineered systems because of their complexity, power, and cost. We present a new negative stiffness–based load-bearing structure with dynamically tunable stiffness. Negative stiffness, traditionally used to achieve novel response from passive structures, is a powerful tool to achieve dynamic stiffness changes when configured with an active component. Using relatively simple hardware and low-power, low-frequency actuation, we show an assembly capable of fast (<10 ms) and useful (>100×) dynamic stiffness control. This approach mitigates limitations of conventional tunable stiffness structures that exhibit either small (<30%) stiffness change, high friction, poor load/torque transmission at low stiffness, or high power active control at the frequencies of interest. We experimentally demonstrate actively tunable vibration isolation and stiffness tuning independent of supported loads, enhancing applications such as humanoid robotic limbs and lightweight adaptive vibration isolators. PMID:26989771

  11. Dynamically variable negative stiffness structures.

    PubMed

    Churchill, Christopher B; Shahan, David W; Smith, Sloan P; Keefe, Andrew C; McKnight, Geoffrey P

    2016-02-01

    Variable stiffness structures that enable a wide range of efficient load-bearing and dexterous activity are ubiquitous in mammalian musculoskeletal systems but are rare in engineered systems because of their complexity, power, and cost. We present a new negative stiffness-based load-bearing structure with dynamically tunable stiffness. Negative stiffness, traditionally used to achieve novel response from passive structures, is a powerful tool to achieve dynamic stiffness changes when configured with an active component. Using relatively simple hardware and low-power, low-frequency actuation, we show an assembly capable of fast (<10 ms) and useful (>100×) dynamic stiffness control. This approach mitigates limitations of conventional tunable stiffness structures that exhibit either small (<30%) stiffness change, high friction, poor load/torque transmission at low stiffness, or high power active control at the frequencies of interest. We experimentally demonstrate actively tunable vibration isolation and stiffness tuning independent of supported loads, enhancing applications such as humanoid robotic limbs and lightweight adaptive vibration isolators. PMID:26989771

  12. Instrumentation for negative ion detection.

    PubMed

    McKeown, M

    1980-06-01

    The instrumentation and practical circuitry required for the detection of negative ions exiting the mass analysis section of a mass spectrometer is examined. The potentials needed to bias the electron multiplier when detecting negative ions from a low ion-energy mass spectrometer, e.g., a quadrupole, are contrasted with the biasing requirements of a mass spectrometer having high ion-energies, e.g., a magnetic sector. Methods of decoupling the biasing high voltage on the signal lead of the multiplier in pulse counting measurements are discussed in detail so that normal, ground referenced input, pulse preamplifiers may be used. Easily understood, practical rules for determining the values of circuit components are given together with a simplified theory of transferring pulse signals from multiplier collector to pulse preamplifier. The changes in circuitry needed when attempting to detect ions by current measurement methods from an electron multiplier area detailed. The effects of leakage currents into athe input of the current preamplifier and their avoidance bay using triaxial shielding on vacuum feed-throughs are explained. The article suggests possible methods of decoupling the high voltage referenced input and the ground referenced output of a current measuring preamplifier. PMID:7428750

  13. Soft 3D acoustic metamaterial with negative index.

    PubMed

    Brunet, Thomas; Merlin, Aurore; Mascaro, Benoit; Zimny, Kevin; Leng, Jacques; Poncelet, Olivier; Aristégui, Christophe; Mondain-Monval, Olivier

    2015-04-01

    Many efforts have been devoted to the design and achievement of negative-refractive-index metamaterials since the 2000s. One of the challenges at present is to extend that field beyond electromagnetism by realizing three-dimensional (3D) media with negative acoustic indices. We report a new class of locally resonant ultrasonic metafluids consisting of a concentrated suspension of macroporous microbeads engineered using soft-matter techniques. The propagation of Gaussian pulses within these random distributions of 'ultra-slow' Mie resonators is investigated through in situ ultrasonic experiments. The real part of the acoustic index is shown to be negative (up to almost - 1) over broad frequency bandwidths, depending on the volume fraction of the microbeads as predicted by multiple-scattering calculations. These soft 3D acoustic metamaterials open the way for key applications such as sub-wavelength imaging and transformation acoustics, which require the production of acoustic devices with negative or zero-valued indices. PMID:25502100

  14. Development of negative ion source at the IPP Nagoya University

    SciTech Connect

    Kuroda, T; Okamura, H; Kaneko, O; Oka, Y

    1980-01-01

    Preliminary experiments have been made to develop a high current H/sup -/ ion surface for a neutral beam injector. Initially, an H/sup -/ ion source of the magnetron type has been investigated in order to determine its physical and technical problems. A second plasma source for negative ion production is under construction, which is based on controlled plasma production. This paper describes preliminary experimental results of the magnetron ion source and some features in the new type of plasma source.

  15. Mismatch Negativity: Translating the Potential

    PubMed Central

    Todd, Juanita; Harms, Lauren; Schall, Ulrich; Michie, Patricia T.

    2013-01-01

    The mismatch negativity (MMN) component of the auditory event-related potential has become a valuable tool in cognitive neuroscience. Its reduced size in persons with schizophrenia is of unknown origin but theories proposed include links to problems in experience-dependent plasticity reliant on N-methyl-d-aspartate glutamate receptors. In this review we address the utility of this tool in revealing the nature and time course of problems in perceptual inference in this illness together with its potential for use in translational research testing animal models of schizophrenia-related phenotypes. Specifically, we review the reasons for interest in MMN in schizophrenia, issues pertaining to the measurement of MMN, its use as a vulnerability index for the development of schizophrenia, the pharmacological sensitivity of MMN and the progress in developing animal models of MMN. Within this process we highlight the challenges posed by knowledge gaps pertaining to the tool and the pharmacology of the underlying system. PMID:24391602

  16. [Negative pressure wound therapy - review].

    PubMed

    Gudmundsdottir, Ingibjorg; Steingrimsson, Steinn; Valsdottir, Elsa; Gudbjartsson, Tomas

    2014-04-01

    Negative pressure wound therapy (NPWT) is a new therapeutic option in wound healing and was first described in its present form in 1997. A vacuum source is used to create sub-atmospheric pressure in the local wound environment to promote healing. This is achieved by connecting a vacuum pump to a tube that is threaded into a wound gauze or foam filler dressing covered with a drape. This concept in wound treatment has been shown to be useful in treating different wound infections, including diabetic wounds as well as complex infections of the abdomen and thorax. NPWT has been used in Iceland for over a decade and its use is steadily increasing. This review describes the indications and outcome of NPWT and is aimed at a broad group of doctors and nurses where recent Icelandic studies on the subject are covered. PMID:24713539

  17. Entanglement negativity in the multiverse

    SciTech Connect

    Kanno, Sugumi; Shock, Jonathan P.; Soda, Jiro

    2015-03-10

    We explore quantum entanglement between two causally disconnected regions in the multiverse. We first consider a free massive scalar field, and compute the entanglement negativity between two causally separated open charts in de Sitter space. The qualitative feature of it turns out to be in agreement with that of the entanglement entropy. We then introduce two observers who determine the entanglement between two causally disconnected de Sitter spaces. When one of the observers remains constrained to a region of the open chart in a de Sitter space, we find that the scale dependence enters into the entanglement. We show that a state which is initially maximally entangled becomes more entangled or less entangled on large scales depending on the mass of the scalar field and recovers the initial entanglement in the small scale limit. We argue that quantum entanglement may provide some evidence for the existence of the multiverse.

  18. Entanglement negativity in the multiverse

    NASA Astrophysics Data System (ADS)

    Kanno, Sugumi; Shock, Jonathan P.; Soda, Jiro

    2015-03-01

    We explore quantum entanglement between two causally disconnected regions in the multiverse. We first consider a free massive scalar field, and compute the entanglement negativity between two causally separated open charts in de Sitter space. The qualitative feature of it turns out to be in agreement with that of the entanglement entropy. We then introduce two observers who determine the entanglement between two causally disconnected de Sitter spaces. When one of the observers remains constrained to a region of the open chart in a de Sitter space, we find that the scale dependence enters into the entanglement. We show that a state which is initially maximally entangled becomes more entangled or less entangled on large scales depending on the mass of the scalar field and recovers the initial entanglement in the small scale limit. We argue that quantum entanglement may provide some evidence for the existence of the multiverse.

  19. Negative Returns to Seniority: New Evidence in Academic Markets.

    ERIC Educational Resources Information Center

    Bratsberg, Bernt; Ragan, James F., Jr.; Warren, John T.

    2003-01-01

    Analysis of a 21-year panel of data on economics professors found only some of the negative relationship between seniority and pay was attributable to low research productivity. Accounting for the quality of the faculty/institution match reduced the inflated estimated returns to seniority. The penalty for 20 years of seniority was 16% of salary.…

  20. Tools to assess negative symptoms in schizophrenia.

    PubMed

    Kane, John M

    2013-06-01

    Although effective treatments for negative symptoms are currently limited, clinicians still need to assess and monitor them because of their impact on patient functioning. Further, documenting patients' negative symptoms provides a complete clinical record that the clinician can use to make systematic and careful treatment decisions. Several tools for assessing negative symptoms in schizophrenia are available, including the Clinical Global Impression scale (CGI), the Brief Psychiatric Rating Scale (BPRS), the Positive and Negative Syndrome Scale (PANSS), the Scale for the Assessment of Negative Symptoms (SANS), the 16-item Negative Symptoms Assessment (NSA-16), and the Schedule for Deficit Syndrome (SDS). Additionally, newer instruments are in development-the Clinical Assessment Interview for Negative Symptoms (CAINS) and the Brief Negative Symptoms Scale (BNSS)-and are yielding promising results. This overview outlines these assessment tools so that clinicians can measure negative symptom severity and track treatment response for their patients with schizophrenia. PMID:23842020

  1. Conceptualization and treatment of negative symptoms in schizophrenia.

    PubMed

    Sarkar, Sonali; Hillner, Kiley; Velligan, Dawn I

    2015-12-22

    Negative symptoms of schizophrenia including social withdrawal, diminished affective response, lack of interest, poor social drive, and decreased sense of purpose or goal directed activity predict poor functional outcomes for patients with schizophrenia. They may develop and be maintained as a result of structural and functional brain abnormalities, particularly associated with dopamine reward pathways and by environmental and psychosocial factors such as self-defeating cognitions and the relief from overstimulation that accompanies withdrawal from social and role functioning. Negative symptoms are more difficult to treat than the positive symptoms of schizophrenia and represent an unmet therapeutic need for large numbers of patients with schizophrenia. While antipsychotic medications to treat the symptoms of schizophrenia have been around for decades, they have done little to address the significant functional impairments in the disorder that are associated with negative symptoms. Negative symptoms and the resulting loss in productivity are responsible for much of the world-wide personal and economic burden of schizophrenia. Pharmacologic treatments may be somewhat successful in treating secondary causes of negative symptoms, such as antipsychotic side effects and depression. However, in the United States there are no currently approved treatments for severe and persistent negative symptoms (PNS) that are not responsive to treatments for secondary causes. Pharmacotherapy and psychosocial treatments are currently being developed and tested with severe and PNS as their primary targets. Academia, clinicians, the pharmaceutical industry, research funders, payers and regulators will need to work together to pursue novel treatments to address this major public health issue. PMID:26740926

  2. Conceptualization and treatment of negative symptoms in schizophrenia

    PubMed Central

    Sarkar, Sonali; Hillner, Kiley; Velligan, Dawn I

    2015-01-01

    Negative symptoms of schizophrenia including social withdrawal, diminished affective response, lack of interest, poor social drive, and decreased sense of purpose or goal directed activity predict poor functional outcomes for patients with schizophrenia. They may develop and be maintained as a result of structural and functional brain abnormalities, particularly associated with dopamine reward pathways and by environmental and psychosocial factors such as self-defeating cognitions and the relief from overstimulation that accompanies withdrawal from social and role functioning. Negative symptoms are more difficult to treat than the positive symptoms of schizophrenia and represent an unmet therapeutic need for large numbers of patients with schizophrenia. While antipsychotic medications to treat the symptoms of schizophrenia have been around for decades, they have done little to address the significant functional impairments in the disorder that are associated with negative symptoms. Negative symptoms and the resulting loss in productivity are responsible for much of the world-wide personal and economic burden of schizophrenia. Pharmacologic treatments may be somewhat successful in treating secondary causes of negative symptoms, such as antipsychotic side effects and depression. However, in the United States there are no currently approved treatments for severe and persistent negative symptoms (PNS) that are not responsive to treatments for secondary causes. Pharmacotherapy and psychosocial treatments are currently being developed and tested with severe and PNS as their primary targets. Academia, clinicians, the pharmaceutical industry, research funders, payers and regulators will need to work together to pursue novel treatments to address this major public health issue. PMID:26740926

  3. 14 CFR 25.943 - Negative acceleration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Negative acceleration. 25.943 Section 25... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.943 Negative acceleration. No... the negative accelerations within the flight envelopes prescribed in § 25.333. This must be shown...

  4. 14 CFR 23.943 - Negative acceleration.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Negative acceleration. 23.943 Section 23... Negative acceleration. No hazardous malfunction of an engine, an auxiliary power unit approved for use in... the airplane is operated at the negative accelerations within the flight envelopes prescribed in §...

  5. 14 CFR 23.943 - Negative acceleration.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Negative acceleration. 23.943 Section 23... Negative acceleration. No hazardous malfunction of an engine, an auxiliary power unit approved for use in... the airplane is operated at the negative accelerations within the flight envelopes prescribed in §...

  6. 14 CFR 23.943 - Negative acceleration.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Negative acceleration. 23.943 Section 23... Negative acceleration. No hazardous malfunction of an engine, an auxiliary power unit approved for use in... the airplane is operated at the negative accelerations within the flight envelopes prescribed in §...

  7. 14 CFR 25.943 - Negative acceleration.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Negative acceleration. 25.943 Section 25... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.943 Negative acceleration. No... the negative accelerations within the flight envelopes prescribed in § 25.333. This must be shown...

  8. 14 CFR 25.943 - Negative acceleration.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Negative acceleration. 25.943 Section 25... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.943 Negative acceleration. No... the negative accelerations within the flight envelopes prescribed in § 25.333. This must be shown...

  9. 14 CFR 25.943 - Negative acceleration.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Negative acceleration. 25.943 Section 25... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.943 Negative acceleration. No... the negative accelerations within the flight envelopes prescribed in § 25.333. This must be shown...

  10. 14 CFR 25.943 - Negative acceleration.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Negative acceleration. 25.943 Section 25... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.943 Negative acceleration. No... the negative accelerations within the flight envelopes prescribed in § 25.333. This must be shown...

  11. 14 CFR 23.943 - Negative acceleration.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Negative acceleration. 23.943 Section 23... Negative acceleration. No hazardous malfunction of an engine, an auxiliary power unit approved for use in... the airplane is operated at the negative accelerations within the flight envelopes prescribed in §...

  12. 14 CFR 23.943 - Negative acceleration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Negative acceleration. 23.943 Section 23... Negative acceleration. No hazardous malfunction of an engine, an auxiliary power unit approved for use in... the airplane is operated at the negative accelerations within the flight envelopes prescribed in §...

  13. Negative dimensional integrals. I. Feynman graphs

    NASA Astrophysics Data System (ADS)

    Halliday, I. G.; Ricotta, R. M.

    1987-07-01

    We propose a new method of evaluating integrals based on negative dimensional integration. We compute Feynman graphs by considering analytic extensions. Propagators are raised to negative integer powers and integrated over negative integer dimensions. We are left with the problem of computing polynomial integrals and summing finite series.

  14. 40 CFR 62.06 - Negative declarations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Negative declarations. 62.06 Section 62....06 Negative declarations. A State may submit to the Administrator a letter certifying that no designated facilities exist in the State if such is the case. The negative declaration will be in lieu of...

  15. Transitions into the negative-energy Dirac continuum

    SciTech Connect

    Krekora, P.; Su, Q.; Grobe, R.

    2004-11-01

    We compare the predictions of the single-particle Dirac equation with quantum field theory for an electron subjected to a space and time dependent field. We demonstrate analytically and numerically that a transition into the negative-energy subspace predicted by the single-particle Dirac equation is directly associated with the degree of suppression of pair-production as described by quantum field theory. We show that the portion of the mathematical wave function that populates the negative-energy states corresponds to the difference between the positron spatial density for systems with and without an electron initially present.

  16. Time evolution of negative ion profile in a large cesiated negative ion source applicable to fusion reactors.

    PubMed

    Yoshida, M; Hanada, M; Kojima, A; Kashiwagi, M; Umeda, N; Hiratsuka, J; Ichikawa, M; Watanabe, K; R Grisham, L; Tsumori, K; Kisaki, M

    2016-02-01

    To understand the physics of the cesium (Cs) recycling in the large Cs-seeded negative ion sources relevant to ITER and JT-60SA with ion extraction area of 45-60 cm × 110-120 cm, the time evolution of the negative ion profile was precisely measured in JT-60SA where the ion extraction area is longitudinally segmented into 5. The Cs was seeded from the oven at 180 °C to the ion source. After 1 g of Cs input, surface production of the negative ions appeared only in the central segment where a Cs nozzle was located. Up to 2 g of Cs, the negative ion profile was longitudinally expanded over full ion extraction area. The measured time evolution of the negative ion profile has the similar tendency of distribution of the Cs atoms that is calculated. From the results, it is suggested that Cs atom distribution is correlated with the formation of the negative ion profile. PMID:26932026

  17. Time evolution of negative ion profile in a large cesiated negative ion source applicable to fusion reactors

    NASA Astrophysics Data System (ADS)

    Yoshida, M.; Hanada, M.; Kojima, A.; Kashiwagi, M.; Umeda, N.; Hiratsuka, J.; Ichikawa, M.; Watanabe, K.; R. Grisham, L.; Tsumori, K.; Kisaki, M.

    2016-02-01

    To understand the physics of the cesium (Cs) recycling in the large Cs-seeded negative ion sources relevant to ITER and JT-60SA with ion extraction area of 45-60 cm × 110-120 cm, the time evolution of the negative ion profile was precisely measured in JT-60SA where the ion extraction area is longitudinally segmented into 5. The Cs was seeded from the oven at 180 °C to the ion source. After 1 g of Cs input, surface production of the negative ions appeared only in the central segment where a Cs nozzle was located. Up to 2 g of Cs, the negative ion profile was longitudinally expanded over full ion extraction area. The measured time evolution of the negative ion profile has the similar tendency of distribution of the Cs atoms that is calculated. From the results, it is suggested that Cs atom distribution is correlated with the formation of the negative ion profile.

  18. [Negative symptoms: clinical and psychometric aspects].

    PubMed

    Adida, M; Azorin, J-M; Belzeaux, R; Fakra, E

    2015-12-01

    Recent investigations performing exploratory and confirmatory factor analysis have suggested that negative symptoms are multidimensional, including evidence for at least two distinct negative symptom subdomains: diminished expression and amotivation. Guidance for selection of instruments for measurement of negative symptoms is rapidly evolving. As there are continuing advances in the description of negative symptoms, new instruments are under development, and new data on the performance of instruments emerge from clinical trials. The Scale for Assessment of Negative Symptoms (SANS), the Positive and Negative Syndrome Scale (PANSS), and the Negative Symptom Assessment-16 (NSA-16) are considered to be reliable and valid measures for negative symptom trials but differ with respect to their domain coverage, use of informants, integration of global scores, administration time and comprehensiveness of their structured interviews. In response to the 2005 NIMH - MATRICS consensus statement, work groups are field testing and refining two new measures, the Clinical Assessment Interview for Negative Symptoms (CAINS) and the Brief Negative Symptom Scale (BNSS). Both address the five currently recognized domains of negative symptoms, differentiate appetitive from consummatory aspects of anhedonia and address desire for social relationships. Thus far, both have exhibited promising psychometric properties. PMID:26776385

  19. Evaluation of negative ion distribution changes by image processing diagnostic

    SciTech Connect

    Ikeda, K. Nakano, H.; Tsumori, K.; Kisaki, M.; Nagaoka, K.; Tokuzawa, T.; Osakabe, M.; Takeiri, Y.; Kaneko, O.; Geng, S.

    2015-04-08

    Distributions of hydrogen Balmer-α (H{sub α}) intensity and its reduction behavior close to a plasma grid (PG) surface have been observed by a spectrally selective imaging system in an arc discharge type negative hydrogen ion source in National Institute for Fusion Science. H{sub α} reduction indicates a reduction of negative hydrogen ions because the mutual neutralization process between H{sup +} and H{sup −} ions causes the dominant excitation process for H{sub α} emission in the rich H{sup −} condition such as in ionic plasma. We observed a significant change in H{sub α} reduction distribution due to change in the bias voltage, which is used to suppress the electron influx. Small H{sub α} reduction in higher bias is likely because the production of negative ions is suppressed by the potential difference between the plasma and PG surface.

  20. Deformation mechanisms in negative Poisson's ratio materials - Structural aspects

    NASA Technical Reports Server (NTRS)

    Lakes, R.

    1991-01-01

    Poisson's ratio in materials is governed by the following aspects of the microstructure: the presence of rotational degrees of freedom, non-affine deformation kinematics, or anisotropic structure. Several structural models are examined. The non-affine kinematics are seen to be essential for the production of negative Poisson's ratios for isotropic materials containing central force linkages of positive stiffness. Non-central forces combined with pre-load can also give rise to a negative Poisson's ratio in isotropic materials. A chiral microstructure with non-central force interaction or non-affine deformation can also exhibit a negative Poisson's ratio. Toughness and damage resistance in these materials may be affected by the Poisson's ratio itself, as well as by generalized continuum aspects associated with the microstructure.

  1. Negative ions in the coma of Comet Halley

    NASA Technical Reports Server (NTRS)

    Chaizy, P.; Reme, H.; Sauvaud, J. A.; D'Uston, C.; Lin, R. P.

    1991-01-01

    The detection of negatively charged cometary ions in the inner coma of Comet Halley is reported. These ions are observed in three broad mass peaks at 7-19, 22-65, and 85-110 AMU, with densities reaching greater than about 1/cu cm, about 0.05/cu cm, and about 0.04/cu cm, respectively, at a distance of about 2300 km from the nucleus. The ion species thought to be present include O(-), OH(-), C(-), CH(-), CN(-) and heavier complex CHO molecular ions. As negative ions are easily destroyed by solar radiation at about 1 AU, an efficient production mechanism, so far unidentified, is required to account for the observed densities. The detection of negative ions in the coma near 1 AU implies that negative ions should also be present in similar neutral gas and dust environment farther away from the sun. If the negative-ion densities are large enough, they could play an important part in physical processes such as radiative transfer or charge exchange.

  2. Nonlinear negative refraction by difference frequency generation

    NASA Astrophysics Data System (ADS)

    Cao, Jianjun; Shen, Dongyi; Feng, Yaming; Wan, Wenjie

    2016-05-01

    Negative refraction has attracted much interest for its promising capability in imaging applications. Such an effect can be implemented by negative index meta-materials, however, which are usually accompanied by high loss and demanding fabrication processes. Recently, alternative nonlinear approaches like phase conjugation and four wave mixing have shown advantages of low-loss and easy-to-implement, but associated problems like narrow accepting angles can still halt their practical applications. Here, we demonstrate theoretically and experimentally a scheme to realize negative refraction by nonlinear difference frequency generation with wide tunability, where a thin Beta barium borate slice serves as a negative refraction layer bending the input signal beam to the idler beam at a negative angle. Furthermore, we realize optical focusing effect using such nonlinear negative refraction, which may enable many potential applications in imaging science.

  3. Electrochemical cell and negative electrode therefor

    DOEpatents

    Kaun, Thomas D.

    1982-01-01

    A secondary electrochemical cell with the positive and negative electrodes separated by a molten salt electrolyte with the negative electrode comprising a particulate mixture of lithium-aluminum alloy and electrolyte and an additive selected from graphitized carbon, Raney iron or mixtures thereof. The lithium-aluminum alloy is present in the range of from about 45 to about 80 percent by volume of the negative electrode, and the electrolyte is present in an amount not less than about 10 percent by volume of the negative electrode. The additive of graphitized carbon is present in the range of from about 1 to about 10 percent by volume of the negative electrode, and the Raney iron additive is present in the range of from about 3 to about 10 percent by volume of the negative electrode.

  4. Effect of fast positive ions incident on caesiated plasma grid of negative ion source

    SciTech Connect

    Bacal, M.

    2012-02-15

    This paper describes the effect on negative ion formation on a caesiated surface of the backscattering of positive ions approaching it with energy of a few tens of eV. For a positive ion energy of 45 eV, the surface produced negative ion current density due to these fast positive ions is 12 times larger than that due to thermal atoms, thus dominating the negative ion surface production instead of the thermal atoms, as considered until now.

  5. Carbon Farming as a Carbon Negative Technology

    NASA Astrophysics Data System (ADS)

    Anderson, C.; Laird, D.; Hayes, D. J.

    2015-12-01

    Carbon farms have a pivotal role in national and international efforts to mitigate and adapt to climate change. A carbon farm in its broadest sense is one that reduces greenhouse gas (GHG) emissions or captures and holds carbon in vegetation and soils. Their capacity to remove carbon from the air and store it safely and permanently, while providing additional human and ecosystem benefits, means they could contribute significantly to national efforts to stabilize or reduce GHGs. We examine carbon farms in the context of corn and soybean production agriculture. We illustrate, using Iowa data but with relevance across United States corn and soybean production, the potential for carbon farms to reduce human GHG emissions and sequester carbon permanently at a rate that has meaningful impact on global greenhouse gas concentration. Carbon has been viewed as a next generation cash crop in Iowa for over a decade. The carbon farm perspective, however, goes beyond carbon as cash crop to make carbon the center of an entire farm enterprise. The transformation is possible through slight adjustment crop practices mixed with advances in technology to sequester carbon through biochar. We examine carbon balance of Iowa agriculture given only the combination of slight reduction in fertilizer and sequestration by biochar. We find the following. Iowa carbon farms could turn Iowa agriculture into a carbon sink. The estimated range of GHG reduction by statewide implementation of carbon farms is 19.46 to 90.27 MMt CO2-equivalent (CO2-e), while the current agricultural CO2-e emission estimate is 35.38 MMt CO2-e. Iowa carbon farm GHG reduction would exceed Iowa GHG reduction by wind energy (8.7 MMt CO2-e) and could exceed combined reductions from wind energy and corn grain ethanol (10.7 MMt CO2-e; 19.4 MMt CO2-e combined). In fact, Iowa carbon farms alone could exceed GHG reduction from national corn grain ethanol production (39.6 MMt CO2-e). A carbon price accessible to agricultural

  6. Absolute negative mobility of interacting Brownian particles

    NASA Astrophysics Data System (ADS)

    Ou, Ya-li; Hu, Cai-tian; Wu, Jian-chun; Ai, Bao-quan

    2015-12-01

    Transport of interacting Brownian particles in a periodic potential is investigated in the presence of an ac force and a dc force. From Brownian dynamic simulations, we find that both the interaction between particles and the thermal fluctuations play key roles in the absolute negative mobility (the particle noisily moves backwards against a small constant bias). When no the interaction acts, there is only one region where the absolute negative mobility occurs. In the presence of the interaction, the absolute negative mobility may appear in multiple regions. The weak interaction can be helpful for the absolute negative mobility, while the strong interaction has a destructive impact on it.

  7. Negative refraction without absorption via quantum coherence

    NASA Astrophysics Data System (ADS)

    Fang, Ai-Ping; Ge, Wenchao; Wang, Meng; Li, Fu-li; Zubairy, M. Suhail

    2016-02-01

    Negative refraction of a probe field is studied in a dense gas consisting of cascade-type four-level atoms. By coupling the magnetic component of the probe field to a Λ scheme with initially prepared coherence in the two lower levels, strong negative permeability with minimal absorption can be obtained. The permittivity of the gas to the electric component of the probe field can be made negative by taking into account the local field effect of the dense atoms. Strong negative refraction with zero absorption can be achieved in a wide range of parameters in our scheme. A possible experimental realization is also discussed.

  8. A Sheath Model for Negative Ion Sources Including the Formation of a Virtual Cathode

    SciTech Connect

    McAdams, R.; King, D. B.; Surrey, E.

    2011-09-26

    A one dimensional model of the sheath between the plasma and the wall in a negative ion source has been developed. The plasma consists of positive ions, electrons and negative ions. The model takes into account the emission of negative ions from the wall into the sheath and thus represents the conditions in a caesiated ion source with surface production of negative ions. At high current densities of the emitted negative ions, the sheath is unable to support the transport of all the negative ions to the plasma and a virtual cathode is formed. This model takes this into account and allows the calculation of the transported negative ions across the sheath with the virtual cathode. The model has been extended to allow the linkage between plasma conditions at the sheath edge and the plasma to be made. Comparisons are made between the results of the model and experimental measurements.

  9. The formation of negatively charged particles in thermoemission plasmas

    SciTech Connect

    Vishnyakov, V. I. Dragan, G. S.; Florko, A. V.

    2008-01-15

    The results of measuring the charges of the magnesium oxide particles formed near a block of metallic magnesium burning in air are presented. It has been found that, apart from positively charged magnesium oxide particles, there are negatively charged particles in the thermoemission plasma of the burning products. It has been shown that within the framework of the model of neutralizing charges, the oxide particles can acquire unlike charges in the thermoemission plasma. The calculations agree with the experimental data.

  10. The formation of negatively charged particles in thermoemission plasmas

    NASA Astrophysics Data System (ADS)

    Vishnyakov, V. I.; Dragan, G. S.; Florko, A. V.

    2008-01-01

    The results of measuring the charges of the magnesium oxide particles formed near a block of metallic magnesium burning in air are presented. It has been found that, apart from positively charged magnesium oxide particles, there are negatively charged particles in the thermoemission plasma of the burning products. It has been shown that within the framework of the model of neutralizing charges, the oxide particles can acquire unlike charges in the thermoemission plasma. The calculations agree with the experimental data.

  11. Development of negative ion extractor in the high-power and long-pulse negative ion source for fusion application.

    PubMed

    Kashiwagi, M; Umeda, N; Tobari, H; Kojima, A; Yoshida, M; Taniguchi, M; Dairaku, M; Maejima, T; Yamanaka, H; Watanabe, K; Inoue, T; Hanada, M

    2014-02-01

    High power and long-pulse negative ion extractor, which is composed of the plasma grid (PG) and the extraction grid (EXG), is newly developed toward the neutral beam injector for heating and current drive of future fusion machines such as ITER, JT-60 Super Advanced and DEMO reactor. The PG is designed to enhance surface production of negative ions efficiently by applying the chamfered aperture. The efficiency of the negative ion production for the discharge power increased by a factor of 1.3 against that of the conventional PG. The EXG is also designed with the thermal analysis to upgrade the cooling capability for the long pulse operation of >1000 s required in ITER. Though the magnetic field for electron suppression is reduced to 0.75 of that in the conventional EXG due to this upgrade, it was experimentally confirmed that the extracted electron current can be suppressed to the allowable level for the long pulse operation. These results show that newly developed extractor has the high potential for the long pulse extraction of the negative ions. PMID:24593597

  12. Development of negative ion extractor in the high-power and long-pulse negative ion source for fusion application

    SciTech Connect

    Kashiwagi, M. Umeda, N.; Tobari, H.; Kojima, A.; Yoshida, M.; Taniguchi, M.; Dairaku, M.; Maejima, T.; Yamanaka, H.; Watanabe, K.; Inoue, T.; Hanada, M.

    2014-02-15

    High power and long-pulse negative ion extractor, which is composed of the plasma grid (PG) and the extraction grid (EXG), is newly developed toward the neutral beam injector for heating and current drive of future fusion machines such as ITER, JT-60 Super Advanced and DEMO reactor. The PG is designed to enhance surface production of negative ions efficiently by applying the chamfered aperture. The efficiency of the negative ion production for the discharge power increased by a factor of 1.3 against that of the conventional PG. The EXG is also designed with the thermal analysis to upgrade the cooling capability for the long pulse operation of >1000 s required in ITER. Though the magnetic field for electron suppression is reduced to 0.75 of that in the conventional EXG due to this upgrade, it was experimentally confirmed that the extracted electron current can be suppressed to the allowable level for the long pulse operation. These results show that newly developed extractor has the high potential for the long pulse extraction of the negative ions.

  13. Walking a Fine Line: Writing Negative Letters in an Insurance Company.

    ERIC Educational Resources Information Center

    Schryer, Catherine F.

    2000-01-01

    Examines the situated-language practices associated with the production of negative letters in an insurance company. Combines textual analyses of a set of negative letters together with writers' accounts of producing these letters to identify effective strategies for composing this correspondence. Identifies some strategies that characterize…

  14. 40 CFR 52.122 - Negative declarations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Negative declarations. 52.122 Section 52.122 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Arizona § 52.122 Negative declarations. (a) The following air pollution control districts...

  15. Negation in the brain: modulating action representations.

    PubMed

    Tettamanti, Marco; Manenti, Rosa; Della Rosa, Pasquale A; Falini, Andrea; Perani, Daniela; Cappa, Stefano F; Moro, Andrea

    2008-11-01

    Sentential negation is a universal syntactic feature of human languages that reverses the truth value expressed by a sentence. An intriguing question concerns what brain mechanisms underlie our ability to represent and understand the meaning of negative sentences. We approach this issue by investigating action-related language processing and the associated neural representations. Using functional magnetic resonance imaging we measured brain activity in 18 healthy subjects during passive listening of sentences characterized by a factorial combination of polarity (affirmative vs. negative) and concreteness (action-related vs. abstract). Negation deactivated cortical areas and the left pallidum. Compared to abstract sentences, action-related sentences activated the left-hemispheric action-representation system. Crucially, the polarity by concreteness interactions showed that the activity within the action-representation system was specifically reduced for negative action-related vs. affirmative action-related sentences (compared to abstract sentences). Accordingly, functional integration within this system as measured by Dynamic Causal Modeling was specifically weaker for negative action-related than for affirmative action-related sentences. This modulation of action representations indicates that sentential negation transiently reduces the access to mental representations of the negated information. PMID:18771737

  16. Criticism and the Ethics of Negative Reviews

    ERIC Educational Resources Information Center

    Peters, Michael A.

    2014-01-01

    This paper is an attempt to work through my own angst at a negative review of my "Education, Philosophy and Politics," reviewed recently by Ian Stronach for the "British Educational Research Journal," and to provide a therapeutic reading of the ethics of negative reviews. What of "shots in the dark" and should there…

  17. Estimation for entanglement negativity of free fermions

    NASA Astrophysics Data System (ADS)

    Herzog, Christopher P.; Wang, Yihong

    2016-07-01

    In this letter we study the negativity of one dimensional free fermions. We derive the general form of the {{{Z}}N} symmetric term in moments of the partial transposed (reduced) density matrix, which is an algebraic function of the end points of the system. Such a path integral turns out to be a convenient tool for making estimations for the negativity.

  18. Negative Knowledge: Understanding Professional Learning and Expertise

    ERIC Educational Resources Information Center

    Gartmeier, Martin; Bauer, Johannes; Gruber, Hans; Heid, Helmut

    2008-01-01

    In this paper, we critically analyze how the concept of negative knowledge contributes to the understanding of professionals' expert practice and learning. Negative knowledge is experientially acquired knowledge about what is wrong and what is to be avoided during performance in a given work situation. In terms of its theoretical foundation, the…

  19. 40 CFR 52.2900 - Negative declaration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Negative declaration. 52.2900 Section... § 52.2900 Negative declaration. (a) Air Pollution Implementation Plan for the Commonwealth of the Northern Mariana Islands. (1) Letter of December 15, 1982, from the Governor to EPA, which is a...

  20. The Negative Binomial Distribution in Quantum Physics

    NASA Astrophysics Data System (ADS)

    Söderholm, Jonas; Inoue, Shuichiro

    2009-06-01

    We give examples of situations where the negative binomial distribution has appeared in quantum physics since its debut in the work of Planck. Several of its properties are reviewed, and Mandel's Q-parameter is shown to play an interesting role. The photon-pair distributions of squeezed vacuum and squeezed single-photon states are identified as negative binomial.

  1. Negative ion spectrometry for detecting nitrated explosives

    NASA Technical Reports Server (NTRS)

    Boettger, H. G.; Yinon, J.

    1975-01-01

    Ionization procedure is modified to produce mainly negative ions by electron capture. Peaks of negative ions are monitored conventionally. Nitrated organic materials could be identified directly from sample sniff inlet stream by suitably modified mass spectrometer because of unique electronegativity which nitro group imparts to organic material.

  2. Negative Priming in Free Recall Reconsidered

    ERIC Educational Resources Information Center

    Hanczakowski, Maciej; Beaman, C. Philip; Jones, Dylan M.

    2016-01-01

    Negative priming in free recall is the finding of impaired memory performance when previously ignored auditory distracters become targets of encoding and retrieval. This negative priming has been attributed to an aftereffect of deploying inhibitory mechanisms that serve to suppress auditory distraction and minimize interference with learning and…

  3. Ionization phenomena and sources of negative ions

    SciTech Connect

    Alton, G.D.

    1983-01-01

    Negative ion source technology has rapidly advanced during the past several years as a direct consequence of the discovery of Krohn that negative ion yields can be greatly enhanced by sputtering in the presence of Group IA elements. Today, most negative ion sources use this discovery directly or the principles implied to effect negative ion formation through surface ionization. As a consequence, the more traditional direct extraction plasma and charge exchange sources are being used less frequently. However, the charge exchange generation mechanism appears to be as universal, is very competitive in terms of efficiency and has the advantage in terms of metastable ion formation. In this review, an attempt has been made to briefly describe the principal processes involved in negative ion formation and sources which are representative of a particular principle. The reader is referred to the literature for specific details concerning the operational characteristics, emittances, brightnesses, species and intensity capabilities of particular sources. 100 references.

  4. Negative incidental emotions augment fairness sensitivity

    PubMed Central

    Liu, Cuizhen; Chai, Jing Wen; Yu, Rongjun

    2016-01-01

    Previous studies have shown that task-unrelated emotions induced incidentally exert carryover effects on individuals’ subsequent decisions in financial negotiations. However, the specificity of these emotion effects are not clear. In three experiments, we systematically investigated the role of seven transiently induced basic emotions (disgust, sadness, anger, fear, happiness, surprise and neutral) on rejection of unfair offers using the ultimatum game. We found that all negative emotions (disgust, sadness, anger and fear), but not happiness or surprise, significantly increased rejection rates, suggesting that the effect of incidental negative emotions on fairness is not specific to the type of negative emotion. Our findings highlight the role of fleeting emotions in biasing decision-making processes and suggest that all incidental negative emotions exert similar effects on fairness sensitivity, possibly by potentiating attention towards negative aspects of the situation. PMID:27101931

  5. Negative incidental emotions augment fairness sensitivity.

    PubMed

    Liu, Cuizhen; Chai, Jing Wen; Yu, Rongjun

    2016-01-01

    Previous studies have shown that task-unrelated emotions induced incidentally exert carryover effects on individuals' subsequent decisions in financial negotiations. However, the specificity of these emotion effects are not clear. In three experiments, we systematically investigated the role of seven transiently induced basic emotions (disgust, sadness, anger, fear, happiness, surprise and neutral) on rejection of unfair offers using the ultimatum game. We found that all negative emotions (disgust, sadness, anger and fear), but not happiness or surprise, significantly increased rejection rates, suggesting that the effect of incidental negative emotions on fairness is not specific to the type of negative emotion. Our findings highlight the role of fleeting emotions in biasing decision-making processes and suggest that all incidental negative emotions exert similar effects on fairness sensitivity, possibly by potentiating attention towards negative aspects of the situation. PMID:27101931

  6. Potential negative ecological effects of corridors.

    PubMed

    Haddad, Nick M; Brudvig, Lars A; Damschen, Ellen I; Evans, Daniel M; Johnson, Brenda L; Levey, Douglas J; Orrock, John L; Resasco, Julian; Sullivan, Lauren L; Tewksbury, Josh J; Wagner, Stephanie A; Weldon, Aimee J

    2014-10-01

    Despite many studies showing that landscape corridors increase dispersal and species richness for disparate taxa, concerns persist that corridors can have unintended negative effects. In particular, some of the same mechanisms that underlie positive effects of corridors on species of conservation interest may also increase the spread and impact of antagonistic species (e.g., predators and pathogens), foster negative effects of edges, increase invasion by exotic species, increase the spread of unwanted disturbances such as fire, or increase population synchrony and thus reduce persistence. We conducted a literature review and meta-analysis to evaluate the prevalence of each of these negative effects. We found no evidence that corridors increase unwanted disturbance or non-native species invasion; however, these have not been well-studied concerns (1 and 6 studies, respectively). Other effects of corridors were more often studied and yielded inconsistent results; mean effect sizes were indistinguishable from zero. The effect of edges on abundances of target species was as likely to be positive as negative. Corridors were as likely to have no effect on antagonists or population synchrony as they were to increase those negative effects. We found 3 deficiencies in the literature. First, despite studies on how corridors affect predators, there are few studies of related consequences for prey population size and persistence. Second, properly designed studies of negative corridor effects are needed in natural corridors at scales larger than those achievable in experimental systems. Third, studies are needed to test more targeted hypotheses about when corridor-mediated effects on invasive species or disturbance may be negative for species of management concern. Overall, we found no overarching support for concerns that construction and maintenance of habitat corridors may result in unintended negative consequences. Negative edge effects may be mitigated by widening

  7. Small membranes under negative surface tension.

    PubMed

    Avital, Yotam Y; Farago, Oded

    2015-03-28

    We use computer simulations and a simple free energy model to study the response of a bilayer membrane to the application of a negative (compressive) mechanical tension. Such a tension destabilizes the long wavelength undulation modes of giant vesicles, but it can be sustained when small membranes and vesicles are considered. Our negative tension simulation results reveal two regimes-(i) a weak negative tension regime characterized by stretching-dominated elasticity and (ii) a strong negative tension regime featuring bending-dominated elastic behavior. This resembles the findings of the classic Evans and Rawicz micropipette aspiration experiment in giant unilamellar vesicles (GUVs) [E. Evans and W. Rawicz, Phys, Rev. Lett. 64, 2094 (1990)]. However, in GUVs the crossover between the two elasticity regimes occurs at a small positive surface tension, while in smaller membranes it takes place at a moderate negative tension. Another interesting observation concerning the response of a small membrane to negative surface tension is related to the relationship between the mechanical and fluctuation tensions, which are equal to each other for non-negative values. When the tension decreases to negative values, the fluctuation tension γ drops somewhat faster than the mechanical tension τ in the small negative tension regime, before it saturates (and becomes larger than τ) for large negative tensions. The bending modulus exhibits an "opposite" trend. It remains almost unchanged in the stretching-dominated elastic regime, and decreases in the bending-dominated regime. Both the amplitudes of the thermal height undulations and the projected area variations diverge at the onset of mechanical instability. PMID:25833604

  8. Small membranes under negative surface tension

    NASA Astrophysics Data System (ADS)

    Avital, Yotam Y.; Farago, Oded

    2015-03-01

    We use computer simulations and a simple free energy model to study the response of a bilayer membrane to the application of a negative (compressive) mechanical tension. Such a tension destabilizes the long wavelength undulation modes of giant vesicles, but it can be sustained when small membranes and vesicles are considered. Our negative tension simulation results reveal two regimes—(i) a weak negative tension regime characterized by stretching-dominated elasticity and (ii) a strong negative tension regime featuring bending-dominated elastic behavior. This resembles the findings of the classic Evans and Rawicz micropipette aspiration experiment in giant unilamellar vesicles (GUVs) [E. Evans and W. Rawicz, Phys, Rev. Lett. 64, 2094 (1990)]. However, in GUVs the crossover between the two elasticity regimes occurs at a small positive surface tension, while in smaller membranes it takes place at a moderate negative tension. Another interesting observation concerning the response of a small membrane to negative surface tension is related to the relationship between the mechanical and fluctuation tensions, which are equal to each other for non-negative values. When the tension decreases to negative values, the fluctuation tension γ drops somewhat faster than the mechanical tension τ in the small negative tension regime, before it saturates (and becomes larger than τ) for large negative tensions. The bending modulus exhibits an "opposite" trend. It remains almost unchanged in the stretching-dominated elastic regime, and decreases in the bending-dominated regime. Both the amplitudes of the thermal height undulations and the projected area variations diverge at the onset of mechanical instability.

  9. How do negative emotions impair self-control? A neural model of negative urgency.

    PubMed

    Chester, David S; Lynam, Donald R; Milich, Richard; Powell, David K; Andersen, Anders H; DeWall, C Nathan

    2016-05-15

    Self-control often fails when people experience negative emotions. Negative urgency represents the dispositional tendency to experience such self-control failure in response to negative affect. Neither the neural underpinnings of negative urgency nor the more general phenomenon of self-control failure in response to negative emotions are fully understood. Previous theorizing suggests that an insufficient, inhibitory response from the prefrontal cortex may be the culprit behind such self-control failure. However, we entertained an alternative hypothesis: negative emotions lead to self-control failure because they excessively tax inhibitory regions of the prefrontal cortex. Using fMRI, we compared the neural activity of people high in negative urgency with controls on an emotional, inhibitory Go/No-Go task. While experiencing negative (but not positive or neutral) emotions, participants high in negative urgency showed greater recruitment of inhibitory brain regions than controls. Suggesting a compensatory function, inhibitory accuracy among participants high in negative urgency was associated with greater prefrontal recruitment. Greater activity in the anterior insula on negatively-valenced, inhibitory trials predicted greater substance abuse one month and one year after the MRI scan among individuals high in negative urgency. These results suggest that, among people whose negative emotions often lead to self-control failure, excessive reactivity of the brain's regulatory resources may be the culprit. PMID:26892861

  10. Negated bio-events: analysis and identification

    PubMed Central

    2013-01-01

    Background Negation occurs frequently in scientific literature, especially in biomedical literature. It has previously been reported that around 13% of sentences found in biomedical research articles contain negation. Historically, the main motivation for identifying negated events has been to ensure their exclusion from lists of extracted interactions. However, recently, there has been a growing interest in negative results, which has resulted in negation detection being identified as a key challenge in biomedical relation extraction. In this article, we focus on the problem of identifying negated bio-events, given gold standard event annotations. Results We have conducted a detailed analysis of three open access bio-event corpora containing negation information (i.e., GENIA Event, BioInfer and BioNLP’09 ST), and have identified the main types of negated bio-events. We have analysed the key aspects of a machine learning solution to the problem of detecting negated events, including selection of negation cues, feature engineering and the choice of learning algorithm. Combining the best solutions for each aspect of the problem, we propose a novel framework for the identification of negated bio-events. We have evaluated our system on each of the three open access corpora mentioned above. The performance of the system significantly surpasses the best results previously reported on the BioNLP’09 ST corpus, and achieves even better results on the GENIA Event and BioInfer corpora, both of which contain more varied and complex events. Conclusions Recently, in the field of biomedical text mining, the development and enhancement of event-based systems has received significant interest. The ability to identify negated events is a key performance element for these systems. We have conducted the first detailed study on the analysis and identification of negated bio-events. Our proposed framework can be integrated with state-of-the-art event extraction systems. The

  11. Process for preparing negative plates for use in a dry charge battery

    SciTech Connect

    Wegner, P.C.

    1986-02-11

    This patent describes a process for the production of lead-containing negative plates for use in a dry charge battery. The process cnsists of drying wet negative plates while protecting them from oxidation. This improvement is accomplished by treating the wet negative plates prior to the drying operation with an aqueous soluton of an oxidation inhibiting agent selected from salicylic acid, and 2-naphtol. The plates are then protected against oxidation during drying; and dry negative plates are obtained which are resistant to the absorption of water from the atmosphere on storage but are wet immediately by battery acid in use.

  12. Negative HPV screening test predicts low cervical cancer risk better than negative Pap test

    Cancer.gov

    Based on a study that included more than 1 million women, investigators at NCI have determined that a negative test for HPV infection compared to a negative Pap test provides greater safety, or assurance, against future risk of cervical cancer.

  13. Quantum inequality restrictions on negative energy densities in curved spacetimes

    NASA Astrophysics Data System (ADS)

    Pfenning, Michael John

    1998-10-01

    In quantum field theory, there exist states in which the expectation value of the energy density for a quantized field is negative. These negative energy densities lead to several problems such as the failure of the classical energy conditions, the production of closed timelike curves and faster than light travel, violations of the second law of thermodynamics, and the possible production of naked singularities. Although quantum field theory introduces negative energies, it also provides constraints in the form of quantum inequalities (QI's). These uncertainty principle- type relations limit the magnitude and duration of any negative energy. We derive a general form of the QI on the energy density for both the quantized scalar and electromagnetic fields in static curved spacetimes. In the case of the scalar field, the QI can be written as the Euclidean wave operator acting on the Euclidean Green's function. Additionally, a small distance expansion on the Green's function is used to derive the QI in the short sampling time limit. It is found that the QI in this limit reduces to the flat space form with subdominant correction terms which depend on the spacetime geometry. Several example spacetimes are studied in which exact forms of the QI's can be found. These include the three- and four-dimensional static Robertson-Walker spacetimes, flat space with perfectly reflecting mirrors, Rindler and static de Sitter space, and the spacetime outside a black hole. In all of the above cases, we find that the quantum inequalities give a lower limit on how much negative energy may be observed relative to the vacuum energy density of the spacetime. For the particular case of the black hole, it is found that the quantum inequality on the energy density is measured relative to the Boulware vacuum. Finally, the application of the quantum inequalities to the Alcubierre warp drive spacetime leads to strict constraints on the thickness of the negative energy region needed to maintain

  14. Information Filtering Based on Users' Negative Opinions

    NASA Astrophysics Data System (ADS)

    Guo, Qiang; Li, Yang; Liu, Jian-Guo

    2013-05-01

    The process of heat conduction (HC) has recently found application in the information filtering [Zhang et al., Phys. Rev. Lett.99, 154301 (2007)], which is of high diversity but low accuracy. The classical HC model predicts users' potential interested objects based on their interesting objects regardless to the negative opinions. In terms of the users' rating scores, we present an improved user-based HC (UHC) information model by taking into account users' positive and negative opinions. Firstly, the objects rated by users are divided into positive and negative categories, then the predicted interesting and dislike object lists are generated by the UHC model. Finally, the recommendation lists are constructed by filtering out the dislike objects from the interesting lists. By implementing the new model based on nine similarity measures, the experimental results for MovieLens and Netflix datasets show that the new model considering negative opinions could greatly enhance the accuracy, measured by the average ranking score, from 0.049 to 0.036 for Netflix and from 0.1025 to 0.0570 for Movielens dataset, reduced by 26.53% and 44.39%, respectively. Since users prefer to give positive ratings rather than negative ones, the negative opinions contain much more information than the positive ones, the negative opinions, therefore, are very important for understanding users' online collective behaviors and improving the performance of HC model.

  15. Communication Analysis focusing Negative Utterances in Combinatorial Thinking Games

    NASA Astrophysics Data System (ADS)

    Nishihara, Yoko; Ohsawa, Yukio

    We have developed a table game named Innovation Game that supports users in thinking up ideas by combining existing products. There are two kinds of players in the Innovation Game, innovators and investors. While the innovators think up ideas and propose them, the investors criticize the ideas and make decisions whether they invest money to the ideas or not. In the Innovation Game, the innovators do not only propose ideas, but also improve the ideas reflecting comments from investors that represent negative impression to the ideas. Although it has been considered that ideas invested much money might be related to negative comments from investors, the relation has not been validated. We analyzed the communications in the Innovation Game. We have found features of communication in which ideas were invested much money. After a proposal of idea by a innovator, investors give negative comments to the innovator. The innovator accepts the negative comments with positive comments and improve their ideas. Finally, the investors satisfy the idea with positive comments and invest much money to them.

  16. Strong Turbulence in Alkali Halide Negative Ion Plasmas

    NASA Astrophysics Data System (ADS)

    Sheehan, Daniel

    1999-11-01

    Negative ion plasmas (NIPs) are charge-neutral plasmas in which the negative charge is dominated by negative ions rather than electrons. They are found in laser discharges, combustion products, semiconductor manufacturing processes, stellar atmospheres, pulsar magnetospheres, and the Earth's ionosphere, both naturally and man-made. They often display signatures of strong turbulence^1. Development of a novel, compact, unmagnetized alkali halide (MX) NIP source will be discussed, it incorporating a ohmically-heated incandescent (2500K) tantulum solenoid (3cm dia, 15 cm long) with heat shields. The solenoid ionizes the MX vapor and confines contaminant electrons, allowing a very dry (electron-free) source. Plasma densities of 10^10 cm-3 and positive to negative ion mass ratios of 1 <= fracm_+m- <= 20 are achievable. The source will allow tests of strong turbulence theory^2. 1 Sheehan, D.P., et al., Phys. Fluids B5, 1593 (1993). 2 Tsytovich, V. and Wharton, C.W., Comm. Plasma Phys. Cont. Fusion 4, 91 (1978).

  17. Cesium Delivery System for Negative Ion Source at IPR

    SciTech Connect

    Bansal, G.; Pandya, K.; Soni, J.; Gahlaut, A.; Parmar, K. G.; Bandyopadhyay, M.; Chakraborty, A.; Singh, M. J.

    2011-09-26

    The technique of surface production of negative ions using cesium, Cs, has been efficiently exploited over the years for producing negative ion beams with increased current densities from negative ion sources used on neutral beam lines. Deposition of Cs on the source walls and the plasma grid lowers the work function and therefore enables a higher yield of H{sup -}, when hydrogen particles (H and/or H{sub x}{sup +}) strike these surfaces.A single driver RF based (100 kW, 1 MHz) negative ion source test bed, ROBIN, is being set up at IPR under a technical collaboration between IPR and IPP, Germany. The optimization of the Cs oven design to be used on this facility as well as multidriver sources is underway. The characterization experiments of such a Cs delivery system with a 1 g Cs inventory have been carried out using surface ionization technique. The experiments have been carried by delivering Cs into a vacuum chamber without plasma. The linear motion of the surface ionization detector, SID, attached with a linear motion feedthrough allows measuring the angular distribution of the Cs coming out of the oven. Based on the experimental results, a Cs oven for ROBIN has been proposed. The Cs oven design and experimental results of the prototype Cs oven are reported and discussed in the paper.

  18. Negative temperatures and the definition of entropy

    NASA Astrophysics Data System (ADS)

    Swendsen, Robert H.; Wang, Jian-Sheng

    2016-07-01

    The concept of negative temperature has recently received renewed interest in the context of debates about the correct definition of the thermodynamic entropy in statistical mechanics. Several researchers have identified the thermodynamic entropy exclusively with the "volume entropy" suggested by Gibbs, and have further concluded that by this definition, negative temperatures violate the principles of thermodynamics. We disagree with these conclusions. We demonstrate that volume entropy is inconsistent with the postulates of thermodynamics for systems with non-monotonic energy densities, while a definition of entropy based on the probability distributions of macroscopic variables does satisfy the postulates of thermodynamics. Our results confirm that negative temperature is a valid extension of thermodynamics.

  19. The false-negative Meckel's scan

    SciTech Connect

    Wilton, G.; Froelich, J.W.

    1982-10-01

    A case is presented of a 17-month-old girl who underwent two Meckel's scans with /sup 99m/Tc pertechnetate. The initial study was interpreted as normal while a subsequent study five days later was definitely positive. Surgery immediately following the positive Meckel's scan demonstrated a Meckel's diverticulum containing gastric mucosa without evidence of active hemorrhage. This prompted a review of the literature in reference to false-negative Meckel's scans which revealed a wide variance in the reported incidence of false-negative examinations. Repeat scintigraphy in the face of a strong clinical suspicion after an initial normal study may decrease the indicence of false-negative imaging series.

  20. Negative Generalization and Symptoms of Anxiety Disorders

    PubMed Central

    Fulford, Daniel; Rosen, Rebecca K.; Johnson, Sheri L.; Carver, Charles S.

    2013-01-01

    The tendency to generalize from a single failure to one's entire self-worth is an important correlate and predictor of depression. Despite conceptual overlap between cognitive biases in anxiety and depression, little research has examined whether negative generalization relates to anxiety symptoms. We examined associations of negative generalization with symptoms of several anxiety disorders, above and beyond its association with lifetime symptoms of depression, among 248 undergraduates. After controlling for lifetime symptoms of major depression, negative generalization was significantly correlated with symptoms of each anxiety disorder tested, most notably generalized anxiety and social phobia. PMID:24340170

  1. Negative Poisson's ratio materials via isotropic interactions.

    PubMed

    Rechtsman, Mikael C; Stillinger, Frank H; Torquato, Salvatore

    2008-08-22

    We show that under tension a classical many-body system with only isotropic pair interactions in a crystalline state can, counterintuitively, have a negative Poisson's ratio, or auxetic behavior. We derive the conditions under which the triangular lattice in two dimensions and lattices with cubic symmetry in three dimensions exhibit a negative Poisson's ratio. In the former case, the simple Lennard-Jones potential can give rise to auxetic behavior. In the latter case, a negative Poisson's ratio can be exhibited even when the material is constrained to be elastically isotropic. PMID:18764632

  2. Negative Poisson's Ratio Materials via Isotropic Interactions

    NASA Astrophysics Data System (ADS)

    Rechtsman, Mikael C.; Stillinger, Frank H.; Torquato, Salvatore

    2008-08-01

    We show that under tension a classical many-body system with only isotropic pair interactions in a crystalline state can, counterintuitively, have a negative Poisson’s ratio, or auxetic behavior. We derive the conditions under which the triangular lattice in two dimensions and lattices with cubic symmetry in three dimensions exhibit a negative Poisson’s ratio. In the former case, the simple Lennard-Jones potential can give rise to auxetic behavior. In the latter case, a negative Poisson’s ratio can be exhibited even when the material is constrained to be elastically isotropic.

  3. Negative and positive cesium ion studies

    NASA Technical Reports Server (NTRS)

    Kuehn, D. G.; Sutliff, D. E.; Chanin, L. M.

    1978-01-01

    Mass spectrometric analyses have been performed on the positive and negative species from discharges in Cs, He-Cs, and He-H2-Cs mixtures. Sampling was conducted through the electrodes of normal glow discharges and from close-spaced heated-cathode conditions, which approximate a cesium thermionic converter. No negative Cs ions were observed for Cs pressures less than .01 torr. Identified species included Cs(+), Cs2(+), Cs(-), and what appeared to be multiply charged ions. Low-mass negative and positive ions attributed to H2 were observed when an He-H2 mixture was also present in the discharge region.

  4. 9 CFR 85.8 - Interstate movement of swine from a qualified negative gene-altered vaccinated herd.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Interstate movement of swine from a... (INCLUDING POULTRY) AND ANIMAL PRODUCTS PSEUDORABIES § 85.8 Interstate movement of swine from a qualified negative gene-altered vaccinated herd. Swine from a qualified negative gene-altered vaccinated herd,...

  5. 9 CFR 85.8 - Interstate movement of swine from a qualified negative gene-altered vaccinated herd.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Interstate movement of swine from a... (INCLUDING POULTRY) AND ANIMAL PRODUCTS PSEUDORABIES § 85.8 Interstate movement of swine from a qualified negative gene-altered vaccinated herd. Swine from a qualified negative gene-altered vaccinated herd,...

  6. 9 CFR 85.8 - Interstate movement of swine from a qualified negative gene-altered vaccinated herd.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Interstate movement of swine from a... (INCLUDING POULTRY) AND ANIMAL PRODUCTS PSEUDORABIES § 85.8 Interstate movement of swine from a qualified negative gene-altered vaccinated herd. Swine from a qualified negative gene-altered vaccinated herd,...

  7. The Negative Testing and Negative Generation Effects Are Eliminated by Delay

    ERIC Educational Resources Information Center

    Mulligan, Neil W.; Peterson, Daniel J.

    2015-01-01

    Although retrieval often enhances subsequent memory (the testing effect), a negative testing effect has recently been documented in which prior retrieval harms later recall compared with restudying. The negative testing effect was predicated on the negative generation effect and the item-specific-relational framework. The present experiments…

  8. PECAM-1 ligation negatively regulates TLR4 signaling in macrophages.

    PubMed

    Rui, Yuxiang; Liu, Xingguang; Li, Nan; Jiang, Yingming; Chen, Guoyou; Cao, Xuetao; Wang, Jianli

    2007-12-01

    Uncontrolled TLR4 signaling may induce excessive production of proinflammatory cytokines and lead to harmful inflammation; therefore, negative regulation of TLR4 signaling attracts much attention now. PECAM-1, a member of Ig-ITIM family, can mediate inhibitory signals in T cells and B cells. However, the role and the mechanisms of PECAM-1 in the regulation of TLR4-mediated LPS response in macrophages remain unclear. In this study, we demonstrate that PECAM-1 ligation with CD38-Fc fusion protein negatively regulates LPS-induced proinflammatory cytokine TNF-alpha, IL-6, and IFN-beta production by inhibiting JNK, NF-kappaB, and IFN regulatory factor 3 activation in macrophages. In addition, PECAM-1 ligation-recruited Src homology region 2 domain-containing phosphatase 1 (SHP-1) and Src homology region 2 domain-containing phosphatase 2 (SHP-2) may be involved in the inhibitory effect of PECAM-1 on TLR4 signaling. Consistently, silencing of PECAM-1 enhances the macrophage response to LPS stimulation. Taken together with the data that PECAM-1 is constitutively expressed in macrophages and its expression is up-regulated by LPS stimulation, PECAM-1 might function as a feedback negative regulator of LPS inflammatory response in macrophages. This study may provide a potential target for intervention of inflammatory diseases. PMID:18025177

  9. Challenges in plasma and extraction modelling of negative ion sources

    NASA Astrophysics Data System (ADS)

    Kalvas, Taneli

    2013-09-01

    The physical processes taking place in negative ion source plasmas are modelled by state-of-the-art 3D particle-in-cell (PIC) codes. These codes are used to gain understanding and to find optimal solutions for negative ion beam production. The PIC codes can be made to match to the reality if all relevant processes were included. This is unfortunately limited by the availability of data about the processes and the huge amount of computational resources needed for the simulations. The optimization of the extraction system and beam transport ion optics is often made using computationally less intensive methods utilized in so-called gun codes. These codes use simplified plasma models to provide a starting point for the extracted beams being simulated. The relatively fast computation allows systematic studies, which are not practical with PIC codes. The gun codes often match well to reality, but they do have difficulties reproducing some effects, especially in negative ion extraction, due to the approximations made in the plasma model. Could the future solutions for beam production modelling couple the two types of simulations?

  10. Microwave gain medium with negative refractive index

    NASA Astrophysics Data System (ADS)

    Ye, Dexin; Chang, Kihun; Ran, Lixin; Xin, Hao

    2014-12-01

    Artificial effective media are attractive because of the fantastic applications they may enable, such as super lensing and electromagnetic invisibility. However, the inevitable loss due to their strongly dispersive nature is one of the fundamental challenges preventing such applications from becoming a reality. In this study, we demonstrate an effective gain medium based on negative resistance, to overcompensate the loss of a conventional passive metamaterial, meanwhile keeping its original negative-index property. Energy conservation-based theory, full-wave simulation and experimental measurement show that a fabricated sample consisting of conventional sub-wavelength building blocks with embedded microwave tunnel diodes exhibits a band-limited Lorentzian dispersion simultaneously with a negative refractive index and a net gain. Our work provides experimental evidence to the assertion that a stable net gain in negative-index gain medium is achievable, proposing a potential solution for the critical challenge current metamateiral technology faces in practical applications.

  11. Negative feedback system reduces pump oscillations

    NASA Technical Reports Server (NTRS)

    Rosenmann, W.

    1967-01-01

    External negative feedback system counteracts low frequency oscillations in rocket engine propellant pumps. The system uses a control piston to sense pump discharge fluid on one side and a gas pocket on the other.

  12. Negative priming in free recall reconsidered.

    PubMed

    Hanczakowski, Maciej; Beaman, C Philip; Jones, Dylan M

    2016-05-01

    Negative priming in free recall is the finding of impaired memory performance when previously ignored auditory distracters become targets of encoding and retrieval. This negative priming has been attributed to an aftereffect of deploying inhibitory mechanisms that serve to suppress auditory distraction and minimize interference with learning and retrieval of task-relevant information. In 6 experiments, we tested the inhibitory account of the effect of negative priming in free recall against alternative accounts. We found that ignoring auditory distracters is neither sufficient nor necessary to produce the effect of negative priming in free recall. Instead, the effect is more readily accounted for by a buildup of proactive interference occurring whenever 2 successively presented lists of words are drawn from the same semantic category. (PsycINFO Database Record PMID:26595066

  13. Cannabis use, schizotypy, and negative priming.

    PubMed

    Albertella, Lucy; Le Pelley, Mike E; Copeland, Jan

    2015-08-30

    The present study examined the effects of frequency of cannabis use, schizotypy, and age on cognitive control, as measured using a location-based negative priming task in a sample of 124 Australians aged 15-24 who had ever used cannabis. This study found that the schizotypy dimension of Impulsive Nonconformity had a significant effect on negative priming such that participants with higher scores on this dimension showed reduced negative priming. Also, higher levels of psychological distress were associated with greater negative priming. Finally, there was a significant age by cannabis use interaction indicating that younger, frequent users of cannabis may be more susceptible to its effects on cognitive control and perhaps at greater risk of developing a disorder on the psychosis dimension. PMID:26154815

  14. Metal [100] Nanowires with Negative Poisson's Ratio.

    PubMed

    Ho, Duc Tam; Kwon, Soon-Yong; Kim, Sung Youb

    2016-01-01

    When materials are under stretching, occurrence of lateral contraction of materials is commonly observed. This is because Poisson's ratio, the quantity describes the relationship between a lateral strain and applied strain, is positive for nearly all materials. There are some reported structures and materials having negative Poisson's ratio. However, most of them are at macroscale, and reentrant structures and rigid rotating units are the main mechanisms for their negative Poisson's ratio behavior. Here, with numerical and theoretical evidence, we show that metal [100] nanowires with asymmetric cross-sections such as rectangle or ellipse can exhibit negative Poisson's ratio behavior. Furthermore, the negative Poisson's ratio behavior can be further improved by introducing a hole inside the asymmetric nanowires. We show that the surface effect inducing the asymmetric stresses inside the nanowires is a main origin of the superior property. PMID:27282358

  15. Superconductive microstrip exhibiting negative differential resistivity

    DOEpatents

    Huebener, R.P.; Gallus, D.E.

    1975-10-28

    A device capable of exhibiting negative differential electrical resistivity over a range of values of current and voltage is formed by vapor- depositing a thin layer of a material capable of exhibiting superconductivity on an insulating substrate, establishing electrical connections at opposite ends of the deposited strip, and cooling the alloy into its superconducting range. The device will exhibit negative differential resistivity when biased in the current- induced resistive state.

  16. [Depressive symptoms and negative symptoms during schizophrenia].

    PubMed

    Dollfus, S; Langlois, S; Assouly-Besse, F; Petit, M

    1995-06-01

    Taking into account the wellknown frequency of depressive and extrapyramidal symptoms in schizophrenia and the rare studies about their evolution, several questions can be raised: How do these different symptoms move? Are there specific characters of each of them? First, stability of negative symptoms evaluated by the Scale for the Assessment of Negative Symptoms (SANS) was studied among 57 schizophrenic patients at admission and at discharge. The course of negative symptoms was compared to that of depressive MADRS (Montgomery et Asberg Depression Rating Scale) and akinetic symptoms (Extrapyramidal Symptom Rating Scale). All the subscores of the SANS decreased significantly but 4 items belonging to the affective flattening subscale and one item belonging to the alogia subscale did not vary significantly, showing the necessity of taking into account the individual items of the SANS rather than the subscale scores to evaluate the course of negative symptoms. Changes in all the SANS subscores except the alogia and anhedonia subscores were associated with variations in scores of other scales. Correlations between the changes of negative symptoms and the changes of depressive symptoms showed the necessity to do more specific scales, for example, scales for depression in schizophrenia. Langlois-Théry et al. (1994) evaluated among 53 schizophrenic patients stabilized with neuroleptic treatment, depressive symptomatology with Echelle de Ralentissement Dépressif (ERD, Widlöcher, 1983) and MADRS, negative symptomatology (Positive and Negative Syndrome Scale) and akinesia (ESRS), to determinate whether ERD composed of 3 subscores (motor, ideic and subjective) could be able to evaluate the depressive symptomatology, independently of the measures of negative and akinetic symptomatology.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7628337

  17. Entropy analysis of systems exhibiting negative probabilities

    NASA Astrophysics Data System (ADS)

    Tenreiro Machado, J. A.

    2016-07-01

    This paper addresses the concept of negative probability and its impact upon entropy. An analogy between the probability generating functions, in the scope of quasiprobability distributions, and the Grünwald-Letnikov definition of fractional derivatives, is explored. Two distinct cases producing negative probabilities are formulated and their distinct meaning clarified. Numerical calculations using the Shannon entropy characterize further the characteristics of the two limit cases.

  18. Negative mass bubbles in de Sitter spacetime

    NASA Astrophysics Data System (ADS)

    Mbarek, Saoussen; Paranjape, M. B.

    2014-11-01

    We study the possibility of the existence of negative mass bubbles within a de Sitter spacetime background with matter content corresponding to a perfect fluid. It is shown that there exist configurations of the perfect fluid that satisfy everywhere the dominant energy condition, the Einstein equations and the equations of hydrostatic equilibrium which asymptotically approach the exact solution of Schwarzschild—de Sitter spacetime with a negative mass.

  19. The negative relief of large river floodplains

    NASA Astrophysics Data System (ADS)

    Lewin, John; Ashworth, Philip J.

    2014-02-01

    Large floodplains have multiple and complex negative relief assemblages in which depressions fall below local or general floodplain surfaces at a variety of scales. The generation and dynamics of negative relief along major alluvial corridors are described and compared. Such depressions are significant for the storage and passage of surface waters, the creation of a range of riparian, wetland, lacustrine and flowing-water habitats, and the long-term accumulation of organic materials.

  20. Waves in geomaterials exhibiting negative stiffness behaviour

    NASA Astrophysics Data System (ADS)

    Esin, Maxim; Dyskin, Arcady; Pasternak, Elena

    2016-04-01

    Negative stiffness denotes the type of material behaviour when the force applied to the body decreases the body's deformation increases. Some geomaterials, for instance, rocks, demonstrate behaviour of this type at certain loads: during the compression tests the loading curves exhibit descending branch (post-peak softening). One of the possible mechanisms of the negative stiffness appearance in geomaterials is rotation of non-spherical grains. It is important to emphasize that in this case the descending branch may be reversible given that the testing machine is stiff enough (in general case it means an importance of boundary conditions). Existence of geomaterials with a negative modulus associated with rotations may have significant importance. In particular, important is understanding of the wave propagation in such materials. We study the stability of geomaterials with negative stiffness inclusions and wave propagation in it using two approaches: Cosserat continuum and discrete mass-spring models. In both cases we consider the rotational degrees of freedom in addition to the conventional translational ones. We show that despite non positiveness of the energy the materials with negative stiffness elements can be stable if certain conditions are met. In the case of Cosserat continuum the Cosserat shear modulus (the modulus relating the non-symmetrical part of shear stress and internal rotations) is allowed to assume negative values as long as its value does not exceed the value of the standard (positive) shear modulus. In the case of discrete mass-spring systems (with translational and rotational springs) the concentration of negative stiffness springs and the absolute values of negative spring stiffness are limited. The critical concentration when the system loses stability and the amplitude of the oscillations tends to infinity is equal to 1/2 and 3/5 for two- and three-dimensional cases respectively.

  1. Classical gravity does not refract negatively.

    PubMed

    McCall, Martin W

    2007-03-01

    We appraise recent claims that classical gravitation can induce negative refraction of electromagnetic radiation in vacuum. By recasting the previous literature in covariant notation, we show that the criterion used hitherto for determining negative refraction in vacuum is inappropriate, and can even be satisfied by parametrized transformations in Minkowski spacetime. Using instead a covariantly acceptable definition, we find that in classical vacuum the power flux of a plane electromagnetic wave points in the direction of phase advance. PMID:17359145

  2. Negative Capacitance transients in a ferroelectric capacitor

    NASA Astrophysics Data System (ADS)

    Khan, Asif; Chatterjee, Korok; Wang, Brian; Drapcho, Steven; You, Long; Serrao, Claudy; Bakaul, Saidur; Ramesh, Ramamoorthy; Salahuddin, Sayeef

    2015-03-01

    The Boltzmann distribution of electrons poses a fundamental barrier to lowering energy dissipation in conventional electronics, often termed as Boltzmann Tyranny. Negative capacitance in ferroelectric materials, which stems from the stored energy of phase transition, could provide a solution, but a direct measurement of negative capacitance has so far been elusive. Here we demonstrate the negative differential capacitance in a thin, single crystalline ferroelectric film, by constructing a simple R-C network and monitoring the voltage dynamics across the ferroelectric capacitor6. When a voltage pulse is applied, the voltage across the ferroelectric capacitor is found to be decreasing with time-in exactly the opposite direction to which voltage for a regular capacitor should change. The results are analyzed on the basis of the Landau-Khalatnikov equation, which shows that as the ferroelectric polarization switches its direction, it passes through the unstable negative capacitance region resulting in the characteristic ``negative capacitance transients.'' Analysis of this ``inductance''-like behavior from a capacitor allows us to calculate the value of the negative capacitance directly and presents an unprecedented insight into the intrinsic energy profile of the ferroelectric material.

  3. Negative capacitance in multidomain ferroelectric superlattices.

    PubMed

    Zubko, Pavlo; Wojdeł, Jacek C; Hadjimichael, Marios; Fernandez-Pena, Stéphanie; Sené, Anaïs; Luk'yanchuk, Igor; Triscone, Jean-Marc; Íñiguez, Jorge

    2016-06-23

    The stability of spontaneous electrical polarization in ferroelectrics is fundamental to many of their current applications, which range from the simple electric cigarette lighter to non-volatile random access memories. Research on nanoscale ferroelectrics reveals that their behaviour is profoundly different from that in bulk ferroelectrics, which could lead to new phenomena with potential for future devices. As ferroelectrics become thinner, maintaining a stable polarization becomes increasingly challenging. On the other hand, intentionally destabilizing this polarization can cause the effective electric permittivity of a ferroelectric to become negative, enabling it to behave as a negative capacitance when integrated in a heterostructure. Negative capacitance has been proposed as a way of overcoming fundamental limitations on the power consumption of field-effect transistors. However, experimental demonstrations of this phenomenon remain contentious. The prevalent interpretations based on homogeneous polarization models are difficult to reconcile with the expected strong tendency for domain formation, but the effect of domains on negative capacitance has received little attention. Here we report negative capacitance in a model system of multidomain ferroelectric-dielectric superlattices across a wide range of temperatures, in both the ferroelectric and paraelectric phases. Using a phenomenological model, we show that domain-wall motion not only gives rise to negative permittivity, but can also enhance, rather than limit, its temperature range. Our first-principles-based atomistic simulations provide detailed microscopic insight into the origin of this phenomenon, identifying the dominant contribution of near-interface layers and paving the way for its future exploitation. PMID:27296225

  4. Groups of Negations on the Unit Square

    PubMed Central

    2014-01-01

    The main results are about the groups of the negations on the unit square, which is considered as a bilattice. It is proven that all the automorphisms on it form a group; the set, containing the monotonic isomorphisms and the strict negations of the first (or the second or the third) kind, with the operator “composition,” is a group G2 (or G3 or G4, correspondingly). All these four kinds of mappings form a group G5. And all the groups Gi, i = 2,3, 4 are normal subgroups of G5. Moreover, for G5, a generator set is given, which consists of all the involutive negations of the second kind and the standard negation of the first kind. As a subset of the unit square, the interval-valued set is also studied. Two groups are found: one group consists of all the isomorphisms on LI, and the other group contains all the isomorphisms and all the strict negations on LI, which keep the diagonal. Moreover, the former is a normal subgroup of the latter. And all the involutive negations on the interval-valued set form a generator set of the latter group. PMID:25197719

  5. [Pneumocystis pneumonia in HIV-negative adults].

    PubMed

    Rouyer, M; Stoclin, A; Blanc, F-X

    2015-12-01

    In HIV-negative adults, Pneumocystis jirovecii pneumonia can be observed when immunodeficiency is present, especially in case of drug-induced immune suppression (steroids, chemotherapy, transplantation). Clinical, radiological, and biological presentations are different in HIV-positive and HIV-negative individuals with different immunodeficiency profiles. In HIV-negative patients, dyspnea occurs more quickly (median duration of 5 days to get a diagnosis), diagnosis is more difficult because of less Pneumocystis in bronchoalveolar lavage, and mortality is higher than in HIV-positive individuals. Lung CT-scan typically shows diffuse ground glass opacities, but peri-bronchovascular condensations or ground glass opacities clearly limited by interlobular septa can also be observed. Lymphopenia is common but CD4+ T-cells count is rarely performed. HIV-negative patients with Pneumocystis pneumonia are co-infected with bacteria, viruses or fungi in about 30% cases. Bronchoalveolar lavage is often more neutrophilic than in HIV-positive individuals. PCR and β-D-glucan have good sensitivity but poor specificity to diagnose Pneumocystis pneumonia. Trimethoprim-sulfamethoxazole remains the first choice of treatment. Duration is 14 days in HIV-negative patients whereas it is typically of 21 days in HIV-positive individuals. Adjunctive corticosteroids are of beneficial effect in HIV-positive adult patients with substantial hypoxaemia but are not recommended in HIV-negative patients, as they could be deleterious in some individuals. PMID:26572261

  6. Negative capacitance in multidomain ferroelectric superlattices

    NASA Astrophysics Data System (ADS)

    Zubko, Pavlo; Wojdeł, Jacek C.; Hadjimichael, Marios; Fernandez-Pena, Stéphanie; Sené, Anaïs; Luk’Yanchuk, Igor; Triscone, Jean-Marc; Íñiguez, Jorge

    2016-06-01

    The stability of spontaneous electrical polarization in ferroelectrics is fundamental to many of their current applications, which range from the simple electric cigarette lighter to non-volatile random access memories. Research on nanoscale ferroelectrics reveals that their behaviour is profoundly different from that in bulk ferroelectrics, which could lead to new phenomena with potential for future devices. As ferroelectrics become thinner, maintaining a stable polarization becomes increasingly challenging. On the other hand, intentionally destabilizing this polarization can cause the effective electric permittivity of a ferroelectric to become negative, enabling it to behave as a negative capacitance when integrated in a heterostructure. Negative capacitance has been proposed as a way of overcoming fundamental limitations on the power consumption of field-effect transistors. However, experimental demonstrations of this phenomenon remain contentious. The prevalent interpretations based on homogeneous polarization models are difficult to reconcile with the expected strong tendency for domain formation, but the effect of domains on negative capacitance has received little attention. Here we report negative capacitance in a model system of multidomain ferroelectric–dielectric superlattices across a wide range of temperatures, in both the ferroelectric and paraelectric phases. Using a phenomenological model, we show that domain-wall motion not only gives rise to negative permittivity, but can also enhance, rather than limit, its temperature range. Our first-principles-based atomistic simulations provide detailed microscopic insight into the origin of this phenomenon, identifying the dominant contribution of near-interface layers and paving the way for its future exploitation.

  7. Detecting Negative Obstacles by Use of Radar

    NASA Technical Reports Server (NTRS)

    Mittskus, Anthony; Lux, James

    2006-01-01

    Robotic land vehicles would be equipped with small radar systems to detect negative obstacles, according to a proposal. The term "negative obstacles" denotes holes, ditches, and any other terrain features characterized by abrupt steep downslopes that could be hazardous for vehicles. Video cameras and other optically based obstacle-avoidance sensors now installed on some robotic vehicles cannot detect obstacles under adverse lighting conditions. Even under favorable lighting conditions, they cannot detect negative obstacles. A radar system according to the proposal would be of the frequency-modulation/ continuous-wave (FM/CW) type. It would be installed on a vehicle, facing forward, possibly with a downward slant of the main lobe(s) of the radar beam(s) (see figure). It would utilize one or more wavelength(s) of the order of centimeters. Because such wavelengths are comparable to the characteristic dimensions of terrain features associated with negative hazards, a significant amount of diffraction would occur at such features. In effect, the diffraction would afford a limited ability to see corners and to see around corners. Hence, the system might utilize diffraction to detect corners associated with negative obstacles. At the time of reporting the information for this article, preliminary analyses of diffraction at simple negative obstacles had been performed, but an explicit description of how the system would utilize diffraction was not available.

  8. A simple Quantum heat engine operating between two negative temperatures

    NASA Astrophysics Data System (ADS)

    Dima, Tolasa A.; Bekele, Mulugeta

    We study a heat engine that operates between two reservoirs at negative temperatures. A system of spin-half particles, in the thermodynamic limit, subject to a time dependent external magnetic field, is used as a working substance because of its capability to demonstrate negative absolute temperature. We explored the finite-time quantities: period, power and efficiency. The engine is explored in its maximum power and optimum mode of operation from which its figure of merit is defined as the product of scaled power and scaled efficiency. We found that power-wise the engine provides better performance under its maximum power mode of operation than the optimized mode; however, efficiency-wise, the optimized mode of operation is better than its maximum mode operation. We thank the Internationa Science programme,IPS, Upsala,Sweden for the support to this research?.

  9. Bacteriocins from Gram-Negative Bacteria: A Classification?

    NASA Astrophysics Data System (ADS)

    Rebuffat, Sylvie

    Bacteria produce an arsenal of toxic peptides and proteins, which are termed bacteriocins and play a role in mediating the dynamics of microbial populations and communities. Bacteriocins from Gram-negative bacteria arise mainly from Enterobacteriaceae. They assemble into two main families: high molecular mass modular proteins (30-80 kDa) termed colicins and low molecular mass peptides (between 1 and 10 kDa) termed microcins. The production of colicins is mediated by the SOS response regulon, which plays a role in the response of many bacteria to DNA damages. Microcins are highly stable hydrophobic peptides that are produced under stress conditions, particularly nutrient depletion. Colicins and microcins are found essentially in Escherichia coli, but several other Gram-negative species also produce bacteriocin-like substances. This chapter presents the basis of a classification of colicins and microcins.

  10. Negative Evaluations of Negative Alcohol Consequences Lead to Subsequent Reductions in Alcohol Use

    PubMed Central

    Barnett, Nancy P.; Merrill, Jennifer E.; Kahler, Christopher W.; Colby, Suzanne M.

    2015-01-01

    Alcohol use during young adulthood may reflect a learning process whereby positive and negative alcohol-related experiences and interpretations of those experiences drive subsequent behavior. Understanding the effect of consequences and the evaluation of consequences could be informative for intervention approaches. Objective To examine the extent to which the number of positive and negative alcohol consequences experienced and the evaluation of those consequences predict subsequent alcohol use and consequences in college students. Method Students at three colleges (N = 679) completed biweekly web-based surveys on alcohol use, positive and negative consequences, and consequence evaluations for two academic years. Hierarchical linear modeling tested whether consequences and evaluations in a given week predicted changes in alcohol use and consequences at the next assessment. Moderation by gender and class year also were evaluated. Results Evaluating past-week negative consequences more negatively than one’s average resulted in decreases in alcohol use at the next assessment. More negative evaluation of negative consequences was followed in the subsequent observation by a higher number of positive consequences for females but not males. A higher number of positive consequences in a given week was followed by a higher number of both positive and negative consequences in the subsequent observation. Number of negative consequences experienced and evaluation of positive consequences had no effect on later behavior. Conclusions Salient negative consequences may drive naturalistic reductions in alcohol use, suggesting the possible efficacy of programs designed to increase the salience of the negative effects of alcohol. PMID:26168225

  11. Negative evaluations of negative alcohol consequences lead to subsequent reductions in alcohol use.

    PubMed

    Barnett, Nancy P; Merrill, Jennifer E; Kahler, Christopher W; Colby, Suzanne M

    2015-12-01

    Alcohol use during young adulthood may reflect a learning process whereby positive and negative alcohol-related experiences and interpretations of those experiences drive subsequent behavior. Understanding the effect of consequences and the evaluation of consequences could be informative for intervention approaches. The objective of this study was to examine the extent to which the number of positive and negative alcohol consequences experienced and the evaluation of those consequences predict subsequent alcohol use and consequences in college students. Students at 3 colleges (N = 679) completed biweekly web-based surveys on alcohol use, positive and negative consequences, and consequence evaluations for 2 academic years. Hierarchical linear modeling tested whether consequences and evaluations in a given week predicted changes in alcohol use and consequences at the next assessment. Moderation by gender and class year were also evaluated. Evaluating past-week negative consequences more negatively than one's average resulted in decreases in alcohol use at the next assessment. More negative evaluation of negative consequences was followed in the subsequent observation by a higher number of positive consequences for females but not for males. A higher number of positive consequences in a given week was followed by a higher number of both positive and negative consequences in the subsequent observation. Number of negative consequences experienced and evaluation of positive consequences had no effect on later behavior. Salient negative consequences may drive naturalistic reductions in alcohol use, suggesting the possible efficacy of programs designed to increase the salience of the negative effects of alcohol. PMID:26168225

  12. Sensitivity of negative subsequent memory and task-negative effects to age and associative memory performance.

    PubMed

    de Chastelaine, Marianne; Mattson, Julia T; Wang, Tracy H; Donley, Brian E; Rugg, Michael D

    2015-07-01

    The present fMRI experiment employed associative recognition to investigate the relationships between age and encoding-related negative subsequent memory effects and task-negative effects. Young, middle-aged and older adults (total n=136) were scanned while they made relational judgments on visually presented word pairs. In a later memory test, the participants made associative recognition judgments on studied, rearranged (items studied on different trials) and new pairs. Several regions, mostly localized to the default mode network, demonstrated negative subsequent memory effects in an across age-group analysis. All but one of these regions also demonstrated task-negative effects, although there was no correlation between the size of the respective effects. Whereas negative subsequent memory effects demonstrated a graded attenuation with age, task-negative effects declined markedly between the young and the middle-aged group, but showed no further reduction in the older group. Negative subsequent memory effects did not correlate with memory performance within any age group. By contrast, in the older group only, task-negative effects predicted later memory performance. The findings demonstrate that negative subsequent memory and task-negative effects depend on dissociable neural mechanisms and likely reflect distinct cognitive processes. The relationship between task-negative effects and memory performance in the older group might reflect the sensitivity of these effects to variations in amount of age-related neuropathology. This article is part of a Special Issue entitled SI: Memory. PMID:25264353

  13. Personality Moderates the Interaction between Positive and Negative Daily Events Predicting Negative Affect and Stress

    PubMed Central

    Longua, Julie; DeHart, Tracy; Tennen, Howard; Armeli, Stephen

    2009-01-01

    A 30-day diary study examined personality moderators (neuroticism and extraversion) of the interaction between positive and negative daily events predicting daily negative affect and night-time stress. Multilevel analyses revealed positive daily events buffered the effect of negative daily events on negative affect for individuals low in neuroticism and individuals high in extraversion, but not for individuals high in neuroticism or individuals low in extraversion. Positive daily events also buffered the effect of negative daily events on that night’s stress, but only for participants low in neuroticism. As such, this research linked today’s events to tonight’s stressfulness. This study advances our understanding of how neuroticism and extraversion influence within-person associations between positive and negative events predicting negative affect and stress. PMID:20161239

  14. GDC-0941 and Cisplatin in Treating Patients With Androgen Receptor-Negative Triple Negative Metastatic Breast Cancer

    ClinicalTrials.gov

    2015-08-17

    Estrogen Receptor Negative Breast Cancer; Human Epidermal Growth Factor 2 Negative Carcinoma of Breast; Triple Negative Breast Cancer; Recurrent Breast Cancer; Stage IV Breast Cancer; Triple-negative Breast Cancer

  15. Negative transfer problem in neural networks

    NASA Astrophysics Data System (ADS)

    Abunawass, Adel M.

    1992-07-01

    Harlow, 1949, observed that when human subjects were trained to perform simple discrimination tasks over a sequence of successive training sessions (trials), their performance improved as a function of the successive sessions. Harlow called this phenomena `learning-to- learn.' The subjects acquired knowledge and improved their ability to learn in future training sessions. It seems that previous training sessions contribute positively to the current one. Abunawass & Maki, 1989, observed that when a neural network (using the back-propagation model) is trained over successive sessions, the performance and learning ability of the network degrade as a function of the training sessions. In some cases this leads to a complete paralysis of the network. Abunawass & Maki called this phenomena the `negative transfer' problem, since previous training sessions contribute negatively to the current one. The effect of the negative transfer problem is in clear contradiction to that reported by Harlow on human subjects. Since the ability to model human cognition and learning is one of the most important goals (and claims) of neural networks, the negative transfer problem represents a clear limitation to this ability. This paper describes a new neural network sequential learning model known as Adaptive Memory Consolidation. In this model the network uses its past learning experience to enhance its future learning ability. Adaptive Memory Consolidation has led to the elimination and reversal of the effect of the negative transfer problem. Thus producing a `positive transfer' effect similar to Harlow's learning-to-learn phenomena.

  16. The generality of negative hierarchically restrictive behaviours.

    PubMed

    Brown, Jennie; Trafimow, David; Gregory, W Larry

    2005-03-01

    Previous research has shown that when an actor engages in a negative hierarchically restrictive behaviour, a strong correspondent trait attribution is made and this behaviour is expected to generalize across situations (Trafimow, 2001). This paper discusses three experiments that examined the effects of extreme situations and perceived morality of the actor on the way in which participants make trait attributions, and the extent to which those behaviours are expected to generalize to other situations. Findings from Experiments 1 and 2 indicate that even negative hierarchically restrictive behaviours do not always lead to strong correspondent inferences if the situation in which the initial behaviour was performed was sufficiently extreme. Experiment 3 served to support these findings and cleared up questions from the first two experiments. Findings supported the hypothesis that some situations inhibit negative trait attributions and behaviour generalizations. Furthermore, findings indicate that the perception of the morality of the actor determines whether or not a negative hierarchically restrictive behaviour will lead to a negative trait attribution and generalization. PMID:15901388

  17. Extracted current saturation in negative ion sources

    SciTech Connect

    Mochalskyy, S.; Lifschitz, A. F.; Minea, T.

    2012-06-01

    The extraction of negatively charged particles from a negative ion source is one of the crucial issues in the development of the neutral beam injector system for future experimental reactor ITER. Full 3D electrostatic particle-in-cell Monte Carlo collision code - ONIX [S. Mochalskyy et al., Nucl. Fusion 50, 105011 (2010)] - is used to simulate the hydrogen plasma behaviour and the extracted particle features in the vicinity of the plasma grid, both sides of the aperture. It is found that the contribution to the extracted negative ion current of ions born in the volume is small compared with that of ions created at the plasma grid walls. The parametric study with respect to the rate of negative ions released from the walls shows an optimum rate. Beyond this optimum, a double layer builds-up by the negative ion charge density close to the grid aperture surface reducing thus extraction probability, and therefore the extracted current. The effect of the extraction potential and magnetic field magnitudes on the extraction is also discussed. Results are in good agreement with available experimental data.

  18. Negative obstacle detection by thermal signature

    NASA Technical Reports Server (NTRS)

    Matthies, Larry; Rankin, A.

    2003-01-01

    Detecting negative obstacles (ditches, potholes, and other depressions) is one of the most difficult problems in perception for autonomous, off-road navigation. Past work has largely relied on range imagery, because that is based on the geometry of the obstacle, is largely insensitive to illumination variables, and because there have not been other reliable alternatives. However, the visible aspect of negative obstacles shrinks rapidly with range, making them impossible to detect in time to avoid them at high speed. To relive this problem, we show that the interiors of negative obstacles generally remain warmer than the surrounding terrain throughout the night, making thermal signature a stable property for night-time negative obstacle detection. Experimental results to date have achieved detection distances 45% greater by using thermal signature than by using range data alone. Thermal signature is the first known observable with potential to reveal a deep negative obstacle without actually seeing far into it. Modeling solar illumination has potential to extend the usefulness of thermal signature through daylight hours.

  19. [Mutual inhibition between positive and negative emotions].

    PubMed

    Shimokawa, A

    1994-02-01

    The purpose of this study is to examine the relationship between positive and negative emotions. In study 1, 62 emotional items were selected in order to measure subjective emotional experiences. In study 2, comics, photos and poems were randomly presented to 1,220 college students to induce emotion. Subjects were asked to rate their momentary emotional intensity on two set of 5-point scales (general emotional intensity scale and 62 specific emotional intensity scale). In analysis 1, positive correlations were suggested between general emotional intensity scale and some of the specific emotional intensity scales which were activated by stimuli. In analysis 2, 10 positive and 10 negative emotional items were extracted from 62 items by factor analysis. In analysis 3, 4 and 5, it became clear that the distribution of frequency of correlations of 10 positive x 10 negative items changed according to the general emotional intensity scale. That is, from low to moderate levels of GEIS, the two kinds of emotion had no or slightly positive correlation, but at high level they became to be negatively correlated. From the facts described above, it is concluded that positive and negative emotions is not always independent, but show mutual inhibition in case of high intensity level of one of each emotions. PMID:8201808

  20. Technology of Manufacture of the Negative Matrices for Linear Fresnel Lenses

    NASA Astrophysics Data System (ADS)

    Lapshin, V. V.; Zakharevich, E. M.; Grubyy, S. V.

    2016-04-01

    This article describes the main structural features of negative matrices which are intended for the production of positive copies of linear Fresnel lenses. Linear lenses are used in a space solar energy industry as solar concentrators in the photovoltaic modules. The article covers the essential requirements which are placed on the equipment and technology for the production of such matrices.

  1. Bringing in the negative reinforcements: the avoidance feedback-related negativity.

    PubMed

    Crowley, Michael J; Wu, Jia; Bailey, Christopher A; Mayes, Linda C

    2009-11-25

    The feedback-related negativity (FRN) is an event-related potential thought to reflect a reward prediction error, when an outcome is worse than expected. Behavior motivated by the avoidance of negative outcomes is sustained through negative reinforcement processes. Escaping or avoiding a negative outcome may be successful or not, resulting in an analogous situation to that which elicits the FRN. We observed that when expected avoidance of an aversive outcome fails to occur, there occurs a negative deflection in the frontocentral event-related potential at approximately 350 ms, but with a slow wave following. We suggest that the FRN may be considered an index of a broader class of reward-based learning that also includes avoiding negative outcomes as well as expecting positive ones. PMID:19829164

  2. Carrier heating and negative photoconductivity in graphene

    SciTech Connect

    Heyman, J. N.; Stein, J. D.; Kaminski, Z. S.; Banman, A. R.; Massari, A. M.; Robinson, J. T.

    2015-01-07

    We investigated negative photoconductivity in graphene using ultrafast terahertz techniques. Infrared transmission was used to determine the Fermi energy, carrier density, and mobility of p-type chemical vapor deposition graphene samples. Time-resolved terahertz photoconductivity measurements using a tunable mid-infrared pump probed these samples at photon energies between 0.35 eV and 1.55 eV, approximately one-half to three times the Fermi energy of the samples. Although interband optical transitions in graphene are blocked for pump photon energies less than twice the Fermi energy, we observe negative photoconductivity at all pump photon energies investigated, indicating that interband excitation is not required to observe this effect. Our results are consistent with a thermalized free-carrier population that cools by electron-phonon scattering, but are inconsistent with models of negative photoconductivity based on population inversion.

  3. Negative coupled inductors for polyphase choppers

    NASA Technical Reports Server (NTRS)

    Jamieson, Robert S. (Inventor)

    1984-01-01

    A technique for negatively coupling the outputs of polyphase choppers is disclosed, wherein the output inductance of each phase is divided into two windings, and each winding is negatively coupled to a corresponding winding of a neighboring phase. In a preferred embodiment for a three-phase chopper circuit, the output inductance of phase A is divided into windings 100 and 102, the output inductance of phase B is divided into windings 110 and 112, and the output inductance of phase C is divided into windings 120 and 122. Pairs of windings 100 and 110, 112 and 120, and 102 and 122 are respectively disposed in transformers arranged for negatively coupling the windings of each pair.

  4. Classical fluids of negative heat capacity

    SciTech Connect

    Landsberg, P.T.; Woodard, R.P.

    1992-06-01

    It is shown that new parameters X can be defined such that the heat capacity C{sub X} {equivalent_to} T({partial_derivative}S/{partial_derivative}T)X is negative, even when the canonical ensemble (i.e. at fixed T = ({partial_derivative}U/{partial_derivative}S) and Y {ne} X) is stable. As examples we treat black body radiation and general gas systems with nonsingular {kappa}{sub T}. For the case of a simple ideal gas we even exhibit an apparatus which enforces a constraint X(p,V) = const. that makes C{sub X} < 0. Since it is possible to invent constraints for which canonically stable systems have negative heat capacity we speculate that it may also be possible to infer the statistical mechanics of canonically unstable systems - for which even the traditional heat capacities are negative - by imposing constraints that stabilize the associated, inoncanonical ensembles.

  5. Classical fluids of negative heat capacity

    SciTech Connect

    Landsberg, P.T. . Faculty of Mathematical Studies); Woodard, R.P. . Dept. of Physics)

    1992-06-01

    It is shown that new parameters X can be defined such that the heat capacity C{sub X} {equivalent to} T({partial derivative}S/{partial derivative}T)X is negative, even when the canonical ensemble (i.e. at fixed T = ({partial derivative}U/{partial derivative}S) and Y {ne} X) is stable. As examples we treat black body radiation and general gas systems with nonsingular {kappa}{sub T}. For the case of a simple ideal gas we even exhibit an apparatus which enforces a constraint X(p,V) = const. that makes C{sub X} < 0. Since it is possible to invent constraints for which canonically stable systems have negative heat capacity we speculate that it may also be possible to infer the statistical mechanics of canonically unstable systems - for which even the traditional heat capacities are negative - by imposing constraints that stabilize the associated, inoncanonical ensembles.

  6. Cells containing solvated electron lithium negative electrodes

    NASA Astrophysics Data System (ADS)

    Uribe, Francisco A.; Semkow, Krystyna W.; Sammells, Anthony F.

    1989-12-01

    This paper presents results obtained on cells based on solvated electron lithium negative electrodes, which may have application in high-energy-density secondary or reserve battery systems. The approach uses Li initially dissolved in liquid ammonia to give a solvated electron lithium/ammonia solution. This liquid negative active material is protected from direct contact with the liquid nonaqueous electrolyte in the positive electrode compartment by a lithium-intercalated electronically conducting ceramic membrane possessing Li(x)WoO2 composition with x values between 0.1 and 1.0. Depending upon initial lithium activity in the negative electrode compartments, the experimental cell was found to possess an initial open-circuit potential between 2.1 and 2.5 V.

  7. FTOC-Based Analysis of Negative Selection.

    PubMed

    Cunningham, Cody A; Teixeiro, Emma; Daniels, Mark A

    2016-01-01

    Potentially harmful T cell precursors are removed from the conventional T cell pool by negative selection. This process can involve the induction of apoptosis, anergy, receptor editing or deviation into a regulatory T cell lineage. As such this process is essential for the health of an organism through its contribution to central and peripheral tolerance. While a great deal is known about the process, the precise mechanisms that regulate negative selection are not clear. Furthermore, the signals that distinguish the different forms of negative selection are not fully understood. Numerous models exist with the potential to address these questions in vitro and in vivo. This chapter describes methods of fetal thymic organ culture designed to analyze the signals that determine these unique cell fates. PMID:26294405

  8. Tunable negative Poisson's ratio in hydrogenated graphene.

    PubMed

    Jiang, Jin-Wu; Chang, Tienchong; Guo, Xingming

    2016-09-21

    We perform molecular dynamics simulations to investigate the effect of hydrogenation on the Poisson's ratio of graphene. It is found that the value of the Poisson's ratio of graphene can be effectively tuned from positive to negative by varying the percentage of hydrogenation. Specifically, the Poisson's ratio decreases with an increase in the percentage of hydrogenation, and reaches a minimum value of -0.04 when the percentage of hydrogenation is about 50%. The Poisson's ratio starts to increase upon a further increase of the percentage of hydrogenation. The appearance of a minimum negative Poisson's ratio in the hydrogenated graphene is attributed to the suppression of the hydrogenation-induced ripples during the stretching of graphene. Our results demonstrate that hydrogenation is a valuable approach for tuning the Poisson's ratio from positive to negative in graphene. PMID:27536878

  9. A multimodal analysis of personal negativity.

    PubMed

    Furr, R M; Funder, D C

    1998-06-01

    This study examined how unhappiness and self-dissatisfaction are related to behavior, self-perception, social reputation, and the way one is treated by others. Varying in personal negativity (PN)--a composite of unhappiness, dissatisfaction with life, low self-esteem, and nonclinical depression--146 undergraduates (82 women and 64 men) engaged in 3 interactions. Participants' behavior and the behavior of their interaction partners was coded from videotapes. Personality ratings were obtained from participants and from 2 close acquaintances. PN was closely associated with maladaptive social interactions, negative behavioral responses by others, and a negative social reputation and self-image. Although women more clearly expressed PN behaviorally, men and women showed generally similar patterns of correlates. These results suggest that even subclinical levels of unhappiness and self-dissatisfaction may have important consequences. PMID:9654761

  10. Negative Electron Affinity Mechanism for Diamond Surfaces

    NASA Technical Reports Server (NTRS)

    Krainsky, I. L.; Asnin, V. M.

    1998-01-01

    The energy distribution of the secondary electrons for chemical vacuum deposited diamond films with Negative Electron Affinity (NEA) was investigated. It was found that while for completely hydrogenated diamond surfaces the negative electron affinity peak in the energy spectrum of the secondary electrons is present for any energy of the primary electrons, for partially hydrogenated diamond surfaces there is a critical energy above which the peak is present in the spectrum. This critical energy increases sharply when hydrogen coverage of the diamond surface diminishes. This effect was explained by the change of the NEA from the true type for the completely hydrogenated surface to the effective type for the partially hydrogenated surfaces.

  11. Above-threshold ionization of negative hydrogen

    NASA Astrophysics Data System (ADS)

    Nikolopoulos, L. A. A.; Lambropoulos, P.

    1997-10-01

    We present detailed calculations for two-and three-photon above-threshold ionization of the negative hydrogen ion. In addition to calculated values for partial wave amplitudes and phase shifts pertaining to recent experimental results [Xin Miao Zhao et al., Phys. Rev. Lett. 78, 1656 (1997)], we also address the question of the asymmetry of photoelectron angular distributions in ionization under elliptically polarized radiation, which has been studied experimentally in other negative ions [C. Blondel and C. Delsart, Laser Phys. 3, 3 (1993); Nucl. Instrum. Methods Phys. Res. B 79, 156 (1993); F. Dulieu, C. Blondel, and C. Delsart, J. Phys. B 28, 3861 (1995)].

  12. Negative refraction using Raman transitions and chirality

    SciTech Connect

    Sikes, D. E.; Yavuz, D. D.

    2011-11-15

    We present a scheme that achieves negative refraction with low absorption in far-off resonant atomic systems. The scheme utilizes Raman resonances and does not require the simultaneous presence of an electric-dipole transition and a magnetic-dipole transition near the same wavelength. We show that two interfering Raman tran-sitions coupled to a magnetic-dipole transition can achieve a negative index of refraction with low absorption through magnetoelectric cross-coupling. We confirm the validity of the analytical results with exact numerical simulations of the density matrix. We also discuss possible experimental implementations of the scheme in rare-earth metal atomic systems.

  13. Negative refraction using Raman transitions and chirality

    NASA Astrophysics Data System (ADS)

    Sikes, D. E.; Yavuz, D. D.

    2011-11-01

    We present a scheme that achieves negative refraction with low absorption in far-off resonant atomic systems. The scheme utilizes Raman resonances and does not require the simultaneous presence of an electric-dipole transition and a magnetic-dipole transition near the same wavelength. We show that two interfering Raman tran-sitions coupled to a magnetic-dipole transition can achieve a negative index of refraction with low absorption through magnetoelectric cross-coupling. We confirm the validity of the analytical results with exact numerical simulations of the density matrix. We also discuss possible experimental implementations of the scheme in rare-earth metal atomic systems.

  14. Real and imaginary negative binomial states

    NASA Astrophysics Data System (ADS)

    Liao, Jing; Wang, Xiaoguang; Wu, Ling-An; Pan, Shao-Hua

    2001-10-01

    The real and imaginary negative binomial states formed by a superposition of the negative binomial states are introduced. The sub-Poissonian statistics, Wigner function and squeezing properties of the real and imaginary states are studied in detail. The oscillatory character of the photon distribution due to the quantum interference between the two components is shown. Moreover, we find that these states are real and imaginary nonlinear Schrödinger cat states and give the corresponding ladder operator formalisms. We also discuss how to generate these general real quantum superposition states based on the intensity-dependent Jaynes-Cummings model.

  15. Negative Coulomb Drag in Double Bilayer Graphene.

    PubMed

    Li, J I A; Taniguchi, T; Watanabe, K; Hone, J; Levchenko, A; Dean, C R

    2016-07-22

    We report on an experimental measurement of Coulomb drag in a double quantum well structure consisting of bilayer-bilayer graphene, separated by few layer hexagonal boron nitride. At low temperatures and intermediate densities, a novel negative drag response with an inverse sign is observed, distinct from the momentum and energy drag mechanisms previously reported in double monolayer graphene. By varying the device aspect ratio, the negative drag component is suppressed and a response consistent with pure momentum drag is recovered. In the momentum drag dominated regime, excellent quantitative agreement with the density and temperature dependence predicted for double bilayer graphene is found. PMID:27494491

  16. Negative photoconductivity of InAs nanowires.

    PubMed

    Han, Yuxiang; Zheng, Xiao; Fu, Mengqi; Pan, Dong; Li, Xing; Guo, Yao; Zhao, Jianhua; Chen, Qing

    2016-01-14

    Negative photoconductivity is observed in InAs nanowires (NWs) without a surface defective layer. The negative photoconductivity is strongly dependent on the wavelength and intensity of the light, and is also sensitive to the environmental atmosphere. Two kinds of mechanisms are discerned to work together. One is related to gas adsorption, which is photodesorption of water molecules and photo-assisted chemisorption of O2 molecules. The other one can be attributed to the photogating effect introduced by the native oxide layer outside the NWs. PMID:26631367

  17. Negative electrodes for lithium cells and batteries

    DOEpatents

    Vaughey, John T.; Fransson, Linda M.; Thackeray, Michael M.

    2005-02-15

    A negative electrode is disclosed for a non-aqueous electrochemical cell. The electrode has an intermetallic compound as its basic structural unit with the formula M.sub.2 M' in which M and M' are selected from two or more metal elements including Si, and the M.sub.2 M' structure is a Cu.sub.2 Sb-type structure. Preferably M is Cu, Mn and/or Li, and M' is Sb. Also disclosed is a non-aqueous electrochemical cell having a negative electrode of the type described, an electrolyte and a positive electrode. A plurality of cells may be arranged to form a battery.

  18. GPM Solar Array Gravity Negated Deployment Testing

    NASA Technical Reports Server (NTRS)

    Penn, Jonathan; Johnson, Chris; Lewis, Jesse; Dear, Trevin; Stewart, Alphonso

    2014-01-01

    NASA Goddard Space Flight Center (GSFC) successfully developed a g-negation support system for use on the solar arrays of the Global Precipitation Measurement (GPM) Satellite. This system provides full deployment capability at the subsystem and observatory levels. In addition, the system provides capability for deployed configuration first mode frequency verification testing. The system consists of air pads, a support structure, an air supply, and support tables. The g-negation support system was used to support all deployment activities for flight solar array deployment testing.

  19. Negative transcriptional regulation in the Caulobacter flagellar hierarchy.

    PubMed Central

    Xu, H; Dingwall, A; Shapiro, L

    1989-01-01

    The Caulobacter crescentus flagellum is formed at a specific time in the cell cycle and its assembly requires the ordered expression of a large number of genes. These genes are controlled in a positive trans-acting hierarchy that reflects the order of assembly of the flagellum. Using plasmids carrying transcriptional fusions of either a neo or a lux reporter gene to the promoters of three flagellar genes representing different ranks in the hierarchy (the hook operon, a basal body gene flbN, and the flaO gene), we have measured the level of chimeric gene expression in 13 flagellar mutant backgrounds. Mutants in the hook operon or in basal body genes caused overproduction of both hook operon and basal body gene chimeric mRNAs, suggesting that negative regulation is superimposed on the positive trans-acting control for these early events in the flagellar hierarchy. Mutants in the structural genes and in genes involved in flagellar assembly had no effect on flaO expression, placing the flaO gene near the top of the hierarchy. However, flaO expression appears to be under negative control by two regulatory genes flaS and flaW. Negative control, as a response to the completion of specific steps in the assembly process, may be an important mechanism used by the cell to turn off flagellar gene expression once the gene product is no longer needed. Images PMID:2771950

  20. Examining the latent structure of negative symptoms: is there a distinct subtype of negative symptom schizophrenia?

    PubMed

    Blanchard, Jack J; Horan, William P; Collins, Lindsay M

    2005-09-15

    Negative symptoms have emerged as a replicable factor of symptomatology within schizophrenia. Although rating scales provide assessments along dimensions of severity, categorization into a negative symptom subtype is typically conducted. A categorical view of negative symptoms is best reflected in the proposal that enduring, primary negative symptoms, or deficit symptoms, reflect a distinct subtype of schizophrenia . Despite an accumulation of findings that support a categorical conceptualization, the data are also consistent with a dimensional-only model where negative symptom subtypologies simply reflect an extreme on a continuum of severity. Using taxometric statistical methods , the present study examined whether a taxonic, or latent class, model best describes negative symptoms in a sample of 238 schizophrenia patients. In order to obtain more stable estimates of symptoms, ratings on the Scale for the Assessment of Negative Symptoms [Andreasen, N.C., 1982. Negative symptoms in schizophrenia: Definition and reliability. Arch. Gen. Psychiatry 39, 784-788.] were averaged across two assessments over a 6-month period. Two taxometric methods, maximum covariance analysis (MAXCOV) and mean above minus below a cut (MAMBAC) identified a latent class or taxon with a base rate of approximately 28-36%. Members of the negative symptom taxon differed from the nontaxon class in that taxon members were more likely to be male and demonstrated poorer social functioning. Taxon and nontaxon schizophrenia patients did not differ in psychotic or affective symptoms. The findings converge to provide support for a categorical view of negative symptoms. Further research is required to replicate the present taxonic findings and to examine characteristics (including possible etiological factors) associated with this negative symptom taxon. PMID:15916881

  1. Negative ion-uranium hexafluoride charge transfer reactions

    NASA Astrophysics Data System (ADS)

    Streit, Gerald E.; Newton, T. W.

    1980-10-01

    The flowing afterglow technique has been used to study the process of charge transfer from selected negative ions (F-, Cl-, Br-, I-, SF6-) to UF6. The sole ionic product in all cases was observed to be UF6-. Data analysis was complicated by an unexpected coupling of chemical and diffusive ion loss processes when UF6- product ions were present. The rate coefficients for the charge transfer processes are (k in 10-9 cm3 molecule-1 s-1) F-, 1.3; Cl-, 1.1; Br-, 0.93; I-, 0.77; and SF6-, 0.69. The rate constants agree quite well with the classical Langevin predictions.

  2. Burton-Roberts on Presupposition and Negation.

    ERIC Educational Resources Information Center

    Seuren, Pieter A. M.

    1990-01-01

    A critical analysis explores the strictly logical aspects and pragmatic claims of a presupposition and negation theory (Burton-Roberts, 1989). Other clearly relevant facts, not previously considered, are used to show that the theory preempted empirical issues on invalid a priori grounds. (23 references) (Author/CB)

  3. Revisiting the gram-negative lipoprotein paradigm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The processing of lipoproteins (lpps) in Gram-negative bacteria is generally considered to be an essential pathway. Mature lipoproteins in these bacteria are triacylated, with the final fatty acid addition performed by Lnt, an apolipoprotein n-acyltransferase. The mature lipoproteins are then sorted...

  4. Attribution of Negative Intention in Williams Syndrome

    ERIC Educational Resources Information Center

    Godbee, Kali; Porter, Melanie A.

    2013-01-01

    People with Williams syndrome (WS) are said to have sociable and extremely trusting personalities, approaching strangers without hesitation. This study investigated whether people with WS are less likely than controls to attribute negative intent to others when interpreting a series of ambiguous pictures. This may, at least partially, explain…

  5. Negative running can prevent eternal inflation

    SciTech Connect

    Kinney, William H.; Freese, Katherine E-mail: ktfreese@umich.edu

    2015-01-01

    Current data from the Planck satellite and the BICEP2 telescope favor, at around the 2 σ level, negative running of the spectral index of curvature perturbations from inflation. We show that for negative running α < 0, the curvature perturbation amplitude has a maximum on scales larger than our current horizon size. A condition for the absence of eternal inflation is that the curvature perturbation amplitude always remain below unity on superhorizon scales. For current bounds on n{sub S} from Planck, this corresponds to an upper bound of the running α < −9 × 10{sup −5}, so that even tiny running of the scalar spectral index is sufficient to prevent eternal inflation from occurring, as long as the running remains negative on scales outside the horizon. In single-field inflation models, negative running is associated with a finite duration of inflation: we show that eternal inflation may not occur even in cases where inflation lasts as long as 10{sup 4} e-folds.

  6. The Contrast Theory of Negative Input.

    ERIC Educational Resources Information Center

    Saxton, Matthew

    1997-01-01

    Presents an alternative definition of negative evidence, based on the idea that the unique discourse structure created in the juxtaposition of child error and adult correct form can reveal the child in contrast or conflict between the two forms. Findings reveal that children reproduced the correct irregular model more often and persisted with…

  7. Overcoming Graduate Students' Negative Perceptions of Statistics

    ERIC Educational Resources Information Center

    Lalayants, Marina

    2012-01-01

    Although there has been some attention in the literature to such issues as students' attitudes toward statistics, instructors are still constantly faced with the challenge to engage students; understand their perceptions, motivations, and interests; and deal with their reluctance and negative attitudes toward the field of statistics. The purpose…

  8. The Negative "Aspects" of Children's Writing.

    ERIC Educational Resources Information Center

    Gale, Irma F.; Boisvert, Louis

    This study of the negative side of children's writing utilized an experimental group and a control group equalized according to sex and the results of the language sub-tests of the Stanford Achievement Tests. Students wrote two 1,000 word composition samples, one during the first month of the study and one during the ninth month. The purposes of…

  9. Estimating the Probability of Negative Events

    ERIC Educational Resources Information Center

    Harris, Adam J. L.; Corner, Adam; Hahn, Ulrike

    2009-01-01

    How well we are attuned to the statistics of our environment is a fundamental question in understanding human behaviour. It seems particularly important to be able to provide accurate assessments of the probability with which negative events occur so as to guide rational choice of preventative actions. One question that arises here is whether or…

  10. Comprehension of action negation involves inhibitory simulation.

    PubMed

    Foroni, Francesco; Semin, Gün R

    2013-01-01

    Previous research suggests that action language is comprehended by activating the motor system. We report a study, investigating a critical question in this research field: do negative sentences activate the motor system? Participants were exposed to sentences in the affirmation and negation forms while the zygomatic muscle activity on the left side of the face was continuously measured (Electromyography technique: EMG). Sentences were descriptions of emotional expressions that mapped either directly upon the zygomatic muscle (e.g., "I am smiling") or did not (e.g., "I am frowning"). Reading sentences involving the negation of the activity of a specific muscle (zygomatic major-"I am not smiling") is shown to lead to the inhibition of this muscle. Reading sentences involving the affirmative form instead ("I am smiling") leads to the activation of zygomatic mucle. In contrast, sentences describing an activity that is irrelevant to the zygomatic muscle (e.g., "I am frowning" or "I am not frowning") produce no muscle activity. These results extend the range of simulation models to negation and by implication to an abstract domain. We discuss how this research contributes to the grounding of abstract and concrete concepts. PMID:23754996

  11. The negative affect hypothesis of noise sensitivity.

    PubMed

    Shepherd, Daniel; Heinonen-Guzejev, Marja; Heikkilä, Kauko; Dirks, Kim N; Hautus, Michael J; Welch, David; McBride, David

    2015-05-01

    Some studies indicate that noise sensitivity is explained by negative affect, a dispositional tendency to negatively evaluate situations and the self. Individuals high in such traits may report a greater sensitivity to other sensory stimuli, such as smell, bright light and pain. However, research investigating the relationship between noise sensitivity and sensitivity to stimuli associated with other sensory modalities has not always supported the notion of a common underlying trait, such as negative affect, driving them. Additionally, other explanations of noise sensitivity based on cognitive processes have existed in the clinical literature for over 50 years. Here, we report on secondary analyses of pre-existing laboratory (n = 74) and epidemiological (n = 1005) data focusing on the relationship between noise sensitivity to and annoyance with a variety of olfactory-related stimuli. In the first study a correlational design examined the relationships between noise sensitivity, noise annoyance, and perceptual ratings of 16 odors. The second study sought differences between mean noise and air pollution annoyance scores across noise sensitivity categories. Results from both analyses failed to support the notion that, by itself, negative affectivity explains sensitivity to noise. PMID:25993104

  12. Negative mechanistic reasoning in medical intervention assessment.

    PubMed

    Jerkert, Jesper

    2015-12-01

    Traditionally, mechanistic reasoning has been assigned a negligible role in standard EBM (evidence-based medicine) literature, although some recent authors have argued for an upgrade. Even so, the mechanistic reasoning that has received attention has almost exclusively been positive--both in an epistemic sense of claiming that there is a mechanistic chain and in a health-related sense of there being claimed benefits for the patient. Negative mechanistic reasoning has been neglected, both in the epistemic and in the health-related sense. I distinguish three main types of negative mechanistic reasoning and subsume them under a new definition of mechanistic reasoning in the context of assessing medical interventions. This definition is wider than a previous suggestion in the literature. Each negative type corresponds to a range of evidential strengths, and it is argued that there are differences with respect to typical evidential strengths. The variety of negative mechanistic reasoning should be acknowledged in EBM, and it presents a serious challenge to proponents of so-called medical hierarchies of evidence. PMID:26597869

  13. A Hidden Case of Negative Amortization.

    ERIC Educational Resources Information Center

    Waits, Bert K.; Demana, Franklin

    1990-01-01

    The rule of 78 is used by banks and loan companies to compute the amounts due when installment loans are paid early. Describes an unexpected case of negative amortization when the rule is applied. Presents an actual problem and discusses the case. (YP)

  14. Negative Impacts of High-Stakes Testing

    ERIC Educational Resources Information Center

    Minarechová, Michaela

    2012-01-01

    High-stakes testing is not a new phenomenon in education. It has become part of the education system in many countries. These tests affect the school systems, teachers, students, politicians and parents, whether that is in a positive or negative sense. High-stakes testing is associated with concepts such as a school's accountability, funding…

  15. Negative Refraction experiments in Photonic Crystal prisms

    NASA Astrophysics Data System (ADS)

    Vodo, Plarenta; Parimi, Patanjali. V.; Lu, Wentao. T.; di Gennaro, Emiliano; Sridhar, Srinivas

    2004-03-01

    We have experimentally demonstrated negative refraction in metallic photonic crystal (PC) prisms [1]. The refracted fields in the parallel plate waveguide (PPW) are measured by an automated dipole antenna, which scans the desired area, while the free space (FS) measurements, performed in a anechoic chamber, are measured by a rectangular X-band horn that swings in an arc in far field area. Both TE and TM excitation modes are used in FS experiments. Numerical calculations of the band structure and equi-frequency surface simulations are used to determine frequency regions of negative refraction of the triangular lattice PC. Angle of refraction determined by theoretical simulations and experimental results, are in exceptional good agreement, yielding the negative refraction index. FS and PPW refraction experimental results agree remarkably with simulations. 1. "Negative Refraction and Left-handed electromagnetism in Microwave Photonic Crystals", P.V Parimi, W.T Lu, P.Vodo J. Sokoloff and S.Sridhar, cond-mat/0306109 (2003)

  16. Negative Electrode For An Alkaline Cell

    DOEpatents

    Coco, Isabelle; Cocciantelli, Jean-Michel; Villenave, Jean-Jacques

    1998-07-14

    The present invention concerns a negative electrode for an alkaline cell, comprising a current collector supporting a paste containing an electrochemically active material and a binder, characterized in that said binder is a polymer containing hydrophilic and hydrophobic groups, said polymer being selected from an acrylic homopolymer, copolymer and terpolymer, an unsaturated organic acid copolymer and an unsaturated acid anhydride copolymer.

  17. Pull Out Negativity by Its Roots.

    ERIC Educational Resources Information Center

    DuFour, Rick; Burnette, Becky

    2002-01-01

    Principals are well-positioned to cultivate their schools' cultures. They must remain vigilant in rooting out the beginnings of negative culture, including such teacher attitudes and behaviors as not feeling responsible for student learning, preferring to work alone, wanting to protect their territory, and focusing on activity rather than results.…

  18. L2 Negation Constructions at Work

    ERIC Educational Resources Information Center

    Eskildsen, Soren W.

    2012-01-01

    This article explores the usage- and exemplar-based roots of second language (L2) negation construction learning. Based on two longitudinal case studies involving two adult L2 English learners and a corpus of 63 three-hour sessions of recorded classroom interactions, the study shows that L2 learning follows the predictions of usage-based models of…

  19. Further Conceptualization of Explanation in Negative Messages.

    ERIC Educational Resources Information Center

    Limaye, Mohan R.

    1997-01-01

    Makes two suggestions for presentation in the classroom and in textbooks of business communication regarding explanation in negative messages: (1) providing a reasonable explanation is the sender's moral obligation, and receiving such explanation is a natural right of the target; and (2) explanation should be presented on two levels: general and…

  20. Challenging Negative Perceptions of Black Teachers

    ERIC Educational Resources Information Center

    Milner, H. Richard

    2012-01-01

    In this article, the author focuses on a case study of an African-American teacher's perceptions about teaching and instructional practices in an urban middle school, Bridge Middle School. He provides a counter to some negative conceptions of Black teachers in general through a focus on this teacher: the way she thinks about her roles and…

  1. Negative Capacitance in a Ferroelectric Capacitor

    NASA Astrophysics Data System (ADS)

    Khan, Asif; Chatterjee, Korok; Wang, Brian; Drapcho, Steven; You, Long; Serrao, Claudy; Bakaul, Saidur; Ramesh, Ramamoorthy; Salahuddin, Sayeef; UC Berkeley Team

    The Boltzmann distribution of electrons poses a fundamental barrier to lowering energy dissipation in conventional electronics, often termed as Boltzmann Tyranny. Negative capacitance in ferroelectric materials, which stems from the stored energy of phase transition, could provide a solution, but a direct measurement of negative capacitance has so far been elusive. Here we demonstrate the negative differential capacitance in an epitaxial ferroelectric film, by constructing a simple R-C network and monitoring the voltage dynamics across the ferroelectric capacitor. When a voltage pulse is applied, the voltage across the ferroelectric capacitor is found to be decreasing with time-in exactly the opposite direction to which voltage for a regular capacitor should change. The results are analyzed on the basis of the Landau-Khalatnikov equation, which shows that as the ferroelectric polarization switches its direction, it passes through the unstable negative capacitance region. Analysis of this behavior from a capacitor presents an unprecedented insight into the intrinsic energy profile of the ferroelectric material.

  2. The Negative Affect Hypothesis of Noise Sensitivity

    PubMed Central

    Shepherd, Daniel; Heinonen-Guzejev, Marja; Heikkilä, Kauko; Dirks, Kim N.; Hautus, Michael J.; Welch, David; McBride, David

    2015-01-01

    Some studies indicate that noise sensitivity is explained by negative affect, a dispositional tendency to negatively evaluate situations and the self. Individuals high in such traits may report a greater sensitivity to other sensory stimuli, such as smell, bright light and pain. However, research investigating the relationship between noise sensitivity and sensitivity to stimuli associated with other sensory modalities has not always supported the notion of a common underlying trait, such as negative affect, driving them. Additionally, other explanations of noise sensitivity based on cognitive processes have existed in the clinical literature for over 50 years. Here, we report on secondary analyses of pre-existing laboratory (n = 74) and epidemiological (n = 1005) data focusing on the relationship between noise sensitivity to and annoyance with a variety of olfactory-related stimuli. In the first study a correlational design examined the relationships between noise sensitivity, noise annoyance, and perceptual ratings of 16 odors. The second study sought differences between mean noise and air pollution annoyance scores across noise sensitivity categories. Results from both analyses failed to support the notion that, by itself, negative affectivity explains sensitivity to noise. PMID:25993104

  3. Intonational Prominence on Negatives in English.

    ERIC Educational Resources Information Center

    Yaeger-Dror, Malcah L.

    1985-01-01

    Describes a study done to determine which intonational parameters are most important to the meaning being conveyed within different social settings. Defines the factors that appear to influence the use of pitch and/or intensity prominence on negative words. Found that, in many situations, interactional rules take precedence over linguistic rules.…

  4. Quantum Rigidity of Negatively Curved Manifolds

    NASA Astrophysics Data System (ADS)

    Chirvasitu, Alexandru

    2016-05-01

    We show that an isometric action of a compact quantum group on the underlying geodesic metric space of a compact connected Riemannian manifold ( M, g) with strictly negative curvature is automatically classical, in the sense that it factors through the action of the isometry group of ( M, g). This partially answers a question by D. Goswami.

  5. Error-Related Psychophysiology and Negative Affect

    ERIC Educational Resources Information Center

    Hajcak, G.; McDonald, N.; Simons, R.F.

    2004-01-01

    The error-related negativity (ERN/Ne) and error positivity (Pe) have been associated with error detection and response monitoring. More recently, heart rate (HR) and skin conductance (SC) have also been shown to be sensitive to the internal detection of errors. An enhanced ERN has consistently been observed in anxious subjects and there is some…

  6. Stress and Coping Activity: Reframing Negative Thoughts

    ERIC Educational Resources Information Center

    Hughes, Jamie S.; Gourley, Mary K.; Madson, Laura; Le Blanc, Katya

    2011-01-01

    Stress management and coping techniques are not only relevant in many psychology courses but also personally relevant for undergraduate students. In this article, the authors describe an activity designed to provide students with practice evaluating and challenging negative self-talk. Students responded to scenarios individually, were paired with…

  7. Negative Effects from Psychological Treatments: A Perspective

    ERIC Educational Resources Information Center

    Barlow, David H.

    2010-01-01

    The author offers a 40-year perspective on the observation and study of negative effects from psychotherapy or psychological treatments. This perspective is placed in the context of the enormous progress in refining methodologies for psychotherapy research over that period of time, resulting in the clear demonstration of positive effects from…

  8. Clausal Architecture and Sentential Negation in Slavic

    ERIC Educational Resources Information Center

    Tsurska, Olena Anatoliyivna

    2010-01-01

    This study presents a comparative analysis of the clausal architecture and sentential negation in East (Russian, Ukrainian, and Belarusian), West, Polish, Czech, Slovak, and Upper and Lower Sorbian), and South (Bulgarian, Macedonian, Bosnian/Croatian/Serbian, and Slovenian) languages. Using the Minimalist Program, I analyze the syntactic structure…

  9. Negative Bodily Self in Suicide Attempters

    ERIC Educational Resources Information Center

    Orbach, Israel; Gilboa-Schechtman, Eva; Sheffer, Amir; Meged, Sorin; Har-Even, Dov; Stein, Daniel

    2006-01-01

    In the present study we investigated the relationship between suicidal behavior and aspects of bodily perception and parental care. Measures of bodily perception included measures of tactile sensitivity, body attitudes, and body experiences. Measures of parental care included parental bonding, negative and positive touch, and early maltreatment.…

  10. When Depressive Cognitions Reflect Negative Realities.

    ERIC Educational Resources Information Center

    Krantz, Susan E.

    The cognitive model of depression postulates that the depressed individual's cognitions are not only negative, but erroneous and impervious to information from the environment. However, the valence of that information ultimately determines whether those cognitions are impervious or merely receptive. The actual life circumstances of the depressed…

  11. Proactive and Retroactive Effects of Negative Suggestion

    ERIC Educational Resources Information Center

    Brown, Alan S.; Brown, Christine M.; Mosbacher, Joy L.; Dryden, W. Erich

    2006-01-01

    The negative effects of false information presented either prior to (proactive interference; PI) or following (retroactive interference; RI) true information was examined with word definitions (Experiment 1) and trivia facts (Experiment 2). Participants were explicitly aware of which information was true and false when shown, and true-false…

  12. Negativity Bias in Attribution of External Agency

    ERIC Educational Resources Information Center

    Morewedge, Carey K.

    2009-01-01

    This research investigated whether people are more likely to attribute events to external agents when events are negative rather than neutral or positive. Participants more often believed that ultimatum game partners were humans rather than computers when the partners offered unusually unfavorable divisions than unusually favorable divisions…

  13. Action Learning, Performativity and Negative Capability

    ERIC Educational Resources Information Center

    Edmonstone, John

    2016-01-01

    The paper examines the concept of negative capability as a human capacity for containment and contrasts it with well-valued positive capability as expressed through performativity in organisations and society. It identifies the problem of dispersal--the complex ways we behave in order to avoid the emotional challenges of living with uncertainty.…

  14. Is Cross-Race Mentoring a Negative?

    ERIC Educational Resources Information Center

    Dolan, Thomas G.

    2007-01-01

    The author discusses cross-race mentoring and examines whether this is necessarily a negative. Here, he presents the opinions of one African-American female Ph.D., two Hispanic female Ph.D.s, and one Hispanic male graduate student, who offer varied perspectives. Ten points are presented: (1) 1. Cross-race mentoring requires extra sensitivity; (2)…

  15. Suicidal Fantasies and Positive/Negative Effects.

    ERIC Educational Resources Information Center

    Fouts, Gregory; Norrie, Janice

    This study attempted to provide some initial normative data to help professionals and researchers to distinguish between playful and stimulating suicidal fantasies as opposed to serious and compulsive thoughts and behaviours characterized by negative affects. It is argued that the former is a natural consequence of cognitive development, the entry…

  16. [Psychopathological aspects of negative symptoms in schizophrenia].

    PubMed

    Cermolacce, M; Belzeaux, R; Pringuey, D; Adida, M; Azorin, J-M

    2015-12-01

    During the past ten years, research on schizophrenia has witnessed a clear emphasis on studies based on negative symptoms. This interest can be explained in terms of diagnosis, specific treatment, functional prognosis and outcome issues. However, main current approaches consider negative symptoms from an operationalist view, which implies objective and atheoretical descriptions of clinical criteria, observed from a third person perspective. And the understanding of negative symptoms in schizophrenia, still a crucial issue of mental health, remains only partial. From a different perspective, psychopathology - and notably psychiatric phenomenology -, can provide a conceptual and clinical framework, taking into account subjective experience (first person perspective), based on a global understanding of the clinical situation lived by patients with schizophrenia. In the present review, we give a brief survey on the historical aspects of the description of negative symptoms. Then, we introduce the clinical contributions raised by clinical phenomenology. We principally develop Minkowski's notion of loss of vital contact, and Blankenburg's notion of loss of natural evidence. Then we highlight the current debates which are discussed and explored in contemporary psychopathology. In conclusion, we discuss the possible articulation between objective and subjective approaches, in order to better understand pauci-symptomatic forms of schizophrenia. PMID:26776395

  17. [Negative symptoms of schizophrenia: historical aspects].

    PubMed

    Pringuey, D; Paquin, N; Cherikh, F; Giordana, B; Belzeaux, R; Cermolacce, M; Adida, M; Azorin, J-M

    2015-12-01

    The history of negative symptoms of schizophrenia rises early days of medicine in clinical and pathophysiological differences between positive and negative and their complex joint. Forming a set of typical core of symptoms, and some feature of a syndrome belonging to a specific pathophysiological mechanism, negative symptoms of schizophrenia emerge from old descriptions of clinical pictures, related to the overall look of madness, the heart of alienation, a central sign of early dementia, gradually more precisely describing the strange nature of the autistic withdrawal and schizophrenic apragmatism. At therapeutic era, negative symptoms have taken over the positive symptoms to establish an operational criteria whose importance lies in the progressive severity of this clinical type and in their contribution to therapeutic resistance. Despite the efforts of modern typological classifications, this work rehabilitates the old concept of "unitary psychosis" by defining a common symptomatic core to multiple clinical forms of psychosis, combining deficit of emotional expression and avolition, meaning a native psychopathology and a pathophysiology possibly in a common final way, and calling the arrival of new treatment strategies. PMID:26776389

  18. Improvement of uniformity of the negative ion beams by tent-shaped magnetic field in the JT-60 negative ion source

    SciTech Connect

    Yoshida, Masafumi Hanada, Masaya; Kojima, Atsushi; Kashiwagi, Mieko; Akino, Noboru; Endo, Yasuei; Komata, Masao; Mogaki, Kazuhiko; Nemoto, Shuji; Ohzeki, Masahiro; Seki, Norikazu; Sasaki, Shunichi; Shimizu, Tatsuo; Terunuma, Yuto; Grisham, Larry R.

    2014-02-15

    Non-uniformity of the negative ion beams in the JT-60 negative ion source with the world-largest ion extraction area was improved by modifying the magnetic filter in the source from the plasma grid (PG) filter to a tent-shaped filter. The magnetic design via electron trajectory calculation showed that the tent-shaped filter was expected to suppress the localization of the primary electrons emitted from the filaments and created uniform plasma with positive ions and atoms of the parent particles for the negative ions. By modifying the magnetic filter to the tent-shaped filter, the uniformity defined as the deviation from the averaged beam intensity was reduced from 14% of the PG filter to ∼10% without a reduction of the negative ion production.

  19. Positive Effects of Talking about the Negative: Family Narratives of Negative Experiences and Preadolescents' Perceived Competence

    ERIC Educational Resources Information Center

    Marin, Kelly A.; Bohanek, Jennifer G.; Fivush, Robyn

    2008-01-01

    Family narratives about the past are an important context for the socialization of emotion, but relations between expression of negative emotion and children's emerging competence are conflicting. In this study, 24 middle-class two-parent families narrated a shared negative experience together and we examined the process (initiations and…

  20. Revisiting the Gram-Negative Lipoprotein Paradigm

    PubMed Central

    LoVullo, Eric D.; Wright, Lori F.; Isabella, Vincent; Huntley, Jason F.

    2015-01-01

    ABSTRACT The processing of lipoproteins (Lpps) in Gram-negative bacteria is generally considered an essential pathway. Mature lipoproteins in these bacteria are triacylated, with the final fatty acid addition performed by Lnt, an apolipoprotein N-acyltransferase. The mature lipoproteins are then sorted by the Lol system, with most Lpps inserted into the outer membrane (OM). We demonstrate here that the lnt gene is not essential to the Gram-negative pathogen Francisella tularensis subsp. tularensis strain Schu or to the live vaccine strain LVS. An LVS Δlnt mutant has a small-colony phenotype on sucrose medium and increased susceptibility to globomycin and rifampin. We provide data indicating that the OM lipoprotein Tul4A (LpnA) is diacylated but that it, and its paralog Tul4B (LpnB), still sort to the OM in the Δlnt mutant. We present a model in which the Lol sorting pathway of Francisella has a modified ABC transporter system that is capable of recognizing and sorting both triacylated and diacylated lipoproteins, and we show that this modified system is present in many other Gram-negative bacteria. We examined this model using Neisseria gonorrhoeae, which has the same Lol architecture as that of Francisella, and found that the lnt gene is not essential in this organism. This work suggests that Gram-negative bacteria fall into two groups, one in which full lipoprotein processing is essential and one in which the final acylation step is not essential, potentially due to the ability of the Lol sorting pathway in these bacteria to sort immature apolipoproteins to the OM. IMPORTANCE This paper describes the novel finding that the final stage in lipoprotein processing (normally considered an essential process) is not required by Francisella tularensis or Neisseria gonorrhoeae. The paper provides a potential reason for this and shows that it may be widespread in other Gram-negative bacteria. PMID:25755189

  1. Studies of transition states and radicals by negative ion photodetachment

    SciTech Connect

    Metz, R.B.

    1991-12-01

    Negative ion photodetachment is a versatile tool for the production and study of transient neutral species such as reaction intermediates and free radicals. Photodetachment of the stable XHY{sup {minus}} anion provides a direct spectroscopic probe of the transition state region of the potential energy surface for the neutral hydrogen transfer reaction X + HY {yields} XH + Y, where X and Y are halogen atoms. The technique is especially sensitive to resonances, which occur at a specific energy, but the spectra also show features due to direct scattering. We have used collinear adiabatic simulations of the photoelectron spectra to evaluate trail potential energy surfaces for the biomolecular reactions and have extended the adiabatic approach to three dimensions and used it to evaluate empirical potential energy surfaces for the I + Hl and Br + HI reactions. In addition, we have derived an empirical, collinear potential energy surface for the Br + HBr reaction that reproduces our experimental results and have extended this surface to three dimensions. Photodetachment of a negative ion can be also used to study neutral free radicals. We have studied the vibrational and electronic spectroscopy of CH{sub 2}NO{sub 2} by photoelectron spectroscopy of CH{sub 2}NO{sub 2}{sup {minus}}, determining the electron affinity of CH{sub 2}NO{sub 2}, gaining insight on the bonding of the {sup 2}B{sub 1} ground state and observing the {sup 2}A{sub 2} excited state for the first time. Negative ion photodetachment also provides a novel and versatile source of mass-selected, jet-cooled free radicals. We have studied the photodissociation of CH{sub 2}NO{sub 2} at 270, 235, and 208 nm, obtaining information on the dissociation products by measuring the kinetic energy release in the photodissociation.

  2. Is the negative glow plasma of a direct current glow discharge negatively charged?

    NASA Astrophysics Data System (ADS)

    Bogdanov, E. A.; Demidov, V. I.; Kudryavtsev, A. A.; Saifutdinov, A. I.

    2015-02-01

    A classic problem in gas discharge physics is discussed: what is the sign of charge density in the negative glow region of a glow discharge? It is shown that traditional interpretations in text-books on gas discharge physics that states a negative charge of the negative glow plasma are based on analogies with a simple one-dimensional model of discharge. Because the real glow discharges with a positive column are always two-dimensional, the transversal (radial) term in divergence with the electric field can provide a non-monotonic axial profile of charge density in the plasma, while maintaining a positive sign. The numerical calculation of glow discharge is presented, showing a positive space charge in the negative glow under conditions, where a one-dimensional model of the discharge would predict a negative space charge.

  3. Is the negative glow plasma of a direct current glow discharge negatively charged?

    SciTech Connect

    Bogdanov, E. A.; Saifutdinov, A. I.; Demidov, V. I.; Kudryavtsev, A. A.

    2015-02-15

    A classic problem in gas discharge physics is discussed: what is the sign of charge density in the negative glow region of a glow discharge? It is shown that traditional interpretations in text-books on gas discharge physics that states a negative charge of the negative glow plasma are based on analogies with a simple one-dimensional model of discharge. Because the real glow discharges with a positive column are always two-dimensional, the transversal (radial) term in divergence with the electric field can provide a non-monotonic axial profile of charge density in the plasma, while maintaining a positive sign. The numerical calculation of glow discharge is presented, showing a positive space charge in the negative glow under conditions, where a one-dimensional model of the discharge would predict a negative space charge.

  4. The positives of negative emotions: willingness to express negative emotions promotes relationships.

    PubMed

    Graham, Steven M; Huang, Julie Y; Clark, Margaret S; Helgeson, Vicki S

    2008-03-01

    Four studies support the hypothesis that expressing negative emotion is associated with positive relationship outcomes, including elicitation of support, building of new close relationships, and heightening of intimacy in the closest of those relationships. In Study 1, participants read vignettes in which another person was experiencing a negative emotion. Participants reported they would provide more help when the person chose to express the negative emotion. In Study 2, participants watched a confederate preparing for a speech. Participants provided more help to her when she expressed nervousness. In Study 3, self-reports of willingness to express negative emotions predicted having more friends, controlling for demographic variables and extraversion. In Study 4, self-reports of willingness to express negative emotion measured prior to arrival at college predicted formation of more relationships, greater intimacy in the closest of those relationships, and greater received support from roommates across participants' first semester of college. PMID:18272807

  5. Lotka's Law and Institutional Productivity.

    ERIC Educational Resources Information Center

    Kumar, Suresh; Sharma, Praveen; Garg, K. C.

    1998-01-01

    Examines the applicability of Lotka's Law, negative binomial distribution, and lognormal distribution for institutional productivity in the same way as it is to authors and their productivity. Results indicate that none of the distributions are applicable for institutional productivity in engineering sciences. (Author/LRW)

  6. Dominant negative autoregulation limits steady-state repression levels in gene networks.

    PubMed

    Semsey, Szabolcs; Krishna, Sandeep; Erdossy, János; Horváth, Péter; Orosz, László; Sneppen, Kim; Adhya, Sankar

    2009-07-01

    Many transcription factors repress transcription of their own genes. Negative autoregulation has been shown to reduce cell-cell variation in regulatory protein levels and speed up the response time in gene networks. In this work we examined transcription regulation of the galS gene and the function of its product, the GalS protein. We observed a unique operator preference of the GalS protein characterized by dominant negative autoregulation. We show that this pattern of regulation limits the repression level of the target genes in steady states. We suggest that transcription factors with dominant negative autoregulation are designed for regulating gene expression during environmental transitions. PMID:19429616

  7. Installation of spectrally selective imaging system in RF negative ion source

    NASA Astrophysics Data System (ADS)

    Ikeda, K.; Wünderlich, D.; Fantz, U.; Heinemann, B.; Kisaki, M.; Nagaoka, K.; Nakano, H.; Osakabe, M.; Tsumori, K.; Geng, S.; Kaneko, O.; Takeiri, Y.

    2016-02-01

    A spectrally selective imaging system has been installed in the RF negative ion source in the International Thermonuclear Experimental Reactor-relevant negative ion beam test facility ELISE (Extraction from a Large Ion Source Experiment) to investigate distribution of hydrogen Balmer-α emission (Hα) close to the production surface of hydrogen negative ion. We selected a GigE vision camera coupled with an optical band-path filter, which can be controlled remotely using high speed network connection. A distribution of Hα emission near the bias plate has been clearly observed. The same time trend on Hα intensities measured by the imaging diagnostic and the optical emission spectroscopy is confirmed.

  8. Effects of discharge chamber length on the negative ion generation in volume-produced negative hydrogen ion source

    SciTech Connect

    Chung, Kyoung-Jae; Jung, Bong-Ki; An, YoungHwa; Dang, Jeong-Jeung; Hwang, Y. S.

    2014-02-15

    In a volume-produced negative hydrogen ion source, control of electron temperature is essential due to its close correlation with the generation of highly vibrationally excited hydrogen molecules in the heating region as well as the generation of negative hydrogen ions by dissociative attachment in the extraction region. In this study, geometric effects of the cylindrical discharge chamber on negative ion generation via electron temperature changes are investigated in two discharge chambers with different lengths of 7.5 cm and 11 cm. Measurements with a radio-frequency-compensated Langmuir probe show that the electron temperature in the heating region is significantly increased by reducing the length of the discharge chamber due to the reduced effective plasma size. A particle balance model which is modified to consider the effects of discharge chamber configuration on the plasma parameters explains the variation of the electron temperature with the chamber geometry and gas pressure quite well. Accordingly, H{sup −} ion density measurement with laser photo-detachment in the short chamber shows a few times increase compared to the longer one at the same heating power depending on gas pressure. However, the increase drops significantly as operating gas pressure decreases, indicating increased electron temperatures in the extraction region degrade dissociative attachment significantly especially in the low pressure regime. It is concluded that the increase of electron temperature by adjusting the discharge chamber geometry is efficient to increase H{sup −} ion production as long as low electron temperatures are maintained in the extraction region in volume-produced negative hydrogen ion sources.

  9. Effects of discharge chamber length on the negative ion generation in volume-produced negative hydrogen ion source.

    PubMed

    Chung, Kyoung-Jae; Jung, Bong-Ki; An, YoungHwa; Dang, Jeong-Jeung; Hwang, Y S

    2014-02-01

    In a volume-produced negative hydrogen ion source, control of electron temperature is essential due to its close correlation with the generation of highly vibrationally excited hydrogen molecules in the heating region as well as the generation of negative hydrogen ions by dissociative attachment in the extraction region. In this study, geometric effects of the cylindrical discharge chamber on negative ion generation via electron temperature changes are investigated in two discharge chambers with different lengths of 7.5 cm and 11 cm. Measurements with a radio-frequency-compensated Langmuir probe show that the electron temperature in the heating region is significantly increased by reducing the length of the discharge chamber due to the reduced effective plasma size. A particle balance model which is modified to consider the effects of discharge chamber configuration on the plasma parameters explains the variation of the electron temperature with the chamber geometry and gas pressure quite well. Accordingly, H(-) ion density measurement with laser photo-detachment in the short chamber shows a few times increase compared to the longer one at the same heating power depending on gas pressure. However, the increase drops significantly as operating gas pressure decreases, indicating increased electron temperatures in the extraction region degrade dissociative attachment significantly especially in the low pressure regime. It is concluded that the increase of electron temperature by adjusting the discharge chamber geometry is efficient to increase H(-) ion production as long as low electron temperatures are maintained in the extraction region in volume-produced negative hydrogen ion sources. PMID:24593559

  10. Development of the negative ion beams relevant to ITER and JT-60SA at Japan Atomic Energy Agency

    NASA Astrophysics Data System (ADS)

    Hanada, M.; Kojima, A.; Tobari, H.; Nishikiori, R.; Hiratsuka, J.; Kashiwagi, M.; Umeda, N.; Yoshida, M.; Ichikawa, M.; Watanabe, K.; Yamano, Y.; Grisham, L. R.

    2016-02-01

    In order to realize negative ion sources and accelerators to be applicable to International Thermonuclear Experimental Reactor and JT-60 Super Advanced, a large cesium (Cs)-seeded negative ion source and a multi-aperture and multi-stage electric acceleration have been developed at Japan Atomic Energy Agency (JAEA). Long pulse production and acceleration of the negative ion beams have been independently carried out. The long pulse production of the high current beams has achieved 100 s at the beam current of 15 A by modifying the JT-60 negative ion source. The pulse duration time is increased three times longer than that before the modification. As for the acceleration, a pulse duration time has been also extended two orders of magnitudes from 0.4 s to 60 s. The developments of the negative ion source and acceleration at JAEA are well in progress towards the realization of the negative ion sources and accelerators for fusion applications.

  11. Development of the negative ion beams relevant to ITER and JT-60SA at Japan Atomic Energy Agency.

    PubMed

    Hanada, M; Kojima, A; Tobari, H; Nishikiori, R; Hiratsuka, J; Kashiwagi, M; Umeda, N; Yoshida, M; Ichikawa, M; Watanabe, K; Yamano, Y; Grisham, L R

    2016-02-01

    In order to realize negative ion sources and accelerators to be applicable to International Thermonuclear Experimental Reactor and JT-60 Super Advanced, a large cesium (Cs)-seeded negative ion source and a multi-aperture and multi-stage electric acceleration have been developed at Japan Atomic Energy Agency (JAEA). Long pulse production and acceleration of the negative ion beams have been independently carried out. The long pulse production of the high current beams has achieved 100 s at the beam current of 15 A by modifying the JT-60 negative ion source. The pulse duration time is increased three times longer than that before the modification. As for the acceleration, a pulse duration time has been also extended two orders of magnitudes from 0.4 s to 60 s. The developments of the negative ion source and acceleration at JAEA are well in progress towards the realization of the negative ion sources and accelerators for fusion applications. PMID:26932050

  12. Negative Mood Increases Selective Attention to Negatively Valenced Body Parts in Female Adolescents with Anorexia Nervosa

    PubMed Central

    Svaldi, Jennifer; Bender, Caroline; Caffier, Detlef; Ivanova, Viliana; Mies, Nina; Fleischhaker, Christian; Tuschen-Caffier, Brunna

    2016-01-01

    Objective Previous research has yielded evidence of increased attentional processing of negatively valenced body parts in women with anorexia nervosa (AN), especially for those with high depressive symptomatology. The present study extended previous research by implementing an experimental mood manipulation. Method In a within-subjects design, female adolescents with AN (n = 12) and an age matched female control group (CG; n = 12) were given a negative and a positive mood induction at a one-week interval. After each mood induction, participants underwent a 3-min mirror exposure, while their eye movements were recorded. Results After the positive mood induction, both AN and CG participants displayed longer and more frequent gazes towards their self-defined most ugly relative to their self-defined most beautiful body part. However, after the negative mood induction, only females with AN were characterized by increased attention to their most ugly compared to their most beautiful body part, while CG participants’ attention distribution was balanced. Furthermore, in the negative (but not in the positive) mood induction condition gaze frequency and duration towards the most ugly body part was significantly stronger in the AN group relative to the CG. Discussion The results emphasize the role of negative mood in the maintenance of pathological information processing of the self-body. This increased body-related negativity-bias during negative mood may lead to the persistence and aggravation of AN patients’ body image disturbance. PMID:27123587

  13. Vibrational States of Hydrogen Molecules in One Third LHD Negative Ion Source

    SciTech Connect

    Nishiura, M.; Tsumori, K.; Matsumoto, Y.; Wada, M.; Inoue, T.

    2011-09-26

    The effect of the cesium on hydrogen negative ions is discussed using the vacuum ultraviolet emissions (VUV) from vibrational states of hydrogen molecules. The VUV spectrum from 90 to 165 nm is related to the H{sup -} production from the dissociative attachment of electrons to hydrogen molecules. The VUV spectra in hydrogen plasmas are measured in the extraction region of a negative ion source for neutral beam injector. Under the pure hydrogen discharge, the cesium vapor is introduced into the ion source to enhance the hydrogen negative ion density. When the same arc power of {approx}99 kW is applied in both with and without cesium admixture cases, the ratio of the observed VUV spectrum without to with cesium is not changed clearly. Therefore the production process of H{sup -} related to the wall/electrode surface would be enhanced rather than the volume production process.

  14. Negative-stiffness-mechanism vibration isolation systems

    NASA Astrophysics Data System (ADS)

    Platus, David L.

    1992-02-01

    A new type of vibration isolation system offers significant improvement in performance compared with current state-of-the-art systems. The system uses negative-stiffness mechanisms to cancel the stiffness of a spring suspension. Reduction in stiffness magnifies the damping inherent in the system creating a practical means for achieving high hysteretic damping. The result is a simple, compact 6-DOF passive isolation system capable of system resonant frequencies below 0.2 Hz and first isolator resonances above 100 Hz. Resonant transmissibilities below 1.4 can be achieved with transmissibilities at the higher frequencies close to that of the ideal undamped system. The negative-stiffness mechanisms can cancel the stiffness of power cables, hoses or other lines connected to payloads. This paper develops the theory, describes typical configurations and summarizes test data with prototype systems.

  15. New types of negative ion sources

    SciTech Connect

    Borisko, V.N.; Lapshin, V.I.

    1995-12-31

    The plasma sources of negative ions which were elaborated in Kharkov State University are considered in this paper. These sources use the mechanism of dissociative stick of electrons with low energies to molecules of a working gas. The effective work of such sources needs a special system of low energy electrons formation. The effect of secondary electron emission used in negative ion sources is considered. The electrode material with a great coefficient of secondary electron emission allows one to obtain a few slow electrons per one bombarding electron. A plasma of Penning discharge is an emitter of initial elections. The electron electromagnetic trap in the secondary electron emission region allows one to enlarge volume of interaction of low energy electrons with the working gas molecules. The lifetime of slow electrons grows in this trap.

  16. Radiation quality of beams of negative pions

    SciTech Connect

    Dicello, J.F.; Brenner, D.J.

    1981-01-01

    As a negative pion stops in tissue, it attaches itself to an adjacent atom to form a mesonic atom. Subsequently, the wave function of the pion interacts with that of the nucleus and the pion is absorbed. Because the energy associated with the rest mass of the pion is greater than the separation energy of the nuclear particles, the nucleus disintegrates (pion star). In tissue, approximately 40 MeV goes into overcoming the binding energies; 20 MeV goes into kinetic energy of charged particles; 80 MeV goes into kinetic energy of neutrons. In cases where biological studies are performed with beams of negative pions, as much as 20% of the total absorbed dose in the treatment volume and about 50% of the high-LET dose (> 100 keV/..mu..m) can result from neutrons. The degree of biological response and the variation of that response throughout the treatment volume can be altered by the neutron dose.

  17. Mechanical metamaterials with negative compressibility transitions

    NASA Astrophysics Data System (ADS)

    Nicolaou, Zachary G.; Motter, Adilson E.

    2012-07-01

    When tensioned, ordinary materials expand along the direction of the applied force. Here, we explore network concepts to design metamaterials exhibiting negative compressibility transitions, during which a material undergoes contraction when tensioned (or expansion when pressured). Continuous contraction of a material in the same direction of an applied tension, and in response to this tension, is inherently unstable. The conceptually similar effect we demonstrate can be achieved, however, through destabilizations of (meta)stable equilibria of the constituents. These destabilizations give rise to a stress-induced solid-solid phase transition associated with a twisted hysteresis curve for the stress-strain relationship. The strain-driven counterpart of negative compressibility transitions is a force amplification phenomenon, where an increase in deformation induces a discontinuous increase in response force. We suggest that the proposed materials could be useful for the design of actuators, force amplifiers, micromechanical controls, and protective devices.

  18. Negative emotional stimuli enhance vestibular processing.

    PubMed

    Preuss, Nora; Ellis, Andrew W; Mast, Fred W

    2015-08-01

    Recent studies have shown that vestibular stimulation can influence affective processes. In the present study, we examined whether emotional information can also modulate vestibular perception. Participants performed a vestibular discrimination task on a motion platform while viewing emotional pictures. Six different picture categories were taken from the International Affective Picture System: mutilation, threat, snakes, neutral objects, sports, and erotic pictures. Using a Bayesian hierarchical approach, we were able to show that vestibular discrimination improved when participants viewed emotionally negative pictures (mutilation, threat, snake) when compared to neutral/positive objects. We conclude that some of the mechanisms involved in the processing of vestibular information are also sensitive to emotional content. Emotional information signals importance and mobilizes the body for action. In case of danger, a successful motor response requires precise vestibular processing. Therefore, negative emotional information improves processing of vestibular information. PMID:26098730

  19. Accounting for false negatives in hotspot detection

    SciTech Connect

    Sego, Landon H.; Wilson, John E.

    2007-08-28

    Hotspot sampling designs are used in environmental sampling to identify the location of one (or more) contiguous regions of elevated contamination. These regions are known as hotspots. The problem of how to calculate the probability of detecting an elliptical hotspot using a rectangular or triangular grid of sampling points was addressed by Singer and Wickman in 1969. This approach presumed that any sample which coincided with a hotspot would detect the hotspot without error. However, for many sampling methodologies, there is a chance that the hotspot will not be detected even though it has been sampled directly--a false negative. We present a mathematical solution and a numerical algorithm which account for false negatives when calculating the probability of detecting hotspots that are circular in shape.

  20. Mechanical metamaterials with negative compressibility transitions.

    PubMed

    Nicolaou, Zachary G; Motter, Adilson E

    2012-07-01

    When tensioned, ordinary materials expand along the direction of the applied force. Here, we explore network concepts to design metamaterials exhibiting negative compressibility transitions, during which a material undergoes contraction when tensioned (or expansion when pressured). Continuous contraction of a material in the same direction of an applied tension, and in response to this tension, is inherently unstable. The conceptually similar effect we demonstrate can be achieved, however, through destabilizations of (meta)stable equilibria of the constituents. These destabilizations give rise to a stress-induced solid-solid phase transition associated with a twisted hysteresis curve for the stress-strain relationship. The strain-driven counterpart of negative compressibility transitions is a force amplification phenomenon, where an increase in deformation induces a discontinuous increase in response force. We suggest that the proposed materials could be useful for the design of actuators, force amplifiers, micromechanical controls, and protective devices. PMID:22609557

  1. Nociception, pain, negative moods and behavior selection

    PubMed Central

    Baliki, Marwan N.; Apkarian, A. Vania

    2015-01-01

    Recent neuroimaging studies suggest that the brain adapts with pain, as well as imparts risk for developing chronic pain. Within this context we revisit the concepts for nociception, acute and chronic pain, and negative moods relative to behavior selection. We redefine nociception as the mechanism protecting the organism from injury; while acute pain as failure of avoidant behavior; and a mesolimbic threshold process that gates the transformation of nociceptive activity to conscious pain. Adaptations in this threshold process are envisioned to be critical for development of chronic pain. We deconstruct chronic pain into four distinct phases, each with specific mechanisms; and outline current state of knowledge regarding these mechanisms: The limbic brain imparting risk, while mesolimbic learning processes reorganizing the neocortex into a chronic pain state. Moreover, pain and negative moods are envisioned as a continuum of aversive behavioral learning, which enhance survival by protecting against threats. PMID:26247858

  2. Mechanical Metamaterials with Negative Compressibility Transitions

    NASA Astrophysics Data System (ADS)

    Motter, Adilson

    2015-03-01

    When tensioned, ordinary materials expand along the direction of the applied force. In this presentation, I will explore network concepts to design metamaterials exhibiting negative compressibility transitions, during which the material undergoes contraction when tensioned (or expansion when pressured). Such transitions, which are forbidden in thermodynamic equilibrium, are possible during the decay of metastable, super-strained states. I will introduce a statistical physics theory for negative compressibility transitions, derive a first-principles model to predict these transitions, and present a validation of the model using molecular dynamics simulations. Aside from its immediate mechanical implications, our theory points to a wealth of analogous inverted responses, such as inverted susceptibility or heat-capacity transitions, allowed when considering realistic scales. This research was done in collaboration with Zachary Nicolaou, and was supported by the National Science Foundation and the Alfred P. Sloan Foundation.

  3. Proactive and retroactive effects of negative suggestion.

    PubMed

    Brown, Alan S; Brown, Christine M; Mosbacher, Joy L; Dryden, W Erich

    2006-11-01

    The negative effects of false information presented either prior to (proactive interference; PI) or following (retroactive interference; RI) true information was examined with word definitions (Experiment 1) and trivia facts (Experiment 2). Participants were explicitly aware of which information was true and false when shown, and true-false discrimination was evaluated via multiple-choice tests. Negative suggestion, defined as poorer performance on interference items than noninterference (control) items, consistently occurred when the wrong information followed the correct information (RI) but not when it preceded the correct information (PI). These effects did not change as a function of retention interval (immediate, 1 week, or 3 weeks) or number of incorrect alternatives (1 or 3). Implications of this outcome for experiencing incorrect information in both academic and nonacademic situations are considered. PMID:17087580

  4. Structures with negative index of refraction

    DOEpatents

    Soukoulis, Costas M.; Zhou, Jiangfeng; Koschny, Thomas; Zhang, Lei; Tuttle, Gary

    2011-11-08

    The invention provides simplified negative index materials (NIMs) using wire-pair structures, 4-gap single ring split-ring resonator (SRR), fishnet structures and overleaf capacitor SRR. In the wire-pair arrangement, a pair of short parallel wires and continuous wires are used. In the 4-gap single-ring SRR, the SRRs are centered on the faces of a cubic unit cell combined with a continuous wire type resonator. Combining both elements creates a frequency band where the metamaterial is transparent with simultaneously negative .di-elect cons. and .mu.. In the fishnet structure, a metallic mesh on both sides of the dielectric spacer is used. The overleaf capacitor SRR changes the gap capacities to small plate capacitors by making the sections of the SRR ring overlap at the gaps separated by a thin dielectric film. This technique is applicable to conventional SRR gaps but it best deploys for the 4-gap single-ring structures.

  5. Ground state of the hydrogen negative ion

    NASA Astrophysics Data System (ADS)

    Obreshkov, Boyan

    2009-03-01

    Based on recently developed variational many-body Schr"odinger equation for electrons with Coulomb interactions [1], we provide first numerical results for the ground state electron structure of the hydrogen negative ion. It is shown that Fermi-Teller promotion effect together with non-adiabatic screening effects due to the Pauli's exclusion principle are responsible for the weak binding of the anion. The calculated ionization potential J=-1/2 - 2 λ+ <1/r12> of the hydrogen negative ion is compared with the experiment, where λ is the mean binding energy per one electron in the ground state.[0pt] [1] B. D. Obreshkov , Phys. Rev. A 78, 032503 (2008).

  6. Generation of intense negative ion beams

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Orient, Otto J. (Inventor); Aladzhadzhyan, Samuel H. (Inventor)

    1987-01-01

    An electron gun is used with a mirror electrostatic field to produce zero or near zero velocity electrons by forming a turning point in their trajectories. A gas capable of attaching zero or near zero velocity is introduced at this turning point, and negative ions are produced by the attachment or dissociative attachment process. Operation may be continuous or pulsed. Ions thus formed are extracted by a simple lens system and suitable biasing of grids.

  7. Negative Electrodes for Li-Ion Batteries

    SciTech Connect

    Kinoshita, Kim; Zaghib, Karim

    2001-10-01

    Graphitized carbons have played a key role in the successful commercialization of Li-ion batteries. The physicochemical properties of carbon cover a wide range; therefore identifying the optimum active electrode material can be time consuming. The significant physical properties of negative electrodes for Li-ion batteries are summarized, and the relationship of these properties to their electrochemical performance in nonaqueous electrolytes, are discussed in this paper.

  8. Thyroid antibody-negative euthyroid Graves’ ophthalmopathy

    PubMed Central

    Khan, Ishrat; Taylor, Peter; Das, Gautam; Okosieme, Onyebuchi E

    2016-01-01

    Summary TSH receptor antibodies (TRAbs) are the pathological hallmark of Graves’ disease, present in nearly all patients with the disease. Euthyroid Graves’ ophthalmopathy (EGO) is a well-recognized clinical entity, but its occurrence in patients with negative TRAbs is a potential source of diagnostic confusion. A 66-year-old female presented to our endocrinology clinic with right eye pain and diplopia in the absence of thyroid dysfunction. TRAbs were negative, as measured with a highly sensitive third-generation thyrotropin-binding inhibitory immunoglobulin (TBII) ELISA assay. CT and MRI scans of the orbit showed asymmetrical thickening of the inferior rectus muscles but no other inflammatory or malignant orbital pathology. Graves’ ophthalmopathy (GO) was diagnosed on the basis of the clinical and radiological features, and she underwent surgical recession of the inferior rectus muscle with complete resolution of the diplopia and orbital pain. She remained euthyroid over the course of follow-up but ultimately developed overt clinical and biochemical hyperthyroidism, 24 months after the initial presentation. By this time, she had developed positive TRAb as well as thyroid peroxidase antibodies. She responded to treatment with thionamides and remains euthyroid. This case highlights the potential for negative thyroid-specific autoantibodies in the presentation of EGO and underscores the variable temporal relationship between the clinical expression of thyroid dysfunction and orbital disease in the natural evolution of Graves’ disease. Learning points Euthyroid Graves’ ophthalmopathy can present initially with negative thyroid-specific autoantibodies. Patients with suggestive symptoms of ophthalmopathy should be carefully evaluated for GO with imaging studies even when thyroid function and autoantibodies are normal. Patients with EGO can develop thyroid dysfunction within 4 years of follow-up underpinning the need for long-term follow-up and continued

  9. Hydrophobic surfactant proteins strongly induce negative curvature.

    PubMed

    Chavarha, Mariya; Loney, Ryan W; Rananavare, Shankar B; Hall, Stephen B

    2015-07-01

    The hydrophobic surfactant proteins SP-B and SP-C greatly accelerate the adsorption of vesicles containing the surfactant lipids to form a film that lowers the surface tension of the air/water interface in the lungs. Pulmonary surfactant enters the interface by a process analogous to the fusion of two vesicles. As with fusion, several factors affect adsorption according to how they alter the curvature of lipid leaflets, suggesting that adsorption proceeds via a rate-limiting structure with negative curvature, in which the hydrophilic face of the phospholipid leaflets is concave. In the studies reported here, we tested whether the surfactant proteins might promote adsorption by inducing lipids to adopt a more negative curvature, closer to the configuration of the hypothetical intermediate. Our experiments used x-ray diffraction to determine how the proteins in their physiological ratio affect the radius of cylindrical monolayers in the negatively curved, inverse hexagonal phase. With binary mixtures of dioleoylphosphatidylethanolamine (DOPE) and dioleoylphosphatidylcholine (DOPC), the proteins produced a dose-related effect on curvature that depended on the phospholipid composition. With DOPE alone, the proteins produced no change. With an increasing mol fraction of DOPC, the response to the proteins increased, reaching a maximum 50% reduction in cylindrical radius at 5% (w/w) protein. This change represented a doubling of curvature at the outer cylindrical surface. The change in spontaneous curvature, defined at approximately the level of the glycerol group, would be greater. Analysis of the results in terms of a Langmuir model for binding to a surface suggests that the effect of the lipids is consistent with a change in the maximum binding capacity. Our findings show that surfactant proteins can promote negative curvature, and support the possibility that they facilitate adsorption by that mechanism. PMID:26153706

  10. Lower body graduated negative pressure system

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The first task concerning the Lower Body Negative Pressure Suit was to determine the best type construction for a leg section with these goals in mind: good mobility, minimum amount of bulk, ease of storage, lightweight, rigid enough to withstand atmospheric pressure, and minimum amount of preparation before donning and donning time. After a study of three systems, wire hoops (rings) separated on inch apart in an airtight material furnished by NASA were chosen.

  11. Veillonella, Firmicutes: Microbes disguised as Gram negatives

    PubMed Central

    Vesth, Tammi; Ozen, Aslı; Andersen, Sandra C.; Kaas, Rolf Sommer; Lukjancenko, Oksana; Bohlin, Jon; Nookaew, Intawat; Wassenaar, Trudy M.; Ussery, David W.

    2013-01-01

    The Firmicutes represent a major component of the intestinal microflora. The intestinal Firmicutes are a large, diverse group of organisms, many of which are poorly characterized due to their anaerobic growth requirements. Although most Firmicutes are Gram positive, members of the class Negativicutes, including the genus Veillonella, stain Gram negative. Veillonella are among the most abundant organisms of the oral and intestinal microflora of animals and humans, in spite of being strict anaerobes. In this work, the genomes of 24 Negativicutes, including eight Veillonella spp., are compared to 20 other Firmicutes genomes; a further 101 prokaryotic genomes were included, covering 26 phyla. Thus a total of 145 prokaryotic genomes were analyzed by various methods to investigate the apparent conflict of the Veillonella Gram stain and their taxonomic position within the Firmicutes. Comparison of the genome sequences confirms that the Negativicutes are distantly related to Clostridium spp., based on 16S rRNA, complete genomic DNA sequences, and a consensus tree based on conserved proteins. The genus Veillonella is relatively homogeneous: inter-genus pair-wise comparison identifies at least 1,350 shared proteins, although less than half of these are found in any given Clostridium genome. Only 27 proteins are found conserved in all analyzed prokaryote genomes. Veillonella has distinct metabolic properties, and significant similarities to genomes of Proteobacteria are not detected, with the exception of a shared LPS biosynthesis pathway. The clade within the class Negativicutes to which the genus Veillonella belongs exhibits unique properties, most of which are in common with Gram-positives and some with Gram negatives. They are only distantly related to Clostridia, but are even less closely related to Gram-negative species. Though the Negativicutes stain Gram-negative and possess two membranes, the genome and proteome analysis presented here confirm their place within the

  12. SIGIRR, a negative regulator of colon tumorigenesis

    PubMed Central

    Zhao, Junjie; Zepp, Jarod; Bulek, Katarzyna; Li, Xiaoxia

    2012-01-01

    Inappropriate activation of the Toll-IL-1R (TL-IL-1) signaling by commensal bacteria contributes to the pathogenesis of inflammatory bowel diseases and colitis-associated cancer. Recent studies have identified SIGIRR as a negative regulator of TL-IL-1 signaling. It dampens intestinal inflammation and tumorigenesis in the colon. In this review, we will discuss the role of SIGIRR in different cell types and the mechanisms underlying its tumor suppressor function. PMID:22529873

  13. A computational approach to negative priming

    NASA Astrophysics Data System (ADS)

    Schrobsdorff, H.; Ihrke, M.; Kabisch, B.; Behrendt, J.; Hasselhorn, M.; Herrmann, J. Michael

    2007-09-01

    Priming is characterized by a sensitivity of reaction times to the sequence of stimuli in psychophysical experiments. The reduction of the reaction time observed in positive priming is well-known and experimentally understood (Scarborough et al., J. Exp. Psycholol: Hum. Percept. Perform., 3, pp. 1-17, 1977). Negative priming—the opposite effect—is experimentally less tangible (Fox, Psychonom. Bull. Rev., 2, pp. 145-173, 1995). The dependence on subtle parameter changes (such as response-stimulus interval) usually varies. The sensitivity of the negative priming effect bears great potential for applications in research in fields such as memory, selective attention, and ageing effects. We develop and analyse a computational realization, CISAM, of a recent psychological model for action decision making, the ISAM (Kabisch, PhD thesis, Friedrich-Schiller-Universitat, 2003), which is sensitive to priming conditions. With the dynamical systems approach of the CISAM, we show that a single adaptive threshold mechanism is sufficient to explain both positive and negative priming effects. This is achieved by comparing results obtained by the computational modelling with experimental data from our laboratory. The implementation provides a rich base from which testable predictions can be derived, e.g. with respect to hitherto untested stimulus combinations (e.g. single-object trials).

  14. Lesion-negative anterior cingulate epilepsy.

    PubMed

    Lacuey, Nuria; Davila, Javier Chapa; Zonjy, Bilal; Amina, Shahram; Couce, Marta; Turnbull, John; Miller, Jonathan; Lüders, Hans; Lhatoo, Samden D

    2015-06-01

    MRI-negative anterior cingulate epilepsy is a rare entity. Herein, we describe a case of MRI and functional imaging-negative intractable frontal lobe epilepsy in which, initially, secondary bilateral synchrony of surface and intracranial EEG and non-lateralizing semiology rendered identification of the epileptogenic zone difficult. A staged bilateral stereotactic EEG exploration revealed a very focal, putative ictal onset zone in the right anterior cingulate gyrus, as evidenced by interictal and ictal high-frequency oscillations (at 250Hz) and induction of seizures from the same electrode contacts by 50-Hz low-intensity cortical stimulation. This was subsequently confirmed by ILAE class 1 outcome following resection of the ictal onset and irritative zones. Histopathological examination revealed focal cortical dysplasia type 1b (ILAE Commission, 2011) as the cause of epilepsy. The importance of anatomo-electro-clinical correlation is illustrated in this case in which semiological and electrophysiological features pointed to the anatomical localization of a challenging, MRI-negative epilepsy. PMID:26056053

  15. Negative-tone 193-nm resists

    NASA Astrophysics Data System (ADS)

    Cho, Sungseo; Vander Heyden, Anthony; Byers, Jeff D.; Willson, C. Grant

    2000-06-01

    A great deal of progress has been made in the design of single layer positive tone resists for 193 nm lithography. Commercial samples of such materials are now available from many vendors. The patterning of certain levels of devices profits from the use of negative tone resists. There have been several reports of work directed toward the design of negative tones resists for 193 nm exposure but, none have performed as well as the positive tone systems. Polymers with alicyclic structures in the backbone have emerged as excellent platforms from which to design positive tone resists for 193 nm exposure. We now report the adaptation of this class of polymers to the design of high performance negative tone 193 nm resists. New systems have been prepared that are based on a polarity switch mechanism for modulation of the dissolution rate. The systems are based on a polar, alicyclic polymer backbone that includes a monomer bearing a glycol pendant group that undergoes the acid catalyzed pinacol rearrangement upon exposure and bake to produce the corresponding less polar ketone. This monomer was copolymerized with maleic anhydride and a norbornene bearing a bis-trifluoromethylcarbinol. The rearrangement of the copolymer was monitored by FT-IR as a function of temperature. The synthesis of the norbornene monomers will be presented together with characterization of copolymers of these monomers with maleic anhydride. The lithographic performance of the new resist system will also be presented.

  16. Negative Halogen Ions for Fusion Applications

    SciTech Connect

    Grisham, L.R.; Kwan, J.W.; Hahto, S.K.; Hahto, S.T.; Leung, K.N.; Westenskow, G.

    2006-01-01

    Over the past quarter century, advances in hydrogen negative ion sources have extended the usable range of hydrogen isotope neutral beams to energies suitable for large magnetically confined fusion devices. Recently, drawing upon this experience, negative halogen ions have been proposed as an alternative to positive ions for heavy ion fusion drivers in inertial confinement fusion, because electron accumulation would be prevented in negative ion beams, and if desired, the beams could be photo-detached to neutrals. This paper reports the results of an experiment comparing the current density and beam emittance of Cl+ and Cl- extracted from substantially ion-ion plasmas with that of Ar+ extracted from an ordinary electron-ion plasma, all using the same source, extractor, and emittance scanner. At similar discharge conditions, the Cl- current was typically 85 – 90% of the positive chlorine current, with an e-/ Cl- ratio as low as seven without grid magnets. The Cl- was as much as 76% of the Ar+ current from a discharge with the same RF drive. The minimum normalized beam emittance and inferred ion temperatures of Cl+, Cl-, and Ar+ were all similar, so the current density and optical quality of Cl- appear as suitable for heavy ion fusion driver applications as a positive noble gas ion of similar mass. Since F, I, and Br should all behave similarly in an ion source, they should also be suitable as driver beams.

  17. Negative excess noise in gated quantum wires

    SciTech Connect

    Dolcini, F.; Trauzettel, B.; Safi, I.; Grabert, H.

    2009-04-23

    The electrical current noise of a quantum wire is expected to increase with increasing applied voltage. We show that this intuition can be wrong. Specifically, we consider a single channel quantum wire with impurities and with a capacitive coupling to a metallic gate, and find that its excess noise, defined as the change in the noise caused by the finite voltage, can be negative at zero temperature. This feature is present both for large (c>>c{sub q}) and small (c<>c{sub q}, negativity of the excess noise can occur at finite frequency when the transmission coefficients are energy dependent, i.e. in the presence of Fabry-Perot resonances or band curvature. In the opposite regime c < or approx. c{sub q}, a non trivial voltage dependence of the noise arises even for energy independent transmission coefficients: at zero frequency the noise decreases with voltage as a power law when cnegative excess noise are present due to Andreev-type resonances.

  18. Negative ion states of sulfur hexafluoride

    SciTech Connect

    Chen, E.C.M.; Shuie, L.; Desai D'sa, E.; Batten, C.F.; Wentworth, W.E.

    1988-04-15

    The reaction of SF/sub 6/ with thermal electrons has been studied in a Ni-63 atmospheric pressure ionization source for a quadrupole mass spectrometer (API/MS). The major ions that are observed are the parent negative ion (SF/sup -//sub 6/) and the parent minus a fluorine atom (SF/sup -//sub 5/). The ratio of (SF/sup -//sub 5/)/(SF/sup -//sub 6/) is highly temperature dependent above 500 K. The dissociation energy of the ground state negative ion into SF/sup -//sub 5/ and F has been determined to be 1.35 +- 0.1 eV. This gives values of 3.8 +- 0.15 eV for the electron affinity of SF/sub 5/ and 1.15 +- 0.15 eV for the electron affinity of SF/sub 6/. The negative ion states of sulfur hexafluoride have been described by ''pseudo-two-dimensional'' Morse potentials calculated using experimental data.

  19. Negative Stress Margins - Are They Real?

    NASA Technical Reports Server (NTRS)

    Raju, Ivatury S.; Lee, Darlene S.; Mohaghegh, Michael

    2011-01-01

    Advances in modeling and simulation, new finite element software, modeling engines and powerful computers are providing opportunities to interrogate designs in a very different manner and in a more detailed approach than ever before. Margins of safety are also often evaluated using local stresses for various design concepts and design parameters quickly once analysis models are defined and developed. This paper suggests that not all the negative margins of safety evaluated are real. The structural areas where negative margins are frequently encountered are often near stress concentrations, point loads and load discontinuities, near locations of stress singularities, in areas having large gradients but with insufficient mesh density, in areas with modeling issues and modeling errors, and in areas with connections and interfaces, in two-dimensional (2D) and three-dimensional (3D) transitions, bolts and bolt modeling, and boundary conditions. Now, more than ever, structural analysts need to examine and interrogate their analysis results and perform basic sanity checks to determine if these negative margins are real.

  20. IMMUNOHISTOCHEMICAL DIFFERENTIATION OF TRIPLE NEGATIVE BREAST CANCER.

    PubMed

    Lesar, Miroslav; Stanec, Mladen; Lesar, Nikola; Vrdoljak, Danko Velimir; Zore, Zvonimir; Banović, Marija; Brozović, Gordana

    2016-03-01

    Based on immunohistochemical staining for the basal markers cytokeratin 5/6 (CK 5/6), cytokeratin 14 (CK 14) and P-cadherin, triple negative tumors (TNT) are divided into two groups: 1) basal-like (BL) positive for one or all three markers; and 2) non basal-like (NBL) negative for all three markers. Even though the different origin of the cells of these two types of tumors implies different biological properties, they had been treated as one entity until recently. This paper analyzes TNT collected from 150 patients and distributed into two groups according to the results of immunohistochemical analysis, i.e. BL 116 (77.3%) and NBL 34 (22.67%). In this study, CK 5/6, CK 14 and P-cadherin were used as markers for identifying BL tumors. The immunohistochemical reaction was positive for CK 5/6 in 37%, for CK 14 in 50.86% and for P-cadherin in 68.34% of cases. The subclassification of triple negative breast cancer using the basal markers CK 5/6, CK 14 and P-cadherin has enabled identification of BL and NBL breast cancers in a proportion that is in line with the only accurate analysis of TNT gene expression. Using the mentioned combination of markers in daily practice is easy to perform and economically affordable. PMID:27333711

  1. Simulation Based on Ion Propulsion Rocket System with Using Negative ion - Negative Ion Pair Techniques

    NASA Astrophysics Data System (ADS)

    Sathiyavel, C.

    2016-07-01

    Ion propulsion rocket system is expected to become popular with the development of ion-ion pair techniques because of their stimulated of low propellant, Design of Thrust range is 1N with low electric power and high efficiency. A Negative ion-Negative ion pair of ion propulsion rocket system is proposed in this work .Negative Ion Based Rocket system consists of three parts 1.ionization chamber 2. Repulsion force and ion accelerator 3. Exhaust of Nozzle. The Negative ions from electro negatively gas are produced by attachment of the gas ,such as chlorine with electron emitted from a Electron gun ionization chamber. The formulate of large stable negative ion is achievable in chlorine gas with respect to electron affinity (∆E). The electron affinity is a measure of the energy change when an electron is added to a neutral atom to form a negative ion. When a neutral chlorine atom in the gaseous form picks up an electron to form a Cl- ion, it releases energy of 349 kJ/mol or 3.6 ev/atom. It is said to have an electron affinity of -349 kJ/mol ,the negative sign indicating that energy is released during this process .The mechanisms of attachment involve the formation of intermediate states. In that reason for , the highly repulsive force created between the same negative ions. The distance between same negative ions is important for the evaluate of the rocket thrust and is also determined by the exhaust velocity of the propellant. The mass flow rate of propellant is achieved by the ratio of total mass of the propellant (Kg) needed for operation to time period(s). Accelerate the Negative ions to a high velocity in the thrust vector direction with a significantly intense Magnetic field and the exhaust of negative ions through Nozzle. The simulation of the ion propulsion system has been carried out by MATLAB. By comparing the simulation results with the theoretical and previous results, we have found that the proposed method is achieved of thrust value with estimated

  2. 9 CFR 85.8 - Interstate movement of swine from a qualified negative gene-altered vaccinated herd.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Interstate movement of swine from a qualified negative gene-altered vaccinated herd. 85.8 Section 85.8 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS PSEUDORABIES § 85.8 Interstate movement of swine from a...

  3. 9 CFR 85.8 - Interstate movement of swine from a qualified negative gene-altered vaccinated herd.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Interstate movement of swine from a qualified negative gene-altered vaccinated herd. 85.8 Section 85.8 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS PSEUDORABIES § 85.8 Interstate movement of swine from a...

  4. Extended negative dietary cation-anion difference feeding does not negatively affect postpartum performance of multiparous dairy cows.

    PubMed

    Weich, W; Block, E; Litherland, N B

    2013-09-01

    Low postpartum blood calcium remains one of the largest constraints to postpartum feed intake, milk yield, and energy balance in transitioning dairy cows. Supplemental dietary anions decrease the dietary cation-anion difference (DCAD) and reduce the risk for postpartum hypocalcemia. Prepartum management strategies aiming to minimize social stress and diet changes have resulted in a need to explore the effects of extended exposure to a negative DCAD (>21 d) diet. Holstein and Holstein-cross dairy cows (n=60) were assigned to 1 of 3 treatments 42 d before expected calving to evaluate effects of supplying anions for 21 or 42 d during the dry period on energy status, postpartum production, and Ca homeostasis. Treatments included (1) a control diet (CON; DCAD=12 mEq/100 g of DM), (2) a 21-d negative DCAD diet (21-ND; DCAD=12 and -16 mEq/100 g of DM), and (3) a 42-d negative DCAD diet (42-ND; DCAD=-16 mEq/100 g of DM). Cows fed CON were fed positive DCAD prepartum for 42 d. Cows fed 21-ND received the positive DCAD (12 mEq/100 g of DM) diet for the first 21 d of the dry period and the anionic diet (-16 mEq/100 g of DM) from d 22 until calving. Cows fed 42-ND received the anionic diet for the entire dry period. Control and anionic diets were formulated by using 2 isonitrogenous protein mixes: (1) 97.5% soybean meal and (2) 52.8% BioChlor (Church & Dwight Co. Inc.), 45.8% soybean meal. Supplementing anions induced a mild metabolic acidosis, reducing urine pH for 21-ND and 42-ND compared with CON. Prepartum DMI was not different among treatments. Postpartum DMI was higher for 21-ND compared with CON (20.8 vs. 18.1±1.1 kg/d), and 42-ND had similar DMI compared with 21-ND. During the first 56 d of lactation 21-ND had greater average milk production compared with CON (44.8 vs. 39.2±2.1 kg/d). Average milk production by 42-ND was similar to 21-ND. Postpartum total blood Ca concentration was greater for 42-ND. Cows fed anionic diets prepartum tended to have lower lipid

  5. A bacterial gene codA encoding cytosine deaminase is an effective conditional negative selectable marker in Glycine max

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background Conditional negative selection is a powerful technique whereby the absence of a gene product allows survival in otherwise lethal conditions. In plants, the Escherichia coli gene codA has been employed as a negative selection marker. CodA is a conditionally lethal dominant gene encoding cy...

  6. 9 CFR 85.6 - Interstate movement of pseudorabies vaccinate swine, except swine from qualified negative gene...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... vaccinate swine, except swine from qualified negative gene-altered vaccinated herds, not known to be... POULTRY) AND ANIMAL PRODUCTS PSEUDORABIES § 85.6 Interstate movement of pseudorabies vaccinate swine, except swine from qualified negative gene-altered vaccinated herds, not known to be infected with...

  7. 9 CFR 85.6 - Interstate movement of pseudorabies vaccinate swine, except swine from qualified negative gene...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... vaccinate swine, except swine from qualified negative gene-altered vaccinated herds, not known to be... POULTRY) AND ANIMAL PRODUCTS PSEUDORABIES § 85.6 Interstate movement of pseudorabies vaccinate swine, except swine from qualified negative gene-altered vaccinated herds, not known to be infected with...

  8. 9 CFR 85.6 - Interstate movement of pseudorabies vaccinate swine, except swine from qualified negative gene...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... vaccinate swine, except swine from qualified negative gene-altered vaccinated herds, not known to be... POULTRY) AND ANIMAL PRODUCTS PSEUDORABIES § 85.6 Interstate movement of pseudorabies vaccinate swine, except swine from qualified negative gene-altered vaccinated herds, not known to be infected with...

  9. Plasma Structure in the Extraction Region of a Hybrid Negative Ion Source

    SciTech Connect

    Taccogna, F.; Longo, S.; Capitelli, M.

    2009-03-12

    Production, destruction and transport of negative ions in the extraction region of a hybrid negative ion source are investigated with a one-dimensional Particle-in-Cell electrostatic code. The influence of the plasma grid bias and of the magnetic filter on the plasma parameter profiles is taken into account. In particular, a transition from classical to complete reverse sheath is observed using a positively biased plasma grid, while the effect of the magnetic filter is relatively small proofing that H{sup -} production is dominated by surface neutral conversion.

  10. EDITORIAL: Negative ion based neutral beam injection

    NASA Astrophysics Data System (ADS)

    Hemsworth, R. S.

    2006-06-01

    It is widely recognized that neutral beam injection (NBI), i.e. the injection of high energy, high power, beams of H or D atoms, is a flexible and reliable system that has been the main heating system on a large variety of fusion devices, and NBI has been chosen as one of the three heating schemes of the International Tokomak Reactor (ITER). To date, all the NBI systems but two have been based on the neutralization (in a simple gas target) of positive hydrogen or deuterium ions accelerated to <100 keV/nucleon. Above that energy the neutralization of positive ions falls to unacceptably low values, and higher energy neutral beams have to be created by the neutralization of accelerated negative ions (in a simple gas target), as this remains high (approx60%) up to >1 MeV/nucleon. Unfortunately H- and D- are difficult to create, and the very characteristic that makes them attractive, the ease with which the electron is detached from the ion, means that it is difficult to create high concentrations or fluxes of them, and it is difficult to avoid substantial, collisional, losses in the extraction and acceleration processes. However, there has been impressive progress in negative ion sources and accelerators over the past decade, as demonstrated by the two pioneering, operational, multi-megawatt, negative ion based, NBI systems at LHD (180 keV, H0) and JT-60U (500 keV, D0), both in Japan. Nevertheless, the system proposed for ITER represents a substantial technological challenge as an increase is required in beam energy, to 1 MeV, D0, accelerated ion (D-) current, to 40 A, accelerated current density, 200 A m-2 of D-, and pulse length, to 1 h. At the Fourth IAEA Technical Meeting on Negative Ion Based Neutral Beam Injectors, hosted by the Consorzio RFX, Padova, Italy, 9-11 May 2005, the status of the R&D aimed at the realization of the injectors for ITER was presented. Because of the importance of this development to the success of the ITER project, participants at that

  11. Negative pressure therapy: theory and practice.

    PubMed

    Schintler, M V

    2012-02-01

    Negative pressure (wound) therapy, synonymous with topical negative pressure or vacuum therapy mainly cited as branded VAC® (vacuum-assisted closure) therapy, is a mode of therapy used to encourage wound healing. It is used both as primary treatment of chronic and complex wounds and as an adjunct for temporary closure and wound bed preparation preceding surgical procedures such as skin grafts and flap surgery. The device has come into wide and successful use, although the physiological basis of its effect is not yet fully understood, and with a delay, increasingly evidence-based data become available. A meta-analysis was made of peer-reviewed publications (PubMed-Medline) chosen on the basis of inclusion of the terms randomized clinical trial, vacuum-assisted closure, and topical negative pressure. Scientific data were evaluated from experimental animal studies, randomized clinical trials, observations of clinical applications, and case reports on all known effects of VAC therapy. Systematic analysis of the data shows efficacy concerning induction of wound healing mechanisms, especially in the early stage. Increased perfusion can be considered proven. Data analysis shows positive efficacy for treatment of infection. Although this therapy appears effective and its superiority to conventional techniques has been demonstrated, there are still some critical votes concerning efficacy. Because its mechanisms of action remain unclear, and because there is still some gap between evidence-based data and the excellent clinical results, further prospective, randomized, blinded studies are needed. Even so, we conclude that vacuum therapy, used when indicated and especially by experienced surgeons, is an excellent tool to support wound healing. PMID:22271727

  12. [Negative symptoms in schizophrenia and substance-related disorders].

    PubMed

    Simon, N; Belzeaux, R; Adida, M; Azorin, J-M

    2015-12-01

    Dual diagnosis of schizophrenia and substance-related disorders is common in psychiatric practice. Epidemiologic studies and report have established that the risk of a substance-related disorder was 4 to 5 times higher in a population of psychiatric patients than in the general population. However, little is known on the reason of this relationship and the treatments required. It's well known that a family history of psychosis is a risk factor of schizophrenia. Similarly a family history of substance use disorders increases the risk of using substances. Because the two disorders often occurred together, it could be hypothesized that a genetic risk factor is common. However, recent studies did not confirm this hypothesis and it seems that their genetic risks factor would be unrelated. Evidence now exists describing the different profiles of patients whether they used substance or not. Concerning negative symptoms clinical studies and meta-analyses have described fewer symptoms in schizophrenia patients with a substance use disorder. Among the different explanations that have been addressed, it seems that a lower capability of obtaining the substance could partly explain this relationship. Perhaps because patients with social withdrawal have more difficulties to find and spend the time required to obtain abused substances. At the opposite some products such as cocaine may relieve some symptoms especially anhedonia and alogia. However the link between substance-related disorders and negative symptoms is weak and decreases in more recent studies, probably because negative symptoms as well as addiction disorders are better characterized. Considering that treating psychiatric symptoms may not always lead to a decrease in the substance-related disorders but that patients who give up substances improve their psychotic symptoms, a therapeutic strategy should be planned for these dual disorders patients combining psychiatry and addiction interventions. PMID:26776388

  13. Negative Gaussian curvature from induced metric changes.

    PubMed

    Modes, Carl D; Warner, Mark

    2015-07-01

    We revisit the light or heat-induced changes in topography of initially flat sheets of a solid that elongate or contract along patterned in-plane director fields. For radial or azimuthal directors, negative Gaussian curvature is generated-so-called "anticones." We show that azimuthal material displacements are required for the distorted state to be stretch free and bend minimizing. The resultant shapes are smooth and asterlike and can become reentrant in the azimuthal coordinate for large deformations. We show that care is needed when considering elastomers rather than glasses, although the former offer huge deformations. PMID:26274106

  14. Growing Networks with Positive and Negative Links

    NASA Astrophysics Data System (ADS)

    Dech, Corynne; Antwi, Shadrack; Shaw, Leah

    Scale-free networks grown via preferential attachment have been used to model real-world networks such as the Internet, citation networks, and social networks. Here we investigate signed scale-free networks where an edge represents a positive or negative connection. We present analytic results and simulation for a growing signed network model. We compare the signed network to an unsigned scale-free network. We discuss several options for preferential attachment in a signed network that could be further adapted to model the accumulation of links over time in real-world signed networks.

  15. Negative Selection Algorithm for Aircraft Fault Detection

    NASA Technical Reports Server (NTRS)

    Dasgupta, D.; KrishnaKumar, K.; Wong, D.; Berry, M.

    2004-01-01

    We investigated a real-valued Negative Selection Algorithm (NSA) for fault detection in man-in-the-loop aircraft operation. The detection algorithm uses body-axes angular rate sensory data exhibiting the normal flight behavior patterns, to generate probabilistically a set of fault detectors that can detect any abnormalities (including faults and damages) in the behavior pattern of the aircraft flight. We performed experiments with datasets (collected under normal and various simulated failure conditions) using the NASA Ames man-in-the-loop high-fidelity C-17 flight simulator. The paper provides results of experiments with different datasets representing various failure conditions.

  16. Visual mismatch negativity: a predictive coding view.

    PubMed

    Stefanics, Gábor; Kremláček, Jan; Czigler, István

    2014-01-01

    An increasing number of studies investigate the visual mismatch negativity (vMMN) or use the vMMN as a tool to probe various aspects of human cognition. This paper reviews the theoretical underpinnings of vMMN in the light of methodological considerations and provides recommendations for measuring and interpreting the vMMN. The following key issues are discussed from the experimentalist's point of view in a predictive coding framework: (1) experimental protocols and procedures to control "refractoriness" effects; (2) methods to control attention; (3) vMMN and veridical perception. PMID:25278859

  17. Single-resonator double-negative metamaterial

    DOEpatents

    Warne, Larry K.; Basilio, Lorena I.; Langston, William L.; Johnson, William A.; Ihlefeld, Jon; Ginn, III, James C.; Clem, Paul G.; Sinclair, Michael B.

    2016-06-21

    Resonances can be tuned in dielectric resonators in order to construct single-resonator, negative-index metamaterials. For example, high-contrast inclusions in the form of metallic dipoles can be used to shift the first electric resonance down (in frequency) to the first magnetic resonance, or alternatively, air splits can be used to shift the first magnetic resonance up (in frequency) near the first electric resonance. Degenerate dielectric designs become especially useful in infrared- or visible-frequency applications where the resonator sizes associated with the lack of high-permittivity materials can become of sufficient size to enable propagation of higher-order lattice modes in the resulting medium.

  18. Mechanism of branching in negative ionization fronts.

    PubMed

    Arrayás, Manuel; Fontelos, Marco A; Trueba, José L

    2005-10-14

    When a strong electric field is applied to nonconducting matter, narrow channels of plasma called streamers may form. Branchlike patterns of streamers have been observed in anode directed discharges. We explain a mechanism for branching as the result of a balance between the destabilizing effect of impact ionization and the stabilizing effect of electron diffusion on ionization fronts. The dispersion relation for transversal perturbation of a planar negative front is obtained analytically when the ratio D between the electron diffusion coefficient and the intensity of the externally imposed electric field is small. We estimate the spacing lambda between streamers and deduce a scaling law lambda approximately D(1/3). PMID:16241810

  19. Negative reinforcement impairs overnight memory consolidation.

    PubMed

    Stamm, Andrew W; Nguyen, Nam D; Seicol, Benjamin J; Fagan, Abigail; Oh, Angela; Drumm, Michael; Lundt, Maureen; Stickgold, Robert; Wamsley, Erin J

    2014-11-01

    Post-learning sleep is beneficial for human memory. However, it may be that not all memories benefit equally from sleep. Here, we manipulated a spatial learning task using monetary reward and performance feedback, asking whether enhancing the salience of the task would augment overnight memory consolidation and alter its incorporation into dreaming. Contrary to our hypothesis, we found that the addition of reward impaired overnight consolidation of spatial memory. Our findings seemingly contradict prior reports that enhancing the reward value of learned information augments sleep-dependent memory processing. Given that the reward followed a negative reinforcement paradigm, consolidation may have been impaired via a stress-related mechanism. PMID:25320351

  20. Lower body negative pressure, experiment M092

    NASA Technical Reports Server (NTRS)

    Johnson, R. L.; Nicogossian, A. E.; Jackson, M. M.; Hoffler, G. W.; Wolthuis, R. A.

    1973-01-01

    Evaluation of orthostatic intolerance has been achieved by the use of lower body negative pressure (LBNP). The LBNP technique, though independent of gravity, simulates its effect by exposing the legs and the lower abdomen to reduced ambient pressures. This LBNP experiment, conducted during the 56-day simulation of the Skylab environment, was designed to supply baseline information on cardiovascular responses to periodic orthostatic stress. Impaired orthostatic tolerance, manifested by the increased heart rate, diminished systolic and pulse pressure, and increased tendency to syncope in the upright position, or during LBNP, was not observed in this experiment.