Science.gov

Sample records for 19e congrs mondial

  1. World heritage site - Bien du Patrimoine Mondial - Kluane/Wrangell-St. Elias/Glacier Bay/Tatshenshini-Alsek

    USGS Publications Warehouse

    Labay, Keith A.; Wilson, Frederic H.

    2004-01-01

    The four parks depicted on this map make up a single World Heritage Site that covers 24.3 million acres. Together, they comprise the largest internationally protected land-based ecosystem on the planet. The United Nations Educational, Scientific and Cultural Organization (UNESCO) established the World Heritage Program in 1972 for the identification and protection of the world?s irreplaceable natural and cultural resources. World Heritage Sites are important as storehouses of memory and evolution, as anchors for sustainable tourism and community, and as laboratories for the study and understanding of the earth and culture. This World Heritage Site protects the prominent mountain ranges of Kluane, Wrangell, Saint Elias, and Chugach. It includes many of the tallest peaks on the continent, the world's largest non-polar icefield, extensive glaciers, vital watersheds, and expanses of dramatic wilderness. [Les quatre parcs figurant sur cette carte ne constituent qu?un seul site du patrimoine mondial recouvrant plus de 99 millions de km2, ce qui en fait le plus grand ecosysteme terrestre protege par loi internationale. En 1972, L?UNESCO (l?organisation des Nations Unies pour les sciences, l'education et la culture) a etabli le programme du patrimoine mondial afin d?identifier et de proteger les ressources naturelles et culturelles irremplacables de notre plan?te. Si les sites du patrimoine mondial sont si importants c'est parce qu'ils representent a la fois des livres ouverts sur l?histoire de la Terre, le point de depart du tourisme durable et du developpement des collectivites, des laboratoires pour etudier et comprendre la nature et la culture. Ce site du patrimoine mondial assure la protection des chaines de montagnes de Kluane, Wrangell, Saint Elias, et Chugach. On y trouve plusieurs des plus hauts sommets du continent, le plus grand champ de glace non-polaire du monde, d?immenses glaciers, des bassins hydrologiques essentiels, et de la nature sauvage a perte de vue.

  2. Searching for a correlation between cosmic-ray sources above 10{sup 19} eV and large scale structure

    SciTech Connect

    Kashti, Tamar; Waxman, Eli E-mail: eli.waxman@weizmann.ac.il

    2008-05-15

    We study the anisotropy signature which is expected if the sources of ultrahigh energy, >10{sup 19} eV, cosmic rays (UHECRs) are extra-galactic and trace the large scale distribution of luminous matter. Using the PSCz galaxy catalog as a tracer of the large scale structure (LSS), we derive the expected all sky angular distribution of the UHECR intensity. We define a statistic that measures the correlation between the predicted and observed UHECR arrival direction distributions, and show that it is more sensitive to the expected anisotropy signature than the power spectrum and the two-point correlation function. The distribution of the correlation statistic is not sensitive to the unknown redshift evolution of UHECR source density and to the unknown strength and structure of inter-galactic magnetic fields. We show, using this statistic, that recently published >5.7 Multiplication-Sign 10{sup 19} eV Auger data are inconsistent with isotropy at Asymptotically-Equal-To 98% CL, and consistent with a source distribution that traces LSS, with some preference for a source distribution that is biased with respect to the galaxy distribution. The anisotropy signature should be detectable also at lower energy, >4 Multiplication-Sign 10{sup 19} eV. A few-fold increase of the Auger exposure is likely to increase the significance to >99% CL, but not to>99.9% CL (unless the UHECR source density is comparable to or larger than that of galaxies). In order to distinguish between different bias models, the systematic uncertainty in the absolute energy calibration of the experiments should be reduced to well below the current Asymptotically-Equal-To 25%.

  3. Absolute vibrational cross sections for 1-19 eV electron scattering from condensed tetrahydrofuran (THF)

    NASA Astrophysics Data System (ADS)

    Lemelin, V.; Bass, A. D.; Cloutier, P.; Sanche, L.

    2016-02-01

    Absolute cross sections (CSs) for vibrational excitation by 1-19 eV electrons impacting on condensed tetrahydrofuran (THF) were measured with a high-resolution electron energy loss spectrometer. Experiments were performed under ultra-high vacuum (3 × 10-11 Torr) at a temperature of about 20 K. The magnitudes of the vibrational CSs lie within the 10-17 cm2 range. Features observed near 4.5, 9.5, and 12.5 eV in the incident energy dependence of the CSs were compared to the results of theoretical calculations and other experiments on gas and solid-phase THF. These three resonances are attributed to the formation of shape or core-excited shape resonances. Another maximum observed around 2.5 eV is not found in the calculations but has been observed in gas-phase studies; it is attributed to the formation of a shape resonance.

  4. Observation of the suppression of the flux of cosmic rays above 4 x 10 (19) eV.

    PubMed

    Abraham, J; Abreu, P; Aglietta, M; Aguirre, C; Allard, D; Allekotte, I; Allen, J; Allison, P; Alvarez-Muñiz, J; Ambrosio, M; Anchordoqui, L; Andringa, S; Anzalone, A; Aramo, C; Argirò, S; Arisaka, K; Armengaud, E; Arneodo, F; Arqueros, F; Asch, T; Asorey, H; Assis, P; Atulugama, B S; Aublin, J; Ave, M; Avila, G; Bäcker, T; Badagnani, D; Barbosa, A F; Barnhill, D; Barroso, S L C; Baughman, B; Bauleo, P; Beatty, J J; Beau, T; Becker, B R; Becker, K H; Bellido, J A; Benzvi, S; Berat, C; Bergmann, T; Bernardini, P; Bertou, X; Biermann, P L; Billoir, P; Blanch-Bigas, O; Blanco, F; Blasi, P; Bleve, C; Blümer, H; Bohácová, M; Bonifazi, C; Bonino, R; Brack, J; Brogueira, P; Brown, W C; Buchholz, P; Bueno, A; Burton, R E; Busca, N G; Caballero-Mora, K S; Cai, B; Camin, D V; Caramete, L; Caruso, R; Carvalho, W; Castellina, A; Catalano, O; Cataldi, G; Cazon, L; Cester, R; Chauvin, J; Chiavassa, A; Chinellato, J A; Chou, A; Chudoba, J; Chye, J; Clark, P D J; Clay, R W; Colombo, E; Conceição, R; Connolly, B; Contreras, F; Coppens, J; Cordier, A; Cotti, U; Coutu, S; Covault, C E; Creusot, A; Criss, A; Cronin, J; Curutiu, A; Dagoret-Campagne, S; Daumiller, K; Dawson, B R; de Almeida, R M; De Donato, C; de Jong, S J; De La Vega, G; Junior, W J M de Mello; Neto, J R T de Mello; De Mitri, I; de Souza, V; Del Peral, L; Deligny, O; Della Selva, A; Fratte, C Delle; Dembinski, H; Di Giulio, C; Diaz, J C; Diep, P N; Dobrigkeit, C; D'Olivo, J C; Dong, P N; Dornic, D; Dorofeev, A; Dos Anjos, J C; Dova, M T; D'Urso, D; Dutan, I; Duvernois, M A; Engel, R; Epele, L; Erdmann, M; Escobar, C O; Etchegoyen, A; Luis, P Facal San; Falcke, H; Farrar, G; Fauth, A C; Fazzini, N; Ferrer, F; Ferrero, A; Fick, B; Filevich, A; Filipcic, A; Fleck, I; Fracchiolla, C E; Fulgione, W; García, B; Gámez, D García; Garcia-Pinto, D; Garrido, X; Geenen, H; Gelmini, G; Gemmeke, H; Ghia, P L; Giller, M; Glass, H; Gold, M S; Golup, G; Albarracin, F Gomez; Berisso, M Gómez; Gonçalves, P; do Amaral, M Gonçalves; Gonzalez, D; Gonzalez, J G; González, M; Góra, D; Gorgi, A; Gouffon, P; Grassi, V; Grillo, A F; Grunfeld, C; Guardincerri, Y; Guarino, F; Guedes, G P; Gutiérrez, J; Hague, J D; Halenka, V; Hamilton, J C; Hansen, P; Harari, D; Harmsma, S; Harton, J L; Haungs, A; Hauschildt, T; Healy, M D; Hebbeker, T; Hebrero, G; Heck, D; Hojvat, C; Holmes, V C; Homola, P; Hörandel, J R; Horneffer, A; Hrabovský, M; Huege, T; Hussain, M; Iarlori, M; Insolia, A; Ionita, F; Italiano, A; Kaducak, M; Kampert, K H; Karova, T; Kasper, P; Kégl, B; Keilhauer, B; Kemp, E; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Knapik, R; Knapp, J; Koang, D-H; Krieger, A; Krömer, O; Kuempel, D; Kunka, N; Kusenko, A; La Rosa, G; Lachaud, C; Lago, B L; Lebrun, D; Lebrun, P; Lee, J; de Oliveira, M A Leigui; Letessier-Selvon, A; Leuthold, M; Lhenry-Yvon, I; López, R; Agüera, A Lopez; Bahilo, J Lozano; Lucero, A; García, R Luna; Maccarone, M C; Macolino, C; Maldera, S; Mancarella, G; Manceñido, M E; Mandat, D; Mantsch, P; Mariazzi, A G; Maris, I C; Falcon, H R Marquez; Martello, D; Martínez, J; Bravo, O Martínez; Mathes, H J; Matthews, J; Matthews, J A J; Matthiae, G; Maurizio, D; Mazur, P O; McCauley, T; McEwen, M; McNeil, R R; Medina, M C; Medina-Tanco, G; Melo, D; Menichetti, E; Menschikov, A; Meurer, C; Meyhandan, R; Micheletti, M I; Miele, G; Miller, W; Mollerach, S; Monasor, M; Ragaigne, D Monnier; Montanet, F; Morales, B; Morello, C; Moreno, J C; Morris, C; Mostafá, M; Muller, M A; Mussa, R; Navarra, G; Navarro, J L; Navas, S; Necesal, P; Nellen, L; Newman-Holmes, C; Newton, D; Nhung, P T; Nierstenhoefer, N; Nitz, D; Nosek, D; Nozka, L; Oehlschläger, J; Ohnuki, T; Olinto, A; Olmos-Gilbaja, V M; Ortiz, M; Ortolani, F; Ostapchenko, S; Otero, L; Pacheco, N; Selmi-Dei, D Pakk; Palatka, M; Pallotta, J; Parente, G; Parizot, E; Parlati, S; Pastor, S; Patel, M; Paul, T; Pavlidou, V; Payet, K; Pech, M; Pekala, J; Pelayo, R; Pepe, I M; Perrone, L; Pesce, R; Petrera, S; Petrinca, P; Petrov, Y; Pichel, A; Piegaia, R; Pierog, T; Pimenta, M; Pinto, T; Pirronello, V; Pisanti, O; Platino, M; Pochon, J; Privitera, P; Prouza, M; Quel, E J; Rautenberg, J; Redondo, A; Reucroft, S; Revenu, B; Rezende, F A S; Ridky, J; Riggi, S; Risse, M; Rivière, C; Rizi, V; Roberts, M; Robledo, C; Rodriguez, G; Martino, J Rodriguez; Rojo, J Rodriguez; Rodriguez-Cabo, I; Rodríguez-Frías, M D; Ros, G; Rosado, J; Roth, M; Rouillé-d'Orfeuil, B; Roulet, E; Rovero, A C; Salamida, F; Salazar, H; Salina, G; Sánchez, F; Santander, M; Santo, C E; Santos, E M; Sarazin, F; Sarkar, S; Sato, R; Scherini, V; Schieler, H; Schmidt, A; Schmidt, F; Schmidt, T; Scholten, O; Schovánek, P; Schroeder, F; Schulte, S; Schüssler, F; Sciutto, S J; Scuderi, M; Segreto, A; Semikoz, D; Settimo, M; Shellard, R C; Sidelnik, I; Siffert, B B; Sigl, G

    2008-08-01

    The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min. PMID:18764444

  5. Observation of the suppression of the flux of cosmic rays above 4x10^19eV

    SciTech Connect

    Abraham, J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.; /Wisconsin U., Milwaukee /Northeastern U. /Lisbon, IST /Lisbon, LIFEP

    2008-06-01

    The energy spectrum of cosmic rays above 2.5 x 10{sup 18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index {gamma} of the particle flux, J {proportional_to} E{sup {gamma}}, at energies between 4 x 10{sup 18} eV and 4 x 10{sup 19} eV is 2.69 {+-} 0.02(stat){+-}0.06(syst), steepening to 4.2 {+-} 0.4(stat){+-}0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuzmin.

  6. Peculiarities of the anisotropy of cosmic rays with E{sub 0} {>=} 10{sup 19} eV from Yakutsk EAS array data

    SciTech Connect

    Glushkov, A. V.

    2009-11-15

    The arrival directions of primary cosmic ray particles with energies E{sub 0} {>=} 10{sup 19} eV and zenith angles {theta} {<=} 60{sup o} recorded on the Yakutsk array over the period 1974-2009 are analyzed. These events separated by different time intervals are shown to have different global anisotropies.

  7. An upper limit to the photon fraction in cosmic rays above 10**19-eV from the Pierre Auger Observatory

    SciTech Connect

    Abraham, J.; Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allison, P.; Alvarez, C.; Alvarez-Muniz, J.; Ambrosio, M.; Anchordoqui, L.; Anjos, J.C.; /Centro Atomico Bariloche /Buenos Aires, CONICET /La Plata U. /Pierre Auger Observ. /CNEA, San Martin /Adelaide U. /Catholic U. of Bolivia, La Paz /Bolivia U. /Sao Paulo U. /Campinas State U. /UEFS, Feira de Santana

    2006-06-01

    An upper limit of 16% (at 95% c.l.) is derived for the photon fraction in cosmic rays with energies above 10{sup 19} eV, based on observations of the depth of shower maximum performed with the hybrid detector of the Pierre Auger Observatory. This is the first such limit on photons obtained by observing the fluorescence light profile of air showers. This upper limit confirms and improves on previous results from the Haverah Park and AGASA surface arrays. Additional data recorded with the Auger surface detectors for a subset of the event sample, support the conclusion that a photon origin of the observed events is not favored.

  8. SourceURL:file://localhost/Users/socquet/Auboulot/congres/socquetAGU2014.doc Geodetic coupling in the North Chile - South Peru seismic gap: new insights from GPS measurements in Peru

    NASA Astrophysics Data System (ADS)

    Socquet, A.; Cotte, N.; Norabuena, E. O.; Quiroz, W.; Jara, J.; Pina-Valdes, J.; Chlieh, M.; Carrizo, D.; Bejar Pizarro, M.; Metois, M.

    2014-12-01

    SourceURL:file://localhost/Users/socquet/Auboulot/congres/socquetAGU2014.doc The subduction zone at the latitude of the Central Andes did not experience a Mw>8.5 earthquake since the 19thcentury, and forms a ~500km long seismic gap in North Chile - South Peru. Understanding the factors that limit the extent of seismic ruptures is crucial for risk mitigation and for understanding physical processes that govern the behavior of seismogenic faults. It appears crucial to evaluate interseismic coupling and its spatial variation in seismic gaps to assess seismic potential. Recent geodetic studies combining continuous and campaign GPS measurements as well as InSAR measurements showed that the subduction interface in north Chile, was accumulating interseismic elastic strain, likely to rebound into a large megathrust Earthquake. A Mw8.2 earthquake occurred on the 1st of April 2014 in this seismic gap, in front of Pisagua (North Chile), ~150 km south of the Chile-Peru Border. In spite of its already large magnitude, that earthquake was smaller expected in the area, and has most probably increased the stress in the unbroken segments at both edges. Most of accumulated strain remains to be relaxed in the North Chile-South Peru seismic gap. Here we propose to present a first assessment of the interseismic loading in the South Peru part of the seismic gap, at the northern extremity of Pisagua Earthquake, where it is poorly known. In south Peru, over an area of 500 x 250 km, 33 campaign markers have been installed and measured in June 2012. This network has been partially remeasured in June 2013 and April 2014 (after Mw8.2 Pisagua Eaquake). These measurements provide us with an estimate of the Pre-Pisagua-Earthquake coupling, and the co-seismic static displacements. These displacements are combined together with the ones of previous studies that occurred in North Chile and provide a unique and dense velocity field spreading through the Chile Peru border. In particular this provides

  9. Site-selective laser-spectroscopy studies of the intrinsic 1.9-eV luminescence center in glassy SiO2

    NASA Astrophysics Data System (ADS)

    Skuja, Linards; Suzuki, Toshio; Tanimura, Katsumi

    1995-12-01

    The intrinsic 1.9-eV photoluminescence band (the R band) in neutron-irradiated synthetic silica glass has been studied using site-selective photoluminescence excitation in the 2.0 eV absorption band and transient spectral hole-burning techniques. The measurements of the low-energy wing of the zero-phonon line intensity distribution function confirm the predicted nearly Gaussian shape with a peak at 1.93 eV and a half-width of 86 meV. The homogeneous shape of the emission contour (``single-site spectrum'') has been evaluated by a selective saturation method, revealing, a phonon sideband with a peak at 60 cm-1 and a width of approximately 500 cm-1. The total Huang-Rhys factor is estimated as 1.50+/-0.5 and the partial Huang-Rhys factor for the interaction with the 890 cm-1 local vibration is 0.08+/-0.04. The analysis of spectral parameters indicates that the R band cannot be due to peroxide or ozonide molecular ions and upholds the attribution of the center to the nonbridging oxygen hole center.

  10. Acceptances for space-based and ground-based fluorescence detectors, and inference of the neutrino-nucleon cross-section above 10{sup 19} eV

    SciTech Connect

    Palomares-Ruiz, Sergio; Irimia, Andrei; Weiler, Thomas J.

    2006-04-15

    Detection of ultrahigh energy neutrinos will be useful for unraveling the dynamics of the most violent sources in the cosmos and for revealing the neutrino cross-section at extreme energy. If there exists a Greisen-Zatsepin-Kuz'min (GZK) suppression of cosmic-ray events above E{sub GZK}{approx}5x10{sup 19} eV, as predicted by theory, then the only messengers of energies beyond E{sub GZK} are neutrinos. Cosmic neutrino fluxes can initiate air-showers through interaction in the atmosphere, or in the Earth. Neutrino trajectories will be downgoing to nearly horizontal in the former case, and 'Earth-skimming' in the latter case. Thus it is important to know the acceptances (event rate/flux) of proposed air-shower experiments for detecting both types of neutrino-initiated events. We calculate these acceptances for fluorescence detectors, both space-based as with the EUSO and OWL proposals, and ground-based, as with Auger, HiRes and Telescope Array. The neutrino cross-section {sigma}{sub {nu}}{sub N}{sup CC} is unknown at energies above 5.2x10{sup 13} eV. Although the popular QCD extrapolation of lower-energy physics offers the cross-section value of 0.54x10{sup -31}(E{sub {nu}}/10{sup 20} eV){sup 0.36} cm{sup 2}, new physics could raise or lower this value. Therefore, we present the acceptances of horizontal (HAS) and upgoing (UAS) air-showers as a function of {sigma}{sub {nu}}{sub N}{sup CC} over the range 10{sup -34} to 10{sup -30} cm{sup 2}. The dependences of acceptances on neutrino energy, shower-threshold energy, shower length, and shower column density are also studied. We introduce a cloud layer, and study its effect on rates as viewed from space and from the ground. For UAS, we present acceptances for events over land (rock), and over the ocean (water). Acceptances over water are larger by about an order of magnitude, thus favoring space-based detectors. We revisit the idea of Kusenko and Weiler [Phys. Rev. Lett. 88, 161101 (2002)] to infer {sigma}{sub {nu

  11. Éthique de la recherche en santé mondiale : la relation Nord-Sud, quel partenariat pour quelle justice sociale ?

    PubMed

    Godard, Béatrice; Hunt, Matthew; Moube, Zéphirin

    2014-03-01

    La recherche en santé mondiale s'inscrit dans une volonté de mobiliser des connaissances au service d'interventions et de politiques publiques pour l'atteinte équitable du bien-être commun, notamment en matière de santé. Elle joue un rôle primordial en ce sens, en favorisant l'implication des communautés et leur autonomisation et de nombreuses lignes directrices supportent un tel partenariat. Néanmoins, certains enjeux éthiques sont liés au financement de la recherche, aux environnements de recherche, à la priorisation des problématiques de recherche, aux mécanismes d'évaluation éthique posent souvent un problème de justice sociale au niveau de la redistribution des ressources et de la reconnaissance des différences culturelles. Comment alors déterminer quelle est la façon « idéale » d'agir en tenant compte de la globalité des individus et du pluralisme culturel des sociétés pour « bien faire », pour satisfaire l'exigence de l'équité? Une réflexion et une démarche éthique demeurent essentielles, ainsi qu'un dialogue entre les chercheurs du Nord et du Sud, et leurs autres partenaires que sont les décideurs, les responsables locaux et les communautés. Un tel dialogue, établi dans un continuum du développement de projets de recherche à leur pérennité, peut grandement contribuer à limiter les problèmes de justice sociale et à viser un développement plus égalitaire des savoirs scientifiques. Plusieurs chercheurs se sont déjà engagés dans cette voie, et leurs initiatives devraient être encouragées pour mettre les nouveaux savoirs au service des populations. PMID:24594489

  12. Searches for large-scale anisotropy in the arrival directions of cosmic rays detected above energy of 10{sup 19} eV at the Pierre Auger observatory and the telescope array

    SciTech Connect

    Aab, A.; Abreu, P.; Andringa, S.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Asorey, H.; Allen, J.; Allison, P.; Almela, A.; Castillo, J. Alvarez; Alvarez-Muñiz, J.; Batista, R. Alves; Ambrosio, M.; Aramo, C.; Aminaei, A.; Anchordoqui, L.; Arqueros, F.; Collaboration: Pierre Auger Collaboration; Telescope Array Collaboration; and others

    2014-10-20

    Spherical harmonic moments are well-suited for capturing anisotropy at any scale in the flux of cosmic rays. An unambiguous measurement of the full set of spherical harmonic coefficients requires full-sky coverage. This can be achieved by combining data from observatories located in both the northern and southern hemispheres. To this end, a joint analysis using data recorded at the Telescope Array and the Pierre Auger Observatory above 10{sup 19} eV is presented in this work. The resulting multipolar expansion of the flux of cosmic rays allows us to perform a series of anisotropy searches, and in particular to report on the angular power spectrum of cosmic rays above 10{sup 19} eV. No significant deviation from isotropic expectations is found throughout the analyses performed. Upper limits on the amplitudes of the dipole and quadrupole moments are derived as a function of the direction in the sky, varying between 7% and 13% for the dipole and between 7% and 10% for a symmetric quadrupole.

  13. On the anisotropy of E{sub 0} Greater-Than-Or-Slanted-Equal-To 5.5 Multiplication-Sign 10{sup 19} eV cosmic rays according to data of the Pierre Auger Collaboration

    SciTech Connect

    Glushkov, A. V.

    2012-02-15

    The Pierre Auger Collaboration discovered, in a solid angle of radius about 18 Degree-Sign , a local group of cosmic rays having energies in the region E{sub 0} {>=} 5.5 Multiplication-Sign 10{sup 19} eV and coming from the region of the Gen A radio galaxy, whose galactic coordinates are l{sub G} 309.5 Degree-Sign and b{sub G} = 19.4 Degree-Sign . Near it, there is the Centaur supercluster of galaxies, its galactic coordinates being l{sub G} = 302.4 Degree-Sign and b{sub G} = 21.6 Degree-Sign . It is noteworthy that the Great Attractor, which may have a direct bearing on the observed picture, is also there.

  14. Translation into French of: “Changes to publication requirements made at the XVIII International Botanical Congress in Melbourne – what does e-publication mean for you?”. Translated by Christian Feuillet and Valéry Malécot Changements des conditions requises pour la publication faits au XVIII e Congrès International de Botanique à Melbourne – qu’est-ce que la publication électronique représente pour vous?

    PubMed Central

    Knapp, Sandra; McNeill, John; Turland, Nicholas J.

    2011-01-01

    Résumé Les changements au Code International de Nomenclature Botanique sont décidés tous les 6 ans aux Sections de Nomenclature associées aux Congrès Internationaux de Botanique (CIB). Le XVIIIe CIB se tenait à Melbourne, Australie; la Section de Nomenclature s’est réunie les 18-22 juillet 2011 et ses décisions ont été acceptées par le Congrès en session plénière le 30 juillet. Suite à cette réunion, plusieurs modifications importantes ont été apportées au Code et vont affecter la publication de nouveaux noms. Deux de ces changements prendront effet le 1er janvier 2012, quelques mois avant que le Code de Melbourne soit publié. Les documents électroniques publiés en ligne en ‘Portable Document Format’ (PDF) avec un ‘International Standard Serial Number’ (ISSN) ou un ‘International Standard Book Number’ (ISBN) constitueront une publication effective, et l’exigence d’une description ou d’une diagnose en latin pour les noms des nouveaux taxa sera changée en l’exigence d’une description ou d’une diagnose en latin ou en anglais. De plus, à partir du 1er janvier 2013, les noms nouveaux des organismes traités comme champignons devront, pour que la publication soit valide, inclure dans le protologue (tous ce qui est associé au nom au moment de la publication valide) la citation d’un identifiant (‘identifier’) fourni par un dépôt reconnu (tel MycoBank). Une ébauche des nouveaux articles concernant la publication électronique est fournie et des conseils de bon usage sont esquissés. Pour encourager la diffusion des changements adoptés au Code International de Nomenclature pour les algues, les champignons et les plantes, cet article sera publié dans BMC Evolutionary Biology, Botanical Journal of the Linnean Society, Brittonia, Cladistics, MycoKeys, Mycotaxon, New Phytologist, North American Fungi, Novon, Opuscula Philolichenum, PhytoKeys, Phytoneuron, Phytotaxa, Plant Diversity and Resources, Systematic Botany et

  15. Translation into French of: "Changes to publication requirements made at the XVIII International Botanical Congress in Melbourne - what does e-publication mean for you?". Translated by Christian Feuillet and Valéry Malécot Changements des conditions requises pour la publication faits au XVIII Congrès International de Botanique à Melbourne - qu'est-ce que la publication électronique représente pour vous?

    PubMed

    Knapp, Sandra; McNeill, John; Turland, Nicholas J

    2011-01-01

    RésuméLes changements au CodeInternational de Nomenclature Botanique sont décidés tous les 6 ans aux Sections de Nomenclature associées aux Congrès Internationaux de Botanique (CIB). Le XVIII(e) CIB se tenait à Melbourne, Australie; la Section de Nomenclature s'est réunie les 18-22 juillet 2011 et ses décisions ont été acceptées par le Congrès en session plénière le 30 juillet. Suite à cette réunion, plusieurs modifications importantes ont été apportées au Code et vont affecter la publication de nouveaux noms. Deux de ces changements prendront effet le 1(er) janvier 2012, quelques mois avant que le Code de Melbourne soit publié. Les documents électroniques publiés en ligne en 'Portable Document Format' (PDF) avec un 'International Standard Serial Number' (ISSN) ou un 'International Standard Book Number' (ISBN) constitueront une publication effective, et l'exigence d'une description ou d'une diagnose en latin pour les noms des nouveaux taxa sera changée en l'exigence d'une description ou d'une diagnose en latin ou en anglais. De plus, à partir du 1(er) janvier 2013, les noms nouveaux des organismes traités comme champignons devront, pour que la publication soit valide, inclure dans le protologue (tous ce qui est associé au nom au moment de la publication valide) la citation d'un identifiant ('identifier') fourni par un dépôt reconnu (tel MycoBank). Une ébauche des nouveaux articles concernant la publication électronique est fournie et des conseils de bon usage sont esquissés.Pour encourager la diffusion des changements adoptés au Code International de Nomenclature pour les algues, les champignons et les plantes, cet article sera publié dans BMC Evolutionary Biology, Botanical Journal of the Linnean Society, Brittonia, Cladistics, MycoKeys, Mycotaxon, New Phytologist, North American Fungi, Novon, Opuscula Philolichenum, PhytoKeys, Phytoneuron, Phytotaxa, Plant Diversity and Resources, Systematic Botany et Taxon. PMID:22287925

  16. Allogeneic stem cell transplantation improves the outcome of adults with t(1;19)/E2A-PBX1 and t(4;11)/MLL-AF4 positive B-cell acute lymphoblastic leukemia: results of the prospective multicenter LALA-94 study.

    PubMed

    Vey, N; Thomas, X; Picard, C; Kovascovicz, T; Charin, C; Cayuela, J M; Dombret, H; Dastugue, N; Huguet, F; Bastard, C; Stamatoulas, A; Giollant, M; Tournilhac, O; Macintyre, E; Buzyn, A; Bories, D; Kuentz, M; Dreyfus, F; Delannoy, A; Raynaud, S; Gratecos, N; Bordessoule, D; de Botton, S; Preudhomme, C; Reman, O; Troussard, X; Pigneux, A; Bilhou, C; Vernant, J P; Boucheix, C; Gabert, J

    2006-12-01

    Adult patients with acute lymphoblastic leukemia (ALL) and t(1;19)/E2A-PBX1 or t(4;11)/MLL-AF4 have a poor outcome. We have evaluated the impact of an intensified post-remission therapy using a high-dose chemotherapy course followed by allogeneic or autologous SCT on the outcome of 58 patients with t(1;19)/E2A-PBX1 (E2A group, n=24) or t(4;11)/MLL-AF4 (MLL group, n=34) treated in the LALA-94 multicenter prospective study. Patients in the MLL group had higher WBC counts and more frequent DIC. CR rates achieved by MLL and E2A groups were similar to other B-cell ALL (87, 82 and 86% respectively). While in CR, patients with a donor were assigned to alloSCT (n=22), the remaining patients with were randomized between autoSCT (n=15) or chemotherapy (n=8). Five-year overall survival was 31 and 45% for E2A and MLL groups, respectively. In both groups, DFS was higher in the alloSCT arm as compared to autoSCT and chemotherapy arms. The results of this study show that chemotherapy intensification did not overcome the poor prognosis of adults with t(1;19)/E2A-PBX1. Allogeneic SCT should thus be offered in first CR to patients with t(1;19)/E2A-PBX1 or t(4;11)/MLL-AF4. New therapeutic approaches are needed for patients without donor. PMID:17039234

  17. Synthesis, structural characterization, superoxide dismutase and antimicrobial activities studies of copper (II) complexes with 2-(E)-(2-(2-aminoethylamino) methyl)-4-bromophenol and (19E, 27E)-N1, N2-bis (phenyl (pyridine-2-yl)-methylene)-ethane-1, 2-diamine as ligands

    NASA Astrophysics Data System (ADS)

    Choudhary, Mukesh; Patel, R. N.; Rawat, S. P.

    2014-07-01

    Three new copper (II) complexes, [Cu(L)(H2O)]ClO4 (1), [Cu(L1)(ClO4)]+ (2) and [Cu(L1)]2+ (3), where HL = 2-(E)-(2-(2-aminoethylamino)methyl)-4-bromophenol, L1 =(19E, 27E)-N1,N2-bis(phenyl(pyridine-2-yl)-methylene)-ethane-1, 2-diamine, have been synthesized and characterized by using various physic-chemical and spectroscopic methods. The solid-state structures of 1 and 2 were determined by single crystal X-ray crystallography. Infrared spectra, ligand field spectra and magnetic susceptibility measurements agree with the observed crystal structures. The molecular structure of copper complexes showed that the ligands occupies the basal plane of square pyramidal geometry with the H2O of 1 or the ClO4 of 2 occupying the remaining apical position. Complexes 1 and 2 crystallize in the monoclinic system of the space group P21/c, a = 10.5948(6)Å, b = 19.6164(11)Å, c = 8.6517(5)Å, α = 90°, β = 108.213(2)°, γ = 90° and Z = 4 for 1, a = 9.5019(3)Å, b = 11.3 801(3)Å, c = 25.3168(14)Å, α = 90°, β = 100.583(4)°, γ = 90°, and Z = 4 for 2. The synthesized Schiff base (HL/L1) was behaves as tetradentate ON3/N4 ligands with donor groups suitable placed for forming 2 or 3 five membered chelate rings. Copper (II) complexes display X-band EPR spectra in 100% DMSO at 77 K giving g|| > g⊥ > 2.0023 indicating dx2-y2 ground state. The half-wave potential values for Cu (II)/Cu (I) redox couple obtained in the reaction of the copper (II) complexes with molecular oxygen and superoxide radical (O2-) electronegated in DMSO are in agreement with the SOD-like activity of the copper (II) complexes. In vitro antimicrobial activities of the complexes against the two bacteria (Escherichia coli, Salmonella typhi) and the two fungi (Penicillium, Aspergillus sp.) have been investigated comparing with the Schiff base ligands.

  18. CONGR: A FORTRAN IV Program to Compute Coefficients of Congruence for Factor Analysis

    ERIC Educational Resources Information Center

    Myers, Donald E.

    1976-01-01

    A Fortran IV program which computes either of the coefficients of congruence (psi or phi) used in comparison of factors in factor analysis is presented. Output consists of a non-symmetric matrix of factor coefficients. Listings of the program, results and test data are available. (Author/JKS)

  19. On galactic origin of cosmic rays with energy up to 10(19) eV

    NASA Technical Reports Server (NTRS)

    Mikhailov, A. A.; Efimov, N. N.

    1985-01-01

    The experimental data on ultrahigh energy cosmic ray anisotropy are considered. In supposed models of galactic magnetic field the main characteristics of expected anisotropy are estimated and are compared with the experimental data. It is shown that particles with energy up to 10 to the 19th power eV are of galactic origin.

  20. Properties of 10 (18)-10 (19)eV EAS at far core distance

    NASA Technical Reports Server (NTRS)

    Hara, T.; Hatano, Y.; Ishikawa, F.; Kamata, K.; Matsubara, Y.; Teshima, M.; Nagano, M.; Hayashida, N.; He, C. X.; Honda, M.

    1985-01-01

    The properties of 10 to the 18th power - 10 to the 19th power eV EAS showers such as the electron lateral distribution, the muon lateral distribution ( 1Gev), the ratio of muon density to a electron density, the shower front structure and the transition effects in scintillator of 5cm thickness are investigated with the Akeno 4 sq km/20sq km array at far core distances between 500m and 3000m. The fluctuation of densities and arrival time increase rapidly at core distances greater than 2km.

  1. Comments on the workshop on techniques to study cosmic rays with E>10 19eV

    NASA Astrophysics Data System (ADS)

    Ducorps, Antoine

    1992-11-01

    As a software engineer with a background in electronics, working in the area of High Energy Physics, I feel embarrassed to give my views on this Workshop which is in a field very novel to me. However, I would like to comment on three points, amongst the huge quantity of knowledge handed to me during these three days.

  2. Proceedings of the Annual Conference of the Canadian Communication Association (Ottawa, Ontario, Canada, 1993) = Actes du Congres annuel, Association Canadienne de Communication (Ottawa, Ontario, Canada, 1993).

    ERIC Educational Resources Information Center

    Canadian Communication Association, Montreal (Quebec).

    This paper presents abstracts of 80 individual papers and panel discussions that deal with journalism, popular culture, mass media, "science" in public discourse, the social construction of communication technologies, factorial analysis as a research tool, and other issues in communication. Almost all of the abstracts in the paper are presented in…

  3. Ninth international congress on Carboniferous stratigraphy and geology. Proceedings, volume 3. Neuvieme congres international de stratigraphie et de geologie du Carbonifere. Compte rendu, volume 3

    SciTech Connect

    Geldsetzer, H.H.J.; Nassichuk, W.W.; Belt, E.S.; Macqueen, R.W.

    1984-01-01

    Papers were presented on the Carboniferous stratigraphy of the Atlantic Coast basins, on paleogeography and paleotectonics and on sedimentology and geochemistry. A total of 14 papers concerning coal have been abstracted separately. Papers are in English or in French.

  4. Ninth international congress on Carboniferous stratigraphy and geology. Neuvieme congres international de stratigraphie et de geologie du Carbonifere. Compte rendu, volume 1

    SciTech Connect

    Gordon, M.

    1984-01-01

    This volume contains: the plenary sessions of the Congress; invited lectures on the Carboniferous geology of China and Spain; reports of international commissions and committees; and papers on the history of Carboniferous geology. 4 papers have been abstracted separately.

  5. Le Congres de Nice 1974: Encouragement des Activites des Ecrivains at Traducteurs (The Nice Congress 1974: Encouraging the Activities of Writers and Translators)

    ERIC Educational Resources Information Center

    De Azaola, M.

    1974-01-01

    A representative from Unesco offers some suggestions supporting writers and translators, including: strong writers' organizations, literature prizes, encouraging writers from oral traditions to record work on tape, diversification of production by publishers, financial rewards to writers from both government and publishers, and adherence to…

  6. The World Bank and the environment, fiscal 1992, exercise 92. Annual report. Banque mondiale et l'environnement, ejercicio 92

    SciTech Connect

    Not Available

    1992-09-01

    The report describes the Bank's activities in assisting countries with environmental management, such as programs to reduce poverty without exhausting natural resources. Included are assessments of the environmental impacts of projects supported by World Bank loans, and accounts of efforts to meet global environmental challenges with coordinated international action through the Global Environment Facility (GEF). Among the events in the period covered by the report are the affirmation of the World Bank's participation with United Nations organizations in the GEF and the Bank's administration of pilot programs aimed at finding solutions to such global environmental problems as pollution of international waters, global warming, depletion of the Earth's ozone layer, and dwindling biological diversity; the United Nations Conference on Environment and Development; and the publication of the World Development Report 1992, with its theme of development and the environment.

  7. Parente genetique et correspondances phonetiques: A propos du proto-mondial (Genetic Kinship and Phonetic Correspondences: About Proto-Global).

    ERIC Educational Resources Information Center

    Jucquois, Guy

    2001-01-01

    Irrespective of the traditional reconstructions related to the theory of well known families of languages such as Indo-European or Semitic, some researchers have aimed at rebuilding super-families, going as far as a Proto-global family. Several puzzling agreements between their proposals and the reconstructions made by the genetics populations…

  8. Initial Results from a Search for Lunar Radio Emission from Interactions of >= 10(exp 19) eV Neutrinos and Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Gorham, P. W.; Liewer, K. M.; Naudet, C. J.

    2000-01-01

    Using the NASA Goldstone 70m antenna DSS 14 both singly and in coincidence with the 34 m antenna DSS 13 (21.7 km to the southeast), we have acquired approximately 12 hrs of livetime in a search for predicted pulsed radio emission from extremely-high energy cascades induced by neutrinos or cosmic rays in the lunar regolith. In about 4 hrs of single antenna observations, we reduced our sensitivity to impulsive terrestrial interference to a negligible level by use of a veto afforded by the unique capability of DSS 14. In the 8 hrs of dual-antenna observations, terrestrial interference is eliminated as a background. In both observing modes the thermal noise floor limits the sensitivity. We detected no events above statistical background. We report here initial limits based on these data which begin to constrain several predictions of the flux of EHE neutrinos.

  9. Colleges Celebrations 92: Actes du Congres = College Celebrations 92: Proceedings of the Combined Conference of the Association des colleges communacutaires du Canada and the Association quebecoise de pedagogie collegiale (Montreal, Quebec, May 24-27, 1992).

    ERIC Educational Resources Information Center

    Association of Canadian Community Colleges.

    The papers presented at this meeting of the annual conference of the Quebec Association of Collegiate Pedagogy and the Association of Canadian Community Colleges covered the following topics: (1) Students and Teachers, including papers focusing on faculty and student characteristics and concerns; (2) Development of Human Resources, including…

  10. Equal Employment Opportunity Law Enforcement. Hearing before the Subcommittee on Employment Opportunities of the Committee on Education and Labor. House of Representatives. One Hundredth Congres, Second Session (Los Angeles, CA).

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on Education and Labor.

    This document comprises the testimony presented at an oversight hearing on equal employment opportunity law enforcement before the House Subcommittee on Employment Opportunities. Among those who testified were the following: (1) Jerry Blakemore, Office of Federal Contract Compliance Programs, United States Department of Labor; (2) James Foster,…

  11. Discours prononce au cours du diner offert a l'issue du premier congres de l'API (Address Given on the Occasion of the First Meeting of the API)

    ERIC Educational Resources Information Center

    Spicer, Keith

    1978-01-01

    The speech, half in French and half in English, is an endorsement of the association, an indication of political, social and educational reforms it might influence, a reminder that members of the association, Canadian Parents for French, were present and interested, and an appeal for good public relations. (AMH)

  12. Repertoire Mondial des Collections et des Fonds d'Archives de l'Art des Enfants = World Directory of Collections and Archives of Children's Art.

    ERIC Educational Resources Information Center

    Lambert, Nancy R.; And Others

    Divided into two parts, this world directory features collections and archives of childrens' art. The first part of the volume provides information about the collections before October 1989. Entries are arranged in alphabetical order according to the French spelling of the various countries and include the following information for each entry:…

  13. Eduard Suess (1831 1914) et sa fresque mondiale La face de la Terre, deuxième tentative de tectonique globale

    NASA Astrophysics Data System (ADS)

    Durand-Delga, Michel; Seidl, Johannes

    2007-01-01

    The global synthesis of Suess, Das Antlitz der Erde (1883-1909), translated and augmented as La face de la Terre, replaces Élie de Beaumont's theory of 'upheavals', rejected by the end of the century. Although Suess' theory is also based upon the alleged cooling of the Earth, it differs on significant points such as the following: ( i) mountain belts are not symmetrical, they result from tangential push directed towards their foreland; ( ii) their bends result from their accommodation against older rigid blocks; ( iii) the 'Caledonian belt' has been followed by the 'Variscan', in turn followed by the 'Alpides' (see Marcel Bertrand); ( iv) the oceans formed by foundering of their basement at varied epochs, and their progressive infilling resulted in the worldwide 'eustatic' transgressions; ( v) the peri-Pacific 'island arcs' move toward the Pacific Ocean, which is the oldest one. Besides a coherent vision of the development of the Earth, integrating the early concepts of 'mobilism', Suess coined many currently used geological terms (Tethys, Gondwana, etc.). Suess, at this time authoritative the world over, was a member of the 'Académie des sciences' of Paris.

  14. Searches for Large-Scale Anisotropy in the Arrival Directions of Cosmic Rays Detected above Energy of $10^{19}$ eV at the Pierre Auger Observatory and the Telescope Array

    SciTech Connect

    Aab, Alexander; et al,

    2014-10-07

    Spherical harmonic moments are well-suited for capturing anisotropy at any scale in the flux of cosmic rays. An unambiguous measurement of the full set of spherical harmonic coefficients requires full-sky coverage. This can be achieved by combining data from observatories located in both the northern and southern hemispheres. To this end, a joint analysis using data recorded at the Telescope Array and the Pierre Auger Observatory above 1019 eV is presented in this work. The resulting multipolar expansion of the flux of cosmic rays allows us to perform a series of anisotropy searches, and in particular to report on the angular power spectrum of cosmic rays above 1019 eV. No significant deviation from isotropic expectations is found throughout the analyses performed. Upper limits on the amplitudes of the dipole and quadrupole moments are derived as a function of the direction in the sky, varying between 7% and 13% for the dipole and between 7% and 10% for a symmetric quadrupole.

  15. Education for All: Is the World on Track? Summary Report. EFA Global Monitoring Report, 2002 = Education pour Tous: Le Monde Est-Il sur la Bonne Voie? Resume du Rapport. Rapport Mondial de Suivi sur l'EPT, 2002.

    ERIC Educational Resources Information Center

    Colclough, Christopher; Packer, Steve; Ellis, Simon; Van Ravens, Jan; Barry, Ulrika Peppler; Bella, Nicole; Djioze, Valerie; Mputu, Hilaire; Aggio, Carlos; Cifuentes-Montoya, Mariana; Pinceau, Pascale; Nsengimana, Delphine

    In 2000 the World Education Forum, sponsored by UNESCO, met to assess and act on educational opportunities for children, youth, and adults around the world. The forum agreed on six goals for education considered to be essential, attainable, and affordable, given strong international commitment and resolve, and on a program called Education for All…

  16. Proceedings of the Annual Conference of the Canadian Association for the Study of Adult Education = Les actes du congres annuel de l'association canadienne pour l'etude de l'education des adultes (8th, Cornwall, Ontario, June 1-30, 1989).

    ERIC Educational Resources Information Center

    Bedard, Rene, Ed.

    This proceedings contains 23 papers in French and the following 45 papers in English: "Arthur Lismer" (Barer-Stein); "Bootstrapping and Shoestringing to Academic Respectability" (Baskett); "Teaching by Teleconference" (Boak, Kirby); "Doing What Is Possible" (Butterwick); "Connections between Individual and World Peace" (Fallis et al.); "Federal…

  17. Efficacité de la prévention de la transmission mère-enfant du Virus de l'Immunodéficience Humaine par le protocole 2010 de l'Organisation Mondiale de la Santé au Centre Médical Saint Camille de Ouagadougou (Burkina Faso)

    PubMed Central

    OuédraogoYugbaré, Solange Odile; Zagré, Nikaise; Koueta, Fla; Dao, Lassina; Kam, Ludovic; Ouattara, Diarra Yé; Simporé, Jacques

    2015-01-01

    L’épidémie du Virus de l'Immunodéficience Humaine en milieu pédiatrique est surtout le résultat de la transmission mère-enfant. Notre étude a pour objectif de décrire l'efficacité de la prévention de la transmission mère-enfant du Virus de l'Immunodéficience Humaine par le protocole OMS 2010 (Option A et trithérapie) au centre médical saint Camille de Ouagadougou. Nous avons mené une étude d'une cohorte d'enfants suivis dans le cadre de la prévention de la transmission mère-enfant du Virus de l'Immunodéficience Humaine au centre médical saint Camille de Ouagadougou sur une période de 2 ans allant du 1er Janvier 2012 au 31 Décembre 2013. Nous avons obtenu l'accord de 4900 femmes enceintes pour le dépistage de l'infection du Virus de l'Immunodéficience Humaine et 238 gestantes ont été diagnostiquées séropositives soit 4,86% de séroprévalence. Les femmes étaient surtout infectées par le Virus de l'Immunodéficience Humaine avec de type I (95,38%)). La majorité était sous trithérapie (74,3%) et (25,7%) sous prophylaxie (option A). Les nouveau-nés (92,5%) ont reçu un traitement antirétroviral à base de névirapine dans les 72 heures après la naissance. L'allaitement sécurisé a été appliquée dans 78% des cas. Le taux global de transmission mère-enfant du VIH était de 3,6% avec 3% de transmission chez les enfants nés de mères sous trithérapie antirétrovirale et 6,3% dans les cas de prophylaxie antirétrovirale. Le facteur de risque de transmission a été le long délai du début d'administration des antirétroviraux chez le nouveau-né. La mortalité infantile à un an était de 3,5%. Cette étude a révélé l'efficacité de l'Option A et conforté celle de la trithérapie, le passage à l'Option B+ serait donc plus bénéfique. PMID:26966499

  18. Early Childhood Education and Care in the 21st Century: Global Guidelines and Papers from an International Symposium Hosted by the World Organization for Early Childhood Education (Organisation Mondiale pour L'Education Prescolaire) and the Association for Childhood Education International (Ruschlikon, Switzerland, July 5-8, 1999).

    ERIC Educational Resources Information Center

    Association for Childhood Education International, Olney, MD.

    The International Symposium on Early Childhood Education and Care for the 21st Century was held in Ruschlikon, Switzerland in 1999. Attending were 83 early childhood education professionals from 28 nations to develop international guidelines for the education and care of young children. This document contains shortened versions of the guidelines…

  19. Comparison of selected animal observations and management practices used to assess welfare of calves and adult dairy cows on organic and conventional dairy farms.

    PubMed

    Bergman, M A; Richert, R M; Cicconi-Hogan, K M; Gamroth, M J; Schukken, Y H; Stiglbauer, K E; Ruegg, P L

    2014-07-01

    Differences in adoption of selected practices used in welfare assessment and audit programs were contrasted among organic (ORG; n=192) herds and similarly sized conventional grazing herds (CON-GR; n=36), and conventional nongrazing herds (CON-NG; n=64). Criteria from 3 programs were assessed: American Humane Association Animal Welfare Standards for Dairy Cattle, Farmers Assuring Responsible Management (FARM), and the Canadian Codes of Practice (CCP). Data were collected by trained study personnel during a herd visit and included information about neonatal care, dehorning, pain relief, calf nutrition, weaning, record keeping, use of veterinarians, and animal observations. Associations of management type (ORG, CON-GR, or CON-NG) with adoption of selected practice were assessed. Almost all farms (97%) met criteria suggested for age at weaning but fewer CON-NG farmers weaned calves at ≥5 wk of age compared with ORG and CON-GR farmers. Only 23% of farms met program requirements for use of pain relief during dehorning, and fewer CON-NG farmers used pain relief for calves after dehorning compared with ORG and CON-GR farmers. Calves on ORG farms were fed a greater volume of milk and were weaned at an older age than calves on CON-GR and CON-NG farms. Calves on CON-GR farms were dehorned at a younger age compared with calves on ORG and CON-NG farms. The calving area was shared with lactating cows for a larger proportion of ORG herds compared with conventional herds. About 30% of herds met welfare program criteria for body condition score but only about 20% met criteria for animal hygiene scores. The least proportion of cows with hock lesions was observed on ORG farms. Regular use of veterinarians was infrequent for ORG herds. Results of this study indicate that most of the organic and conventional farms enrolled in this study would have been unlikely to achieve many criteria of audit and assessment programs currently used in the US dairy industry. PMID:24819133

  20. Creativity and Democratic Governance. Adult Learning: A Strategic Choice. Proceedings of the ICAE World Assembly (6th, Ocho Rios, Jamaica, August 9-12, 2001) = Creativite et Gouvernance Democratique. L'apprentissage des Adultes: Un Choix Strategique. Actes de la Assemblee Mondiale du CIEA (6th, Ocho Rios, Jamaique, 9 au 12 aout 2001) = Creatividad y Gobernabilidad Democratica. Educacion de Adultos: Una Eleccion Estrategica. Actas de la Asamblea Mundial del ICAE (6th, Ocho Rios, Jamaica, Agosto 9-12, 2001).

    ERIC Educational Resources Information Center

    Dobson, Stephan, Ed.

    This document contains information from and about a world assembly on creativity and democratic governance in adult learning that was held by the International Council for Adult Education (ICAE) and its partner organizations in the Caribbean. The proceedings begin with English, French, and Spanish translations of the address…

  1. 47 CFR 73.758 - System specifications for digitally modulated emissions in the HF broadcasting service.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) For digitally modulated emissions, the Digital Radio Mondiale (DRM) standard shall be employed. Both digital audio broadcasting and datacasting are authorized. The RF requirements for the DRM system are... require that the digital spectral power density (and total power) be lower by several dB than is...

  2. 47 CFR 73.758 - System specifications for digitally modulated emissions in the HF broadcasting service.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) For digitally modulated emissions, the Digital Radio Mondiale (DRM) standard shall be employed. Both digital audio broadcasting and datacasting are authorized. The RF requirements for the DRM system are... require that the digital spectral power density (and total power) be lower by several dB than is...

  3. 47 CFR 73.758 - System specifications for digitally modulated emissions in the HF broadcasting service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) For digitally modulated emissions, the Digital Radio Mondiale (DRM) standard shall be employed. Both digital audio broadcasting and datacasting are authorized. The RF requirements for the DRM system are... require that the digital spectral power density (and total power) be lower by several dB than is...

  4. The Computer and the Pre-School Child; The Written Language and Play.

    ERIC Educational Resources Information Center

    Naymark, J.; Plaisant, C.

    1986-01-01

    Describes a Centre Mondial Informatique et Resources Humaines (CIMRH) investigation of kindergarten children's written language learning and links between play and learning. Computer software was used by students for language learning, and observations centered on student computer use, learning of written language and play, and computer…

  5. Focusing Resources on Effective School Health: A FRESH Start to Enhancing the Quality and Equity of Education. World Education Forum 2000. Final Report = Accorder la priorite a un programme efficace de sante scolaire: Une maniere FRAICHE (FRESH) d'aneliorer la qualite et d'accroitre l'equite dans le domaine de l'education. Forum mondial 2000 sur l'education. Rapport final = Recursos efectivos en salud escolar: Un enfogue NUEVO para mejorar la calidad y la equidad educativa. Foro Mundial par la educacion 2000. Informe final.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    This booklet, written in English, Spanish, and French, describes the foundation and reasoning behind the partnership to Focus on Resources on Effective School Health (FRESH), making the case that an effective school health program: responds to the greater number of school-age children and the greater proportion of those children attending school;…

  6. Everest

    ScienceCinema

    None

    2011-04-25

    Chris Bonington, est né à Hampstead et a fait des études à University Collège School à Londres et au Royal Military Academy à Sundhorst. Il est un alpiniste mondialement connu qui a fait un grand nombre de premiers ascensions, comme celle de la face sud-ouest de l'Everest avec une équipe de 70 hommes en septembre 1975

  7. Geoffrey Burbidge : L'art de la critique

    NASA Astrophysics Data System (ADS)

    Bonnet-Bidaud, J. M.

    1997-06-01

    Avec pres de cinquante ans de carriere derriere lui, Geoffrey Burbidge n'a rien perdu de son gout du débat et de la controverse. Mondialement reconnu pour ses travaux sur les quasars, il en agace aujourd'hui plus d'un en venant deranger le bel ordonnancement de la cosmologie. Il porte sur le monde scientifique un regard tres critique, condamnant notamment ces chercheurs qui acceptent trop volontiers d'emprunter les chemins tout traces.

  8. Conference Salam/Musset

    ScienceCinema

    None

    2011-04-25

    Le DG L.Van Hove introduit le Prof. A.Salam né en 1926 dans l'ouest du Pakistan, un des gagnants du prix nobel de physique de cette année. Célébration de ses contributions théoriques mondialement connues. Après chaque discours, un petit historique est présenté par Paul Musset. Mention honorable aussi pour l'expérience Gargamelle et ses collaborateurs.

  9. Everest

    SciTech Connect

    2006-04-20

    Chris Bonington, est né à Hampstead et a fait des études à University Collège School à Londres et au Royal Military Academy à Sundhorst. Il est un alpiniste mondialement connu qui a fait un grand nombre de premiers ascensions, comme celle de la face sud-ouest de l'Everest avec une équipe de 70 hommes en septembre 1975

  10. 12 CFR Appendix F to Part 229 - Official Board Interpretations; Preemption Determinations

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... with § 229.20(d) of Regulation CC (12 CFR part 229), to determine whether the Expedited Funds... Board's Regulation D (12 CFR 204.2(d)). (Note, however, that under § 229.19(e) of Regulation CC, Holds...'s Regulation D (12 CFR 204.2(d)). (Note, however, that under § 229.19(e) of Regulation CC, Holds...

  11. 12 CFR Appendix F to Part 229 - Official Board Interpretations; Preemption Determinations

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... with § 229.20(d) of Regulation CC (12 CFR part 229), to determine whether the Expedited Funds... Board's Regulation D (12 CFR 204.2(d)). (Note, however, that under § 229.19(e) of Regulation CC, Holds...'s Regulation D (12 CFR 204.2(d)). (Note, however, that under § 229.19(e) of Regulation CC, Holds...

  12. 19-electron intermediates in the Ligand Substitution of CpW(CO)3with a Lewis Base

    SciTech Connect

    Cahoon, James F.; Kling, Matthias F.; Sawyer, Karma R.; Frei,Heinz; Harris, Charles B.

    2005-12-14

    Odd electron species are important intermediates in organometallic chemistry, participating in a variety of catalytic and electron-transfer reactions which produce stable even-electron products. While electron deficient 17-electron (17e) radicals have been well characterized, the possible existence of short-lived 19-electron (19e) radicals has been a subject of continuing investigation. 19e radicals have been postulated as intermediates in the photochemical ligand substitution and disproportionation reactions of organometallic dimers containing a single metal-metal bond, yet the reactions of these intermediates on diffusion-limited time scales (ns-{micro}s) have never been directly observed. This study resolves the 19e dynamics in the ligand substitution of 17e radicals CpW(CO){sub 3}{sup {sm_bullet}} (Cp = C{sub 5}H{sub 5}) with the Lewis base P(OMe){sub 3}, providing the first complete description 19e reactivity.

  13. 12 CFR Appendix F to Part 229 - Official Board Interpretations; Preemption Determinations

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... California Background The Board has been requested, in accordance with § 229.20(d) of Regulation CC (12 CFR... CFR 204.2(d)). (Note, however, that under § 229.19(e) of Regulation CC, Holds on other funds, the...'s Regulation D (12 CFR 204.2(d)). (Note, however, that under § 229.19(e) of Regulation CC, Holds...

  14. 12 CFR Appendix F to Part 229 - Official Board Interpretations; Preemption Determinations

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... California Background The Board has been requested, in accordance with § 229.20(d) of Regulation CC (12 CFR... CFR 204.2(d)). (Note, however, that under § 229.19(e) of Regulation CC, Holds on other funds, the...'s Regulation D (12 CFR 204.2(d)). (Note, however, that under § 229.19(e) of Regulation CC, Holds...

  15. 12 CFR Appendix F to Part 229 - Official Board Interpretations; Preemption Determinations

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... California Background The Board has been requested, in accordance with § 229.20(d) of Regulation CC (12 CFR... CFR 204.2(d)). (Note, however, that under § 229.19(e) of Regulation CC, Holds on other funds, the...'s Regulation D (12 CFR 204.2(d)). (Note, however, that under § 229.19(e) of Regulation CC, Holds...

  16. Forecasting landslide activations by means of GA-SAKe. An example of application to three case studies in Calabria (Southern Italy)

    NASA Astrophysics Data System (ADS)

    Iovine, Giulio G. R.; De Rango, Alessio; Gariano, Stefano L.; Terranova, Oreste G.

    2016-04-01

    Science and Practice, Margottini, Canuti, Sassa (Eds.), Vol. 3, pp.73-79. [2] Terranova O.G., Gariano S.L., Iaquinta P. & Iovine G.G.R. (2015). Geosci. Model Dev., 8, 1955-1978. [3] Iovine G., Iaquinta P. & Terranova O. (2009). In Anderssen, Braddock & Newham (Eds.), Proc. 18th World IMACS Congr. and MODSIM09 Int. Congr. on Modelling and Simulation, pp. 2686-2693. [4] Iovine G., Lollino P., Gariano S.L. & Terranova O.G. (2010). NHESS, 10, 2341-2354. [5] Capparelli G., Iaquinta P., Iovine G., Terranova O.G. & Versace P. (2012). Natural Hazards, 61(1), pp.247-256.

  17. Control of respiration in proteoliposomes containing cytochrome aa3. I. Stimulation by valinomycin and uncoupler.

    PubMed

    Hansen, F B; Miller, M; Nicholls, P

    1978-06-01

    1. Both valinomycin and p-trifluoromethoxy carbonyl cyanide phenylhydrazone (FCCP) are required for full release of respiration by cytochrome c oxidase-containing proteoliposomes (prepared by sonicating beef heart cytochrome aa3 in salt solution with 4 parts phosphatidylcholine, 4 parts phosphatidylethanolamine and 2 parts cardiolipin) in the presence of external ascorbate and cytochrome c. In the absence of valinomycin the response to FCCP is rather sluggish, as reported by Wrigglesworth et al. (1976) (Abstracts, 10th Int. Congr. Biochem., No. 06-6-230). 2. The Km for cytochrome c in 67 mM, pH 7.4, phosphate buffer with ascorbate as substrate, was 9 micrometer in both absence and presence of valinomycin and FCCP. Energization thus acts non-competitively towards cytochrome c oxidation. 3. The apparent Km for oxygen is greater in the energized than in the deenergized state; double reciprocal plots of respiration rate versus oxygen concentration are concave downward in the absence of uncouplers, as found with intact mitochondria. Energization thus acts "competitively" towards oxygen. 4. Despite the lack of a functional ATPase system, all the kinetic features of energization found in intact mitochondria can be mimicked in the reconstituted liposomes. This supports the chemiosmotic idea that electrical and perhaps H+ gradients modify the oxidase activity in reconstituted vesicles. PMID:207320

  18. Clinicopathological features of renal amyloidosis: a single-center study on 47 cases.

    PubMed

    Luo, Chang-qing; Zhang, Yu-an; Li, Zhen-qiong; Wang, Yu-mei

    2015-02-01

    The correlations between the clinicopathological features and the long-term outcomes of renal amyloidosis (RA) were analyzed with a view to develop strategies for improving diagnosis and prognosis of RA. We retrospectively reviewed the clinicopathological characteristics of 47 patients diagnosed with RA between 2004 and 2014 at the Wuhan Union Hospital. The data on the renal histology, clinical manifestations, and prognosis of RA patients were retrieved from the hospital records and characteristic patterns were identified. The histological changes in the kidneys were correlated with the clinical manifestations of RA. Additionally, most RA patients in this study had decreased serum levels of κ light chain and increased urine levels of κ and λ light chains as well as presence of M-protein in the urine and serum. Patients with early RA showed no specific pathognomonic symptoms. Bleeding associated with diagnostic renal biopsy was rare. We recommend that the routine work-up of patients aged over 40 years and presenting with non-diabetic nephropathy includes the non-invasive tests for the measurement of serum and urine levels of κ and λ light chains as well as protein electrophoresis tests for the presence of urinary and serum M-protein. Additionally, such patients should undergo renal biopsy screening with Cong-red staining to ensure early diagnosis of RA and improve their survival, since the risk of hemorrhage related to renal biopsy screening is low at early stages of RA. PMID:25673192

  19. [Congresses of the Croatian Medical Association regarding unpublished proceedings of the 10th congress in Zadar on September 25-28, 1996].

    PubMed

    Drazancić, Ante

    2011-01-01

    The first annual meeting of Croatian physicians, with characteristics of a congress, was held in 1899 at the 25th anniversary of the Croatian Medical Association. From 1954 to 1996, during almost 60 years of existence of the Croatian Medical Association, ten congresses of the Association were held. The congresses were during the development of modern medicine devoted to different medical questions, including some problems of national pathology, of the structure and restructuring of health care. The work and the content of congresses were published in the proceedings except for the 8th Congress in 1987 and the 10th in 1996. By reading main lectures, invited lectures and free papers the knowledge of that period can be gained. Many papers are even today actual, even today it could be learned from them. With more details, using published proceedings the 9th congress and the 10th congress are described on the basis preserved program, of a brief report in home journal and ample preserved correspondence. The national medical congres dedicated to technology advancement and to numerous problems of national pathology may be actual even today. They could help to solve many problems of health care, contribute to its improvement and convey consensus on its further development. PMID:22329299

  20. NIH deltanoids meeting on Vitamin D and cancer. Conclusion and strategic options.

    PubMed

    Bouillon, Roger; Moody, Terry; Sporn, Michael; Barrett, J Carl; Norman, Anthony W

    2005-10-01

    A meeting on "Cancer Chemoprevention and Cancer Treatment; role of vitamin D, 1alpha,25-(OH)(2)D(3) and deltanoids" was held on the NIH Congres, Bethesda in November 2004. The following conclusions were presented at the end of this symposium. Vitamin D deficiency and insufficiency are worldwide problems and are associated with several health problems including higher cancer prevalence. There is convincing evidence that the active vitamin D hormone, 1alpha,25(OH)(2)D(3), can decrease cell proliferation, modify cell apoptosis and control malignant cell growth. Therefore academia, public funding agencies and industry should urgently design appropriate studies to better define the causal relationship between vitamin D nutrition and cancer, define the optimal vitamin D nutrition based on accurate 25(OH)D measurement and inform the public and medical profession accordingly. Selective vitamin D receptor modulators are a potentially interesting new class of chemopreventive and chemotherapeutic agents as demonstrated by several first generation analogs have provided a convincing proof of concept. In the mean time, the public should be informed about the risks of vitamin D deficiency and insufficiency and appropriate steps should be taken to improve the vitamin D nutritional status of large parts of the world population. PMID:16043351

  1. Origin of the ultra-high-energy cosmic rays

    SciTech Connect

    Schramm, D.N.; Hill, C.T.

    1983-04-01

    The nature of the cosmic-ray spectrum above 10/sup 19/ eV discriminates between possible primary source models in a limited way. The shape of the spectrum, apart from normalization, is universal after a few photomeson interaction lengths. Fundamental processes, those sensitive to physics at e.g. the grand unification scale, are energy efficient and may be necessary to account for the normalization of the spectrum at the GZ cut-off. Very distant cosmological sources of this kind can generate significant structure above 10/sup 19/ eV. Local sources are not required and may even be problematic.

  2. Effect of three apple rootstocks on the population of the small red-belted clearwing borer, Synanthedon myopaeformis.

    PubMed

    Ateyyat, Mazen A

    2006-01-01

    Abstract Experiments were conducted in Ash-Shoubak area of Jordan from June 2003 to September 2005 to study the effect of three apple rootstocks on the development of the small red-belted clearwing borer, Synanthedon myopaeformis (Borkh.) (Lepidoptera: Sesiidae), under field conditions. Mondial Gala apple trees grafted on the dwarfing rootstock M9 and the semi-dwarfing rootstock M26 were equally infested, whereas those grafted on MM106 showed significantly lower infestation levels. S. myopaeformis bore into burr knots that develop below a graft union on rootstocks and girdle the tree. There was a significant effect of rootstock on the numbers of burrs present, and the percentage of burr knots infested by S. myopaeformis, with M106 having significantly fewer burrs, and a lower percent infested. PMID:20233078

  3. Male breast cancer: is the scenario changing

    PubMed Central

    Contractor, Kaiyumars B; Kaur, Kanchan; Rodrigues, Gabriel S; Kulkarni, Dhananjay M; Singhal, Hemant

    2008-01-01

    Background The overall incidence of male breast cancer is around 1% of all breast cancers and is on the rise. In this review we aim to present various aspects of male breast cancer with particular emphasis on incidence, risk factors, patho-physiology, treatment, prognostic factors, and outcome. Methods Information on all aspects of male breast cancer was gathered from available relevant literature on male breast cancer from the MEDLINE database over the past 32 years from 1975 to 2007. Various reported studies were scrutinized for emerging evidence. Incidence data were also obtained from the IARC, Cancer Mondial database. Conclusion There is a scenario of rising incidence, particularly in urban US, Canada and UK. Even though more data on risk factors is emerging about this disease, more multi-institutional efforts to pool data with large randomized trials to show treatment and survival benefits are needed to support the existing vast emerging knowledge about the disease. PMID:18558006

  4. Research on synchronization technique of the DRM system

    NASA Astrophysics Data System (ADS)

    Guo, Wen-fei; Zheng, Jian-sheng; Cheng, Wen; Su, Fan

    2011-10-01

    To deal with the degradation of the synchronization performance in low SNR condition, a novel DRM (Digital Radio Mondiale) synchronization algorithm is proposed. The proposed algorithm employs cyclic prefix for timing synchronization and fractional frequency offset estimation like conventional methods, but accomplishes frame synchronization and integer frequency offset estimation using time pilot cells and differential coding technologies, which are designed specially for the DRM system. After channel estimation and equalization, frequency pilot cells are used to estimate residue fractional frequency offset and subsequent sample offset as well as fixed phase offset to achieve complete synchronization. Simulation results show that the proposed algorithm can possesses better time and frequency synchronization performance than the conventional method in the multi-path fading channel with low SNR condition.

  5. Les vies de Galilée

    SciTech Connect

    2009-11-26

    Qu'est-ce que l'astronomie? A quoi sert-elle ? Qui était Galilée ? Une soirée avec Fiami, auteur et dessinateur autour des vies de Galilée, titre de son nouvel ouvrage. Galilée y joue le protagoniste ou le complice de grandes découvertes à différentes époques et sous divers profils : Galilée à Babylone (-568) | Galilée à Alexandrie (-197) | Galilée en Inde (499) | Galilée à Venise (1609) | Galilée et Halley (1705) | Galilée revient (2009) Dans le cadre de l'année mondiale de l'astronomie. » Tout public » Entrée libre » Réservation groupes au +41 (0)22 767 76 76

  6. Les vies de Galilée

    ScienceCinema

    None

    2011-10-06

    Qu'est-ce que l'astronomie? A quoi sert-elle ? Qui était Galilée ? Une soirée avec Fiami, auteur et dessinateur autour des vies de Galilée, titre de son nouvel ouvrage. Galilée y joue le protagoniste ou le complice de grandes découvertes à différentes époques et sous divers profils : Galilée à Babylone (-568) | Galilée à Alexandrie (-197) | Galilée en Inde (499) | Galilée à Venise (1609) | Galilée et Halley (1705) | Galilée revient (2009) Dans le cadre de l'année mondiale de l'astronomie. » Tout public » Entrée libre » Réservation groupes au +41 (0)22 767 76 76

  7. Grossesses extra utérines successives et bilharziose tubaire chez une touriste française

    PubMed Central

    Laroche, Justine; Mottet, Nicolas; Malincenco, Marianna; Gay, Catherine; Royer, Pierre Yves; Riethmuller, Didier

    2016-01-01

    La bilharziose est la seconde endémie parasitaire mondiale et ses atteintes génito urinaires sont bien décrites. Les grossesses ectopiques (GEU) sur obstruction tubaire par les œufs de bilharziose sont rapportées dans les populations africaines. La bilharziose affecte aussi les voyageurs mais l'atteinte de l'appareil génital féminin est plus rare. Nous rapportons un cas exceptionnel de deux GEU successives sur bilharziose tubaire chez une patiente d'origine Française, sept ans après un voyage touristique au Mali, la première découverte sur pièce de salpingectomie et la seconde ayant nécessité une salpingotomie controlatérale avec une injection de méthotrexate, deux mois plus tard. PMID:27200124

  8. 32 CFR 56.7 - Programs and activities subject to this part.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 5720.19E, “Navy Science Cruiser Program,” February 24, 1977. (5) Title 10 U.S. Code, section 9441 (1976... Army Corps of Engineers to State and local governments for the control of aquatic plant growths...

  9. 46 CFR 515.42 - Forwarder and carrier; compensation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... section 19(e)(4) of the Act (46 U.S.C. 40904(d)) and 46 CFR part 535. (e) Electronic data interchange. A....42 Shipping FEDERAL MARITIME COMMISSION REGULATIONS AFFECTING OCEAN SHIPPING IN FOREIGN COMMERCE LICENSING, FINANCIAL RESPONSIBILITY REQUIREMENTS, AND GENERAL DUTIES FOR OCEAN TRANSPORTATION...

  10. 46 CFR 515.42 - Forwarder and carrier; compensation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... section 19(e)(4) of the Act (46 U.S.C. 40904(d)) and 46 CFR part 535. (e) Electronic data interchange. A....42 Shipping FEDERAL MARITIME COMMISSION REGULATIONS AFFECTING OCEAN SHIPPING IN FOREIGN COMMERCE LICENSING, FINANCIAL RESPONSIBILITY REQUIREMENTS, AND GENERAL DUTIES FOR OCEAN TRANSPORTATION...

  11. 46 CFR 515.42 - Forwarder and carrier; compensation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... section 19(e)(4) of the Act (46 U.S.C. 40904(d)) and 46 CFR part 535. (e) Electronic data interchange. A....42 Shipping FEDERAL MARITIME COMMISSION REGULATIONS AFFECTING OCEAN SHIPPING IN FOREIGN COMMERCE LICENSING, FINANCIAL RESPONSIBILITY REQUIREMENTS, AND GENERAL DUTIES FOR OCEAN TRANSPORTATION...

  12. 32 CFR 56.7 - Programs and activities subject to this part.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 5720.19E, “Navy Science Cruiser Program,” February 24, 1977. (5) Title 10 U.S. Code, section 9441 (1976... Army Corps of Engineers to State and local governments for the control of aquatic plant growths...

  13. 24 CFR 882.803 - Project eligibility and other requirements.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... receiving Federal funding for rental assistance or operating costs under other HUD programs. (3) Nursing homes and related facilities such as intermediate care or board and care homes; units within the grounds.... 3601-19), E.O. 11063 (as amended by E.O. 12259; 3 CFR, 1959-1963 Comp., p. 652 and 3 CFR, 1980 Comp.,...

  14. 24 CFR 882.803 - Project eligibility and other requirements.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... receiving Federal funding for rental assistance or operating costs under other HUD programs. (3) Nursing homes and related facilities such as intermediate care or board and care homes; units within the grounds.... 3601-19), E.O. 11063 (as amended by E.O. 12259; 3 CFR, 1959-1963 Comp., p. 652 and 3 CFR, 1980 Comp.,...

  15. Search for ultra-high energy photons using Telescope Array surface detector

    SciTech Connect

    Rubtsov, G. I.; Troitsky, S. V.; Ivanov, D.; Stokes, B. T.; Thomson, G. B.

    2011-09-22

    We search for ultra-high energy photons by analyzing geometrical properties of shower fronts of events registered by the Telescope Array surface detector. By making use of an event-by-event statistical method, we derive an upper limit on the absolute flux of primary photons with energies above 10{sup 19} eV.

  16. On the Possibility of Radar Detection of Ultra-high Energy Cosmic Ray- and Neutrino-induced Air Showers

    NASA Technical Reports Server (NTRS)

    Gorham, P.

    1999-01-01

    We show that cosmic rays air showers resulting from primaries with energies above 10(sup 19) eV should be straightforward to detect with radar ranging techniques, where the radar echoes are produced by scattering from the column of ionized air produced by the shower.

  17. 24 CFR 882.803 - Project eligibility and other requirements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... providing continual psychiatric, medical, or nursing services are not eligible for assistance under this.... 3601-19), E.O. 11063 (as amended by E.O. 12259; 3 CFR, 1959-1963 Comp., p. 652 and 3 CFR, 1980 Comp., p... receiving Federal funding for rental assistance or operating costs under other HUD programs. (3)...

  18. A strategy to minimize reactive metabolite formation: discovery of (S)-4-(1-cyclopropyl-2-methoxyethyl)-6-[6-(difluoromethoxy)-2,5-dimethylpyridin-3-ylamino]-5-oxo-4,5-dihydropyrazine-2-carbonitrile as a potent, orally bioavailable corticotropin-releasing factor-1 receptor antagonist.

    PubMed

    Hartz, Richard A; Ahuja, Vijay T; Zhuo, Xiaoliang; Mattson, Ronald J; Denhart, Derek J; Deskus, Jeffrey A; Vrudhula, Vivekananda M; Pan, Senliang; Ditta, Jonathan L; Shu, Yue-Zhong; Grace, James E; Lentz, Kimberley A; Lelas, Snjezana; Li, Yu-Wen; Molski, Thaddeus F; Krishnananthan, Subramaniam; Wong, Henry; Qian-Cutrone, Jingfang; Schartman, Richard; Denton, Rex; Lodge, Nicholas J; Zaczek, Robert; Macor, John E; Bronson, Joanne J

    2009-12-10

    Detailed metabolic characterization of 8, an earlier lead pyrazinone-based corticotropin-releasing factor-1 (CRF(1)) receptor antagonist, revealed that this compound formed significant levels of reactive metabolites, as measured by in vivo and in vitro biotransformation studies. This was of particular concern due to the body of evidence suggesting that reactive metabolites may be involved in idiosyncratic drug reactions. Further optimization of the structure-activity relationships and in vivo properties of pyrazinone-based CRF(1) receptor antagonists and studies to assess the formation of reactive metabolites led to the discovery of 19e, a high affinity CRF(1) receptor antagonist (IC(50) = 0.86 nM) wherein GSH adducts were estimated to be only 0.1% of the total amount of drug-related material excreted through bile and urine, indicating low levels of reactive metabolite formation in vivo. A novel 6-(difluoromethoxy)-2,5-dimethylpyridin-3-amine group in 19e contributed to the potency and improved in vivo properties of this compound and related analogues. 19e had excellent pharmacokinetic properties in rats and dogs and showed efficacy in the defensive withdrawal model of anxiety in rats. The lowest efficacious dose was 1.8 mg/kg. The results of a two-week rat safety study with 19e indicated that this compound was well-tolerated. PMID:19954247

  19. Armor Procedural Skills: Learning and Retention. Technical Report 621.

    ERIC Educational Resources Information Center

    Knerr, C. Mazie; And Others

    Research investigated learning and retention of eight armor tasks selected to represent tasks varying in length, complexity, and extent of practice in operational units. Performance data were collected from soldiers in operational units and from soldiers attending One Station Unit Training (OSUT) in Armor Military Occupational Specialty (19E).…

  20. 76 FR 29784 - Notice of Realty Action; Direct Sale of Public Lands in Jerome County, ID

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-23

    ... owners of the adjacent private land, Todd and Bridget Buschhorn, for the appraised fair market value of... than the appraised fair market value: Boise Meridian T. 10 S., R. 19 E., sec. 25, lot 10. The area described contains 7.45 acres in Jerome County. The appraised fair market value is $5,600. The public...

  1. 46 CFR 515.42 - Forwarder and carrier; compensation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... section 19(e)(4) of the Act (46 U.S.C. 40904(d)) and 46 CFR part 535. (e) Electronic data interchange. A... of lading, dock receipt, or other similar document with respect to the shipment. (d) Compensation... interchange-based computer system in its forwarding business; however, the forwarder must directly...

  2. 12 CFR 509.1 - Scope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... denials of applications for case-by-case exemptions under 12 CFR part 585, which implements section 19(e... violation of: (1) Section 5 of the Home Owners' Loan Act (HOLA) or any regulation or order issued thereunder, pursuant to 12 U.S.C. 1464 (d), (s) and (v); (2) Section 9 of the HOLA or any regulation or order...

  3. 48 CFR 231.205-19 - Insurance and indemnification.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Insurance and... PROCEDURES Contracts With Commercial Organizations 231.205-19 Insurance and indemnification. (e) In addition to the cost limitations in FAR 31.205-19(e), self-insurance and purchased insurance costs are...

  4. 12 CFR 585.10 - What does this part do?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 6 2014-01-01 2012-01-01 true What does this part do? 585.10 Section 585.10 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY PROHIBITED SERVICE AT SAVINGS AND LOAN HOLDING COMPANIES § 585.10 What does this part do? This part implements section 19(e)(1)...

  5. 42 CFR 1007.20 - Circumstances in which data mining is permissible and approval by HHS Office of Inspector General.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Circumstances in which data mining is permissible... CONTROL UNITS § 1007.20 Circumstances in which data mining is permissible and approval by HHS Office of Inspector General. (a) Notwithstanding § 1007.19(e)(2), a MFCU may engage in data mining as defined in...

  6. 42 CFR 1007.20 - Circumstances in which data mining is permissible and approval by HHS Office of Inspector General.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Circumstances in which data mining is permissible... CONTROL UNITS § 1007.20 Circumstances in which data mining is permissible and approval by HHS Office of Inspector General. (a) Notwithstanding § 1007.19(e)(2), a MFCU may engage in data mining as defined in...

  7. 12 CFR 509.1 - Scope.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... denials of applications for case-by-case exemptions under 12 CFR part 585, which implements section 19(e... violation of: (1) Section 5 of the Home Owners' Loan Act (HOLA) or any regulation or order issued thereunder, pursuant to 12 U.S.C. 1464 (d), (s) and (v); (2) Section 9 of the HOLA or any regulation or order...

  8. 12 CFR 509.1 - Scope.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... denials of applications for case-by-case exemptions under 12 CFR part 585, which implements section 19(e... violation of: (1) Section 5 of the Home Owners' Loan Act (HOLA) or any regulation or order issued thereunder, pursuant to 12 U.S.C. 1464 (d), (s) and (v); (2) Section 9 of the HOLA or any regulation or order...

  9. 12 CFR 509.1 - Scope.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... denials of applications for case-by-case exemptions under 12 CFR part 585, which implements section 19(e... violation of: (1) Section 5 of the Home Owners' Loan Act (HOLA) or any regulation or order issued thereunder, pursuant to 12 U.S.C. 1464 (d), (s) and (v); (2) Section 9 of the HOLA or any regulation or order...

  10. 12 CFR 509.1 - Scope.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... denials of applications for case-by-case exemptions under 12 CFR part 585, which implements section 19(e... violation of: (1) Section 5 of the Home Owners' Loan Act (HOLA) or any regulation or order issued thereunder, pursuant to 12 U.S.C. 1464 (d), (s) and (v); (2) Section 9 of the HOLA or any regulation or order...

  11. 24 CFR 886.110 - Contract rents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... approved rent level established pursuant to 24 CFR 207.19(e)(2)(i). (c) In any case, HUD shall determine... the rents paid for comparable units in the private unassisted market, nor shall the Contract Rents exceed the rents charged by the Owner to unassisted Families for comparable units. HUD shall maintain...

  12. 24 CFR 886.110 - Contract rents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... approved rent level established pursuant to 24 CFR 207.19(e)(2)(i). (c) In any case, HUD shall determine... the rents paid for comparable units in the private unassisted market, nor shall the Contract Rents exceed the rents charged by the Owner to unassisted Families for comparable units. HUD shall maintain...

  13. 24 CFR 886.110 - Contract rents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... approved rent level established pursuant to 24 CFR 207.19(e)(2)(i). (c) In any case, HUD shall determine... the rents paid for comparable units in the private unassisted market, nor shall the Contract Rents exceed the rents charged by the Owner to unassisted Families for comparable units. HUD shall maintain...

  14. 24 CFR 886.110 - Contract rents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... approved rent level established pursuant to 24 CFR 207.19(e)(2)(i). (c) In any case, HUD shall determine... the rents paid for comparable units in the private unassisted market, nor shall the Contract Rents exceed the rents charged by the Owner to unassisted Families for comparable units. HUD shall maintain...

  15. 24 CFR 886.110 - Contract rents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... approved rent level established pursuant to 24 CFR 207.19(e)(2)(i). (c) In any case, HUD shall determine... the rents paid for comparable units in the private unassisted market, nor shall the Contract Rents exceed the rents charged by the Owner to unassisted Families for comparable units. HUD shall maintain...

  16. Identification and Characterization of an Immunogenic Hybrid Epitope Formed by both HIV gp120 and Human CD4 Proteins ▿

    PubMed Central

    Lewis, George K.; Fouts, Timothy R.; Ibrahim, Sani; Taylor, Brian M.; Salkar, Rachita; Guan, Yongjun; Kamin-Lewis, Roberta; DeVico, Anthony L.

    2011-01-01

    Certain antibodies from HIV-infected humans bind conserved transition state (CD4 induced [CD4i]) domains on the HIV envelope glycoprotein, gp120, and demonstrate extreme dependence on the formation of a gp120-human CD4 receptor complex. The epitopes recognized by these antibodies remain undefined although recent crystallographic studies of the anti-CD4i monoclonal antibody (MAb) 21c suggest that contacts with CD4 as well as gp120 might occur. Here, we explore the possibility of hybrid epitopes that demand the collaboration of both gp120 and CD4 residues to enable antibody reactivity. Analyses with a panel of human anti-CD4i MAbs and gp120-CD4 antigens with specific mutations in predicted binding domains revealed one putative hybrid epitope, defined by the human anti-CD4i MAb 19e. In virological and immunological tests, MAb 19e did not bind native or constrained gp120 except in the presence of CD4. This contrasted with other anti-CD4i MAbs, including MAb 21c, which bound unliganded, full-length gp120 held in a constrained conformation. Conversely, MAb 19e exhibited no specific reactivity with free human CD4. Computational modeling of MAb 19e interactions with gp120-CD4 complexes suggested a distinct binding profile involving antibody heavy chain interactions with CD4 and light chain interactions with gp120. In accordance, targeted mutations in CD4 based on this model specifically reduced MAb 19e interactions with stable gp120-CD4 complexes that retained reactivity with other anti-CD4i MAbs. These data represent a rare instance of an antibody response that is specific to a pathogen-host cell protein interaction and underscore the diversity of immunogenic CD4i epitope structures that exist during natural infection. PMID:21994452

  17. Monitoring and modelling for landslide risk mitigation and reduction. The case study of San Benedetto Ullano (Northern Calabria - Italy)

    NASA Astrophysics Data System (ADS)

    Terranova, Oreste G.; Greco, Venanzio R.; Gariano, Stefano L.; Pascale, Stefania; Rago, Valeria; Caloiero, Paola; Iovine, Giulio G. R.

    2016-04-01

    movements caused severe damage to roads and infrastructure. The second crisis ended up in late June: the hydrological model FLaIR was then successfully tested against the known dates of activation of the slope movement, by using a local rain series [3]. Meanwhile, technical support was being assured to the Municipality to optimize geological prospections, monitoring, and design of remedial works of a master plan. A third activation occurred during the night of 15 March 2013, when planned remedial works had not been completed yet. By applying the hydrological model SAKe [4, 5], this activation could be predicted, again permitting the prompt adoption of mitigation measures. Such activation was triggered by rains smaller and shorter than those that caused previous activations, perhaps indicating an apparent increasing fragility of the slope. Changes in slope stability conditions before and after the construction of the remedial works are being investigated. Critical rain conditions and groundwater levels for landslide activation are in fact expected to change, depending on combined effects of natural weakening vs. artificial strengthening. Monitoring will allow to quantitatively verify the new relationships between rainfall, groundwater and slope stability. References [1] Iovine G., Iaquinta P. & Terranova O. (2009). In Anderssen, Braddock & Newham (Eds.), Proc. 18th World IMACS Congr. and MODSIM09 Int. Congr. on Modelling and Simulation, pp. 2686-2693. [2] Iovine G., Lollino P., Gariano S.L. & Terranova O.G. (2010). NHESS, 10, 2341-2354. [3] Capparelli G., Iaquinta P., Iovine G., Terranova O.G. & Versace P. (2012). Natural Hazards, 61(1), pp.247-256. [4] Terranova O.G., Iaquinta P., Gariano S.L., Greco R. & Iovine G. (2013) In: Landslide Science and Practice, Margottini, Canuti, Sassa (Eds.), Vol. 3, pp.73-79. [5] Terranova O.G., Gariano S.L., Iaquinta P. & Iovine G.G.R. (2015). Geosci. Model Dev., 8, 1955-1978.

  18. The neutron channeling phenomenon.

    PubMed

    Khanouchi, A; Sabir, A; Boulkheir, M; Ichaoui, R; Ghassoun, J; Jehouani, A

    1997-01-01

    Shields, used for protection against radiation, are often pierced with vacuum channels for passing cables and other instruments for measurements. The neutron transmission through these shields is an unavoidable phenomenon. In this work we study and discuss the effect of channels on neutron transmission through shields. We consider an infinite homogeneous slab, with a fixed thickness (20 lambda, with lambda the mean free path of the neutron in the slab), which contains a vacuum channel. This slab is irradiated with an infinite source of neutrons on the left side and on the other side (right side) many detectors with windows equal to 2 lambda are placed in order to evaluate the neutron transmission probabilities (Khanouchi, A., Aboubekr, A., Ghassoun, J. and Jehouani, A. (1994) Rencontre Nationale des Jeunes Chercheurs en Physique. Casa Blanca Maroc; Khanouchi, A., Sabir, A., Ghassoun, J. and Jehouani, A. (1995) Premier Congré International des Intéractions Rayonnements Matière. Eljadida Maroc). The neutron history within the slab is simulated by the Monte Carlo method (Booth, T. E. and Hendricks, J. S. (1994) Nuclear Technology 5) and using the exponential biasing technique in order to improve the Monte Carlo calculation (Levitt, L. B. (1968) Nuclear Science and Engineering 31, 500-504; Jehouani, A., Ghassoun, J. and Aboubker, A. (1994) In Proceedings of the 6th International Symposium on Radiation Physics, Rabat, Morocco). Then different geometries of the vacuum channel have been studied. For each geometry we have determined the detector response and calculated the neutron transmission probability for different detector positions. This neutron transmission probability presents a peak for the detectors placed in front of the vacuum channel. This study allowed us to clearly identify the neutron channeling phenomenon. One application of our study is to detect vacuum defects in materials. PMID:9463884

  19. [Industrial first aid equipment: a historical analysis (1840-1914) ].

    PubMed

    Porro, Alessandro; Franchini, Antonia Francesca; Lorusso, Lorenzo; Falconi, Bruno

    2015-01-01

    Even if references to the tools required to intervene after an accident can be found in the works of Bernardino Ramazzini (1633-1714) or Johann Peter Frank (1745-1821), it was only with the development of industrial manufacturing that the need to study means to prevent and intervene in cases of accident became evident. In October 1894 the III Congrés International des Accidents du Travail et des Assurances Sociales was held in Milan. The following year, the Milanese trade union movement acknowledged the necessity to address the problem of industrial accidents. In 1896 the Association for Medical Assistance in  Industrial Accidents was founded in Milan. A specific medical institute was set up, appropriate first aid tools were collected and first aid rooms in the main Milanese factories were inaugurated. Nevertheless, few data seem to be available regarding the manufacture and use of this equipment in industry. We analyzed more than fifty catalogs of European industrial products, between 1843 and 1914, to study the evolution of first aid equipment for industrial use. They reflect and attest to the evolution of medicine and surgery, although some models seem to be related to certain industrial categories (railways, electrical appliances), some were similar to ordinary first aid boxes, others were strictly related to surgery; some could only be used by physicians, and others only by workers. Identification, conservation, and reappraisal of these tools is essential for historians of occupational health because these objects were normally not preserved. The catalogues of industrial production are also precious sources, since they are rarely preserved in public libraries and deserve to be used for historical studies. PMID:25607287

  20. The ESA Planetary Science Archive User Group (PSA-UG)

    NASA Astrophysics Data System (ADS)

    Pio Rossi, Angelo; Cecconi, Baptiste; Fraenz, Markus; Hagermann, Axel; Heather, David; Rosenblatt, Pascal; Svedhem, Hakan; Widemann, Thomas

    2014-05-01

    ESA has established a Planetary Science Archive User Group (PSA-UG), with the task of offering independent advice to ESA's Planetary Science Archive (e.g. Heather et al., 2013). The PSA-UG is an official and independent body that continuously evaluates services and tools provided by the PSA to the community of planetary data scientific users. The group has been tasked with the following top level objectives: a) Advise ESA on future development of the PSA. b) Act as a focus for the interests of the scientific community. c) Act as an advocate for the PSA. d) Monitor the PSA activities. Based on this, the PSA-UG will report through the official ESA channels. Disciplines and subjects represented by PSA-UG members include: Remote Sensing of both Atmosphere and Solid Surfaces, Magnetospheres, Plasmas, Radio Science and Auxilliary data. The composition of the group covers ESA missions populating the PSA both now and in the near future. The first members of the PSA-UG were selected in 2013 and will serve for 3 years, until 2016. The PSA-UG will address the community through workshops, conferences and the internet. Written recommendations will be made to the PSA coordinator, and an annual report on PSA and the PSA-UG activities will be sent to the Solar System Exploration Working Group (SSEWG). Any member of the community and planetary data user can get in touch with individual members of the PSA-UG or with the group as a whole via the contacts provided on the official PSA-UG web-page: http://archives.esac.esa.int/psa/psa-ug. The PSA is accessible via: http://archives.esac.esa.int/psa References: Heather, D., Barthelemy, M., Manaud, N., Martinez, S., Szumlas, M., Vazquez, J. L., Osuna, P. and the PSA Development Team (2013) ESA's Planetary Science Archive: Status, Activities and Plans. EuroPlanet Sci. Congr. #EPSC2013-626

  1. Social individualism: Walter Gropius and his appropriation of Franz Müller-Lyer's idea of a new man.

    PubMed

    Poppelreuter, Tanja

    2011-01-01

    In 1929, Walter Gropius developed the "High-Rise Steel Frame Apartment Building" that was based on theories about the emergence of a New Man put forward by sociologist Franz Müller-Lyer. In his lecture at the Congrès International d’Architecture Moderne conference in 1929, Gropius appropriated Müller-Lyer's sociology in order to promote and prompt the re-development of high-rise tenements and master households. Gropius’ 1931 contribution to the Deutsche Bauausstellung in Berlin incorporated a full-scale community lounge and a recreation area with sporting equipment, as well as a model and plans for a "High-Rise Steel Frame Apartment Building" that were designed in accordance with Müller-Lyer's theories. While it shows Müller-Lyer's influence, the boxing equipment found in the recreation area reflects the importance that sport, and boxing in particular, had gained after 1900. Boxing was perceived as a sport that would not only further fitness but also raise the spirits and help the inhabitant to succeed in the modern urban environment. By providing boxing equipment, Müller-Lyer's vision, which envisaged master households as furthering a community of peaceful individuals living in a condition of mutual trust, is weakened. In 1923, the sociologist Helmuth Plessner had regarded utopian visions of ideal communities as antithesis to actual events in the Weimar Republic. The embracing of theories that promised an evolutionary and linear development towards peaceful communities can be regarded as a counterreaction to a present that was perceived as an imperfect and temporary condition. Furthermore, Gropius’ appropriation of Müller-Lyer's sociology not only helped to distinguish his position from Marxist and socialist theories but also illustrated the contemporary tendency to accept utopian ideas while simultaneously doubting the practicality of some. PMID:21574288

  2. Improved limit on the muon electric dipole moment

    SciTech Connect

    Bennett, G. W.; Brown, H. N.; Bunce, G.; Danby, G. T.; Larsen, R.; Lee, Y. Y.; Meng, W.; Mi, J.; Morse, W. M.; Nikas, D.; Prigl, R.; Semertzidis, Y. K.; Warburton, D.; Bousquet, B.; Cushman, P.; Duong, L.; Giron, S.; Kindem, J.; Kronkvist, I.; Qian, T.

    2009-09-01

    Three independent searches for an electric dipole moment (EDM) of the positive and negative muons have been performed, using spin precession data from the muon g-2 storage ring at Brookhaven National Laboratory. Details on the experimental apparatus and the three analyses are presented. Since the individual results on the positive and negative muons, as well as the combined result, d{sub {mu}}=(0.0{+-}0.9)x10{sup -19}e cm, are all consistent with zero, we set a new muon EDM limit, |d{sub {mu}}|<1.8x10{sup -19}e cm (95% C.L.). This represents a factor of 5 improvement over the previous best limit on the muon EDM.

  3. A New Measurement of the Electric Dipole Moment of the Muon

    SciTech Connect

    Carey, Robert M.

    2009-12-17

    Three independent searches for an electric dipole moment (EDM) of the positive and negative muons have been performed, using spin precession data from the muon g-2 storage ring at Brookhaven National Laboratory. Brief details on the experimental apparatus and the three analyses are presented. Since the individual results on the positive and negative muon, as well as the combined result, d{sub {mu}} = (-0.1{+-}0.9)x10{sup -19} e{center_dot}cm, are all consistent with zero, we set a new muon EDM limit, |d{sub {mu}}|<1.9x10{sup -19} e{center_dot}cm(95% C.L.). This represents a factor of 5 improvement over the previous best limit on the muon EDM.

  4. Nuclear motion effects in the photoionisation of CO2

    SciTech Connect

    Swanson, J. R.; Dill, Dan; Dehmer, Joseph L.

    1980-04-14

    A calculation of the photoionization cross section of CO2 reveals that the σu shape resonance at approximately 19 eV, accessed by the 1πg and 4σg valence levels, is reduced and broadened by coupling to the ground-state vibrational motion. Off resonance the effect of nuclear motion is negligible. Results are compared with experimental branching ratios.

  5. Evolution of the ultra high energy cosmic ray spectrum by transport equation

    SciTech Connect

    Hill, C.T.; Schramm, D.N.

    1983-04-01

    Ultra-high energy proton primaries interacting with the 3/sup 0/K photon background are treated as a transport phenomenon. Baryon number is explicitly conserved and the evolved spectrum develops a bump at a scale of order 5x10/sup 19/ eV, below the cutoff, due to the pile-up of energy degraded protons. This may correspond in part to the observed ankle structure in the CR spectrum.

  6. 12 CFR 4.76 - Penalties.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10(k)(6) of the FDI Act (12 U.S.C. 1820(k)(6)) and in 12 CFR part 19. (e) Remedies not exclusive. The... under section 10(k) of FDI Act. If a senior examiner of a national bank, after leaving the employment of... with section 10(k)(6) of the FDI Act, be subject to one of the following penalties— (1) An order—...

  7. 12 CFR 4.76 - Penalties.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10(k)(6) of the FDI Act (12 U.S.C. 1820(k)(6)) and in 12 CFR part 19. (e) Remedies not exclusive. The... under section 10(k) of FDI Act. If a senior examiner of a national bank, after leaving the employment of... with section 10(k)(6) of the FDI Act, be subject to one of the following penalties— (1) An order—...

  8. Effects of pseudophosphorylation mutants on the structural dynamics of smooth muscle myosin regulatory light chain.

    PubMed

    Espinoza-Fonseca, L Michel; Colson, Brett A; Thomas, David D

    2014-10-01

    We have performed 50 independent molecular dynamics (MD) simulations to determine the effect of pseudophosphorylation mutants on the structural dynamics of smooth muscle myosin (SMM) regulatory light chain (RLC). We previously showed that the N-terminal phosphorylation domain of RLC simultaneously populates two structural states in equilibrium, closed and open, and that phosphorylation at S19 induces a modest shift toward the open state, which is sufficient to activate smooth muscle. However, it remains unknown why pseudophosphorylation mutants poorly mimic phosphorylation-induced activation of SMM. We performed MD simulations of unphosphorylated, phosphorylated, and three pseudophosphorylated RLC mutants: S19E, T18D/S19D and T18E/S19E. We found that the S19E mutation does not shift the equilibrium toward the open state, indicating that simple charge replacement at position S19 does not mimic the activating effect of phosphorylation, providing a structural explanation for previously published functional data. In contrast, mutants T18D/S19D and T18E/S19E shift the equilibrium toward the open structure and partially activate in vitro motility, further supporting the model that an increase in the mol fraction of the open state is coupled to SMM motility. Structural analyses of the doubly-charged pseudophosphorylation mutants suggest that alterations in an interdomain salt bridge between residues R4 and D100 results in impaired signal transmission from RLC to the catalytic domain of SMM, which explains the low ATPase activity of these mutants. Our results demonstrate that phosphorylation produces a unique structural balance in the RLC. These observations have important implications for our understanding of the structural aspects of activation and force potentiation in smooth and striated muscle. PMID:25091814

  9. Defect-related transitions in Zn3P2 studied by means of photovoltaic effect spectroscopy

    NASA Astrophysics Data System (ADS)

    Mirowska, N.; Misiewicz, J.

    1992-11-01

    Transitions at energies of 1.31 eV and 1.41 eV have been observed in Zn3P2 at room temperature (T=295 K) by using surface photovoltage (SPV) spectroscopy. Results obtained from absorption and photoconductivity measurements are also discussed here. The polarity of the PSV signal has been analysed. Two acceptor levels were found to be at 0.29 eV and 0.19 eV above the valence band.

  10. Risiophlebia guentheri sp. nov. (Odonata, Libellulidae) from southeastern Indochina.

    PubMed

    Kosterin, Oleg E

    2015-01-01

    Risiophlebia guentheri sp. nov. (holotype: Cambodia, Mondulkiri Province, Dak Dam village environs, a tall grass forest swamp, 12°25' N 107°19' E, ~780 m a.s.l., 16 June 2014, RMNH), the second species in its genus, is described from Central Plateau of the Annamese Mountains. The new species is most probably separated from R. dohrni by a 1000-km gap of the range of the genus in Thailand and most of Cambodia. PMID:26249427

  11. 47 CFR 90.721 - Other channels available for non-nationwide systems in the 220-222 MHz band.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Channel Nos. A EA 2 and 13 B EA 3 and 16 C EA 5 and 18 D EA 8 and 19 E EA 171-180 F REAG 1, 6, and 11 G...-nationwide systems in the 220-222 MHz band. (a) The channel groups listed in the following Table are... equivalent or greater efficiency for non-commercial or commercial operations. Table 1—Phase I Trunked...

  12. 47 CFR 90.721 - Other channels available for non-nationwide systems in the 220-222 MHz band.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Channel Nos. A EA 2 and 13 B EA 3 and 16 C EA 5 and 18 D EA 8 and 19 E EA 171-180 F REAG 1, 6, and 11 G...-nationwide systems in the 220-222 MHz band. (a) The channel groups listed in the following Table are... equivalent or greater efficiency for non-commercial or commercial operations. Table 1—Phase I Trunked...

  13. Plasma deposition of wide gap, highly photoconductive a-Si:H thin films from disilane-helium mixtures

    SciTech Connect

    Rajeswaran, G.; Vanier, P.E.; Corderman, R.R.; Kampas, F.J.

    1984-01-01

    Wide gap (>1.9 eV), photoconductive, intrinsic amorphous silicon films were made in a uhv system from Si/sub 2/H/sub 6/-He mixtures. The hydrogen concentrations, optical gaps and photoconductivities were measured. Unlike films made from SiH/sub 4/, Si/sub 2/H/sub 6/-produced films exhibit excellent electronic properties even at low deposition temperatures. The ratio of AM1 photoconductivity to dark conductivity was as high as 10/sup 7/.

  14. Determining the primary cosmic ray energy from the total flux of Cherenkov light measured at the Yakutsk EAS array

    SciTech Connect

    Ivanov, A. A. Knurenko, S. P.; Sleptsov, I. E.

    2007-06-15

    We present a method for determining the energy of the primary particle that generates an extensive air shower (EAS) of comic rays based on measuring the total flux of Cherenkov light from the shower. Applying this method to Cherenkov light measurements at the Yakutsk EAS array has allowed us to construct the cosmic ray energy spectrum in the range 10{sup 15} - 3 x 10{sup 19} eV.

  15. Padus, Sandalus, Gens Fadiena. Underwater Surveys in Palaeo-Watercourses (ferrara District - Italy)

    NASA Astrophysics Data System (ADS)

    Bucci, G.

    2015-04-01

    In the ambit of our program of researches on ancient rivers in Ferrara hinterland (Italy), we have been joining a Scientific - Didactic Project between Soprintendenza per i Beni Archeologici dell'Emilia Romagna, Comune di Portomaggiore Assessorato alla Cultura, CMAS A.CDCI. - Confédération Mondiale des Activités Subaquatiques Federation ITA F07 - Associazione CMAS Diving Center Italia. The Project is focused on underwater archaeological surveys in ex quarry lakes, following the Rivers Padus and Sandalus between Voghiera, Gambulaga and Portomaggiore (Ferrara District). Here we are going to introduce our most recent results, after the last immersions and a 3D bathymetrical survey completed by echo-side scan sonar in Tramonto Lake at Gambulaga, explaining the connection with remote sensing investigations and direct surveys applied to underwater archaeology of the inland water. The main submerged structure individuated is a part of wooden dock on the left side of Padus, in front of the Necropolis of Fadieni (1st-3rd cent. A.D.). Thanks to the study of 183 finds coming from the lake, involving students and young collaborators of the Archaeological National Museum of Ferrara, we are reconstructing the ancient landscape between Proto-Imperial Age and Late Antique.

  16. Highlights of recent progress in plant lipid research.

    PubMed

    Lessire, R; Cahoon, E; Chapman, K; Dyer, J; Eastmond, P; Heinz, E

    2009-06-01

    Raw fossil material reserves are not inexhaustible and as prices continue to raise it is necessary to find new sources of alternative and renewable energy. Oils from oleaginous field crops (sunflower and rape) with properties close to those of fossil fuel could constitute an alternative source of energy for the production of raw materials. This is the context in which the 18th International Symposium on Plant lipids (ISPL) was held in Bordeaux from 20th to 25th July 2008 at "La Cité Mondiale". The 18th ISPL gathered 270 researchers from 33 countries. Sixty nine oral communications and 136 posters were presented during the 12 sessions of the Symposium. The sessions have covered all the different aspects of the Plant Lipid field including: Surface lipids: suberin, cutin and waxes, Fatty acids, Glycerolipids, Plant lipids as renewable sources of energy, Seed oils and bioengineering of metabolic pathways, Lipid catabolism, Models for lipid studies: lower plants, micro-organisms and others, Modifications of proteins by lipids, Sphingolipids, sterols and isoprenoids, Lipid signaling and plant stress responses, Lipid trafficking and membrane dynamics, New methods and technologies: functional lipidomics, fluxome, modelling. During the ISPL 2008 Bordeaux, important and new information was reported in the different fields. A selection of these results is presented here. PMID:19328004

  17. Cancer métaplasique du sein: à propos d'un cas

    PubMed Central

    Babahabib, Moulay Abdellah; Chennana, Adil; Hachi, Aymen; Kouach, Jaoud; Moussaoui, Driss; Dhayni, Mohammed

    2014-01-01

    Les carcinomes métaplasiques du sein sont des tumeurs rares. Ils constituent un groupe hétérogène de tumeurs définis selon l'organisation mondiale de la santé comme étant un carcinome canalaire infiltrant mais comportant des zones de remaniements métaplasiques (de type épidermoïde, à cellules fusiformes, chondroïde et osseux ou mixte), qui varient de quelques foyers microscopiques à un remplacement glandulaire complet. Les aspects cliniques et radiologiques ne sont pas spécifiques. Le traitement associe la chirurgie, la radiothérapie et la chimiothérapie. L'hormonothérapie n'a pas de place. Le pronostic est sombre. L'histopathologie combinée à l'immunohistochimie permet de poser un diagnostic sure. Etant donné que la prise en charge thérapeutique est limitée, une nouvelle approche moléculaire pourrait modifier cette contribution faible et mal cernée des traitements systémiques classiques. Les patientes atteintes de carcinome métaplasique mammaire pourraient bénéficier de traitements ciblés, ce qui reste à confirmer par des essais cliniques. PMID:25870723

  18. [Screening in open angle glaucoma].

    PubMed

    Mocanu, Carmen; Mocanu, Andrei

    2012-01-01

    Primary open angle glaucoma (POAG) represents the second cause of mondial cecity, after retinal diabetes complications, with extremely severe implications in quality of life. Screening testing for glaucoma is justified, because only the diagnosis in very incipient stage will preserve the visual function; any treatment will not assure the reversibility of pre-existent optic nerve lesions. Screening of glaucoma, will take into a consideration the costs, the time of investigation, the adverse effects, and the sensitivity and specificity of tests; the last parameter also will strongly influence the positive predictive value. An ideal screening identifies all subjects that present the disease (sensitivity) and will exclude all healthy subjects (specificity). In this moment, in Dolj district, the diagnosis is based on active diagnosis of new cases of glaucoma on the high risk level population, therefore in a 210000 habitants. 4723 patients with glaucoma are diagnosed, screened and follow-up on medical cabinets and on Center of Glaucoma, which coordinates their activity. To better monitored patients, automatized programs with acquisition and storage for different types of medical imaging facilities had become indispensable to any routine practice. PMID:23755511

  19. Traitement intra-artériel des métastases hépatiques de cancer colorectal

    PubMed Central

    Pellerin, O.; Geschwind, J.-F.

    2015-01-01

    Le cancer colorectal représente un problème majeur de santé publique. Son incidence annuelle mondiale est d’environ un million de cas et la mortalité annuelle est de plus de 500 000 cas par an. Le foie est l’organe le plus fréquemment touché par les métastases. Leur survenue est observée dans 40 à 60% des cas (contemporaines dans 25% des cas). Bien que la résection chirurgicale soit le seul traitement curatif, nombre de patients ne peuvent en bénéficier en raison de l’importante diffusion des métastases hépatiques. Chimiothérapies et biothérapies systémiques sont les options conventionnelles de la prise en charge des métastases hépatiques multiples. C’est dans ces situations cliniques que les thérapies intra-artérielles peuvent jouer un rôle important. Dans cet article, nous présenterons les différentes thérapies endovasculaires applicables aux métastases hépatiques de cancers colorectaux, avec leurs indications, résultats et complications éventuelles. PMID:21944243

  20. Liquid Water vs. Hydrogen Cyanide on Enceladus

    NASA Astrophysics Data System (ADS)

    Glein, C. R.; Zolotov, M. Y.; Shock, E. L.

    2008-12-01

    The Ion and Neutral Mass Spectrometer onboard the Cassini spacecraft detected hydrogen cyanide (HCN) in plumes on Enceladus [1]. We explored computationally the thermodynamic stability and kinetic reactivity of HCN. Thermochemical equilibrium calculations show that HCN is unstable in liquid water, and should be overwhelmingly hydrolyzed to formic acid (HCOOH) and ammonia (NH3) under all conditions relevant to Enceladus. Even in an aqueous solution with an unreasonably high NH3 activity of 10, the HCOOH/HCN activity ratio is predicted to be greater than 107 at 0°C. This ratio decreases with increasing NH3 activity and with increasing temperature. Even at high temperatures (e.g., 200°C), it is at least 3-4 orders-of-magnitude above unity. It is notable that neither formic acid nor ammonia have been detected in any plumes [1]. We thus infer that the detected HCN is unlikely to have equilibrated with an aqueous solution below Enceladus' surface. Chemical kinetic considerations indicate that the hydrolysis lifetime of HCN has a complex dependence on pH, and decreases with increasing temperature. We find that, even at the pH value most conducive to the survival of HCN (~5), HCN can persist for only about 5 Ma in liquid water at 0°C. Thus, the HCN in the plumes could not have come from a long-lasting ocean or sea, and probably came from a recent aqueous melt or some icy phase. A liquid source for the HCN would be more restrictive than an ice source. For example, an aqueous solution must have a pH between 4-6 for HCN to be preserved in it for at least ~1 Ma at 0°C. However, this pH restriction would be lifted if the HCN source were a very young pool (i.e., centuries-millennia old). On the other hand, it is expected that HCN could survive indefinitely in an icy matrix. The proposed HCN sources may be less favorable abodes for life than a long-lived aqueous reservoir. Reference: [1] Waite J.H. et al. (2008) Eur. Planet. Sci. Congr. 3, EPSC2008-A-00593.

  1. In situ rutile petrochronology: texture-related T, Paleoproterozoic inheritance and a Pan-African overprint in the oldest subduction-related eclogites, Usagaran Orogen, Tanzania

    NASA Astrophysics Data System (ADS)

    Moeller, A.; Kraus, K.; Herms, P.; Appel, P.; Raase, P.

    2014-12-01

    example of the potential of in-situ rutile petrochronology in complex, polymetamorphic rocks when meticulous attention is given to textural context. Möller et al., 1995, Geology, v. 23, p. 1067-1070. Collins et al., 2004, Earth Planet. Sci. Lett., v. 224, p. 175-192. Wendt et al., 1972, 24th Internat. Geol. Congr., Proc., p. 295-314.

  2. To be or not to be Yutsis: Algorithms for the decision problem

    NASA Astrophysics Data System (ADS)

    Van Dyck, D.; Brinkmann, G.; Fack, V.; McKay, B. D.

    2005-12-01

    Generalized recoupling coefficients or 3nj-coefficients can be expressed as multiple sums over products of Racah or 6 j-coefficients [L.C. Biedenharn, J.D. Louck, Coupling of n angular momenta: recoupling theory, in: The Racah-Wigner Algebra in Quantum Theory, Encyclopedia of Mathematics and its Applications, vol. 9, Addison-Wesley, 1981, pp. 435-481]. The problem of finding an optimal summation formula (i.e. with a minimal number of Racah coefficients) for a given 3nj-coefficient is equivalent to finding an optimal reduction of a so-called Yutsis graph [A.P. Yutsis, I.B. Levinson, V.V. Vanagas, Mathematical Apparatus of the Theory of Angular Momentum, Israel Program for Scientific Translation, Jerusalem, 1962]. In terms of graph theory Yutsis graphs are connected simple cubic graphs which can be partitioned into two vertex induced trees. The two parts are necessarily of the same size. In this area Yutsis graphs are also studied under the name of cubic dual Hamiltonian graphs [F. Jaeger, On vertex-induced forests in cubic graphs, in: Proc. 5th Southeastern Conference, Congr. Numer. (1974) 501-512]. We present algorithms for determining whether a cubic graph is a Yutsis graph. This is interesting for generating large test cases for programs (as in [P.M. Lima, Comput. Phys. Comm. 66 (1991) 89; S. Fritzsche, T. Inghoff, T. Bastug, M. Tomaselli, Comput. Phys. Comm. 139 (2001) 314; D. Van Dyck, V. Fack, GYutsis: heuristic based calculation of general recoupling coefficients, Comput. Phys. Comm. 154 (2003) 219-232]) that determine a summation formula for a 3nj-coefficient. Moreover, we give the numbers of Yutsis and non-Yutsis cubic graphs with up to 30 vertices and cubic polyhedra with up to 40 vertices. All these numbers have been computed by two independent programs in order to reduce the probability of error. Since the decision problem whether a given cubic graph is Yutsis or not is NP-complete, we could not hope for a polynomial time worst case performance of our

  3. PlanetServer/EarthServer: Big Data analytics in Planetary Science

    NASA Astrophysics Data System (ADS)

    Pio Rossi, Angelo; Oosthoek, Jelmer; Baumann, Peter; Beccati, Alan; Cantini, Federico; Misev, Dimitar; Orosei, Roberto; Flahaut, Jessica; Campalani, Piero; Unnithan, Vikram

    2014-05-01

    Planetary data are freely available on PDS/PSA archives and alike (e.g. Heather et al., 2013). Their exploitation by the community is somewhat limited by the variable availability of calibrated/higher level datasets. An additional complexity of these multi-experiment, multi-mission datasets is related to the heterogeneity of data themselves, rather than their volume. Orbital - so far - data are best suited for an inclusion in array databases (Baumann et al., 1994). Most lander- or rover-based remote sensing experiment (and possibly, in-situ as well) are suitable for similar approaches, although the complexity of coordinate reference systems (CRS) is higher in the latter case. PlanetServer, the Planetary Service of the EC FP7 e-infrastructure project EarthServer (http://earthserver.eu) is a state-of-art online data exploration and analysis system based on the Open Geospatial Consortium (OGC) standards for Mars orbital data. It provides access to topographic, panchromatic, multispectral and hyperspectral calibrated data. While its core focus has been on hyperspectral data analysis through the OGC Web Coverage Processing Service (Oosthoek et al., 2013; Rossi et al., 2013), the Service progressively expanded to host also sounding radar data (Cantini et al., this volume). Additionally, both single swath and mosaicked imagery and topographic data are being added to the Service, deriving from the HRSC experiment (e.g. Jaumann et al., 2007; Gwinner et al., 2009) The current Mars-centric focus can be extended to other planetary bodies and most components are general purpose ones, making possible its application to the Moon, Mercury or alike. The Planetary Service of EarthServer is accessible on http://www.planetserver.eu References: Baumann, P. (1994) VLDB J. 4 (3), 401-444, Special Issue on Spatial Database Systems. Cantini, F. et al. (2014) Geophys. Res. Abs., Vol. 16, #EGU2014-3784, this volume Heather, D., et al.(2013) EuroPlanet Sci. Congr. #EPSC2013-626 Gwinner, K

  4. Progress toward a 30 percent-efficient, monolithic, three-junction, two-terminal concentrator solar cell for space applications

    NASA Technical Reports Server (NTRS)

    Partain, L. D.; Chung, B.-C.; Virshup, G. F.; Schultz, J. C.; Macmillan, H. F.; Ristow, M. Ladle; Kuryla, M. S.; Bertness, K. A.

    1991-01-01

    Component efficiencies of 0.2/sq cm cells at approximately 100x AMO light concentration and 80 C temperatures are not at 15.3 percent for a 1.9 eV AlGaAs top cell, 9.9 percent for a 1.4 eV GaAs middle cell under a 1.9 eV AlGaAs filter, and 2.4 percent for a bottom 1.0 eV InGaAs cell under a GaAs substrate. The goal is to continue improvement in these performance levels and to sequentially grow these devices on a single substrate to give 30 percent efficient, monolithic, two-terminal, three-junction space concentrator cells. The broad objective is a 30 percent efficient monolithic two-terminal cell that can operate under 25 to 100x AMO light concentrations and at 75 to 100 C cell temperatures. Detailed modeling predicts that this requires three junctions. Two options are being pursued, and both use a 1.9 eV AlGaAs top junction and a 1.4 eV GaAs middle junction grown by a 1 atm OMVPE on a lattice matched substrate. Option 1 uses a low-doped GaAs substrate with a lattice mismatched 1.0 eV InGaAs cell formed on the back of the substrate. Option 2 uses a Ge substrate to which the AlGaAs and GaAs top junctions are lattice matched, with a bottom 0.7 eV Ge junction formed near the substrate interface with the GaAs growth. The projected efficiency contributions are near 16, 11, and 3 percent, respectively, from the top, middle, and bottom junctions.

  5. Reduced Perinatal Leptin Availability May Contribute to Adverse Metabolic Programming in a Rat Model of Uteroplacental Insufficiency.

    PubMed

    Nüsken, Eva; Wohlfarth, Maria; Lippach, Gregor; Rauh, Manfred; Schneider, Holm; Dötsch, Jörg; Nüsken, Kai-Dietrich

    2016-05-01

    Leptin availability in perinatal life critically affects metabolic programming. We tested the hypothesis that uteroplacental insufficiency and intrauterine stress affect perinatal leptin availability in rat offspring. Pregnant rats underwent bilateral uterine vessel ligation (LIG; n = 14), sham operation (SOP; n = 12), or no operation (controls, n = 14). Fetal livers (n = 180), placentas (n = 180), and maternal blood were obtained 4 hours (gestational day [E] 19), 24 hours (E20), and 72 hours (E22) after surgery. In the offspring, we took blood samples on E22 (n = 44), postnatal day (P) 1 (n = 29), P2 (n = 16), P7 (n = 30), and P12 (n = 30). Circulating leptin (ELISA) was significantly reduced in LIG (E22, P1, P2) and SOP offspring (E22). Postnatal leptin surge was delayed in LIG but was accelerated in SOP offspring. Placental leptin gene expression (quantitative RT-PCR) was reduced in LIG (E19, E20, E22) and SOP (E20, E22). Hepatic leptin receptor (Lepr-a, mediating leptin degradation) gene expression was increased in LIG fetuses (E20, E22) only. Surprisingly, hypoxia-inducible factors (Hif; Western blot) were unaltered in placentas and were reduced in the livers of LIG (Hif1a, E20; Hif2a, E19, E22) and SOP (Hif2a, E19) fetuses. Gene expression of prolyl hydroxylase 3, a factor expressed under hypoxic conditions contributing to Hif degradation, was increased in livers of LIG (E19, E20, E22) and SOP (E19) fetuses and in placentas of LIG and SOP (E19). In summary, reduced placental leptin production, increased fetal leptin degradation, and persistent perinatal hypoleptinemia are present in intrauterine growth restriction offspring, especially after uteroplacental insufficiency, and may contribute to perinatal programming of leptin resistance and adiposity in later life. PMID:27007072

  6. Isotropy Constraints on Powerful Sources of Ultrahigh-energy Cosmic Rays at 1019 eV

    NASA Astrophysics Data System (ADS)

    Takami, Hajime; Murase, Kohta; Dermer, Charles D.

    2016-01-01

    Anisotropy in the arrival direction distribution of ultrahigh-energy cosmic rays (UHECRs) produced by powerful sources is numerically evaluated. We show that nondetection of significant anisotropy at ≈ {10}19 eV at present and in future experiments imposes general upper limits on UHECR proton luminosity of steady sources as a function of source redshifts. The upper limits constrain the existence of typical steady {10}19 eV UHECR sources in the local universe and limit their local density to ≳ {10}-3 Mpc {}-3, assuming average intergalactic magnetic fields less than {10}-9 G. This isotropy, being stronger than that measured at the highest energies, may indicate the transient generation of UHECRs. Our calculations are applied for extreme high-frequency-peaked BL Lacertae objects 1ES 0229+200, 1ES 1101-232, and 1ES 0347-121, to test the UHECR-induced cascade model, in which beamed UHECR protons generate TeV radiation in transit from sources. While the magnetic-field structure surrounding the sources affects the required absolute cosmic-ray luminosity of the blazars, the magnetic-field structure surrounding the Milky Way directly affects the observed anisotropy. If these magnetic fields are weak enough, significant UHECR anisotropy from these blazars is detectable by the Pierre Auger Observatory unless the maximum energy of UHECR protons is below 1019 eV. Furthermore, if these are the sources of UHECRs above 1019 eV, a local magnetic structure surrounding the Milky Way is needed to explain the observed isotropy at ˜ {10}19 eV, which may be incompatible with large magnetic structures around all galaxies for the UHECR-induced cascade model to work with reasonable jet powers.

  7. Electronic structure and mass enhancement of the heavy fermion superconductor UPt 3

    NASA Astrophysics Data System (ADS)

    Wang, C. S.; Krakauer, H.; Pickett, W. E.

    1985-12-01

    The self-consistent general potential linearized augmented plane wave method has been applied to study the enegy bands of the heavy fermion superconductor UPt 3 within the local density approxination. We found 2.5 f-electrons per U atom and a f-band width of ≈1.9 eV pinned at the Fermi energy EF. An enhancement factor of 19 is deduced from the density of states at EF and the experimental linear coefficient of the specific heat. Possible sources of the renormalization are discussed based on available experimental information.

  8. Current Impact Risks

    Science.gov Websites

    0.211 -4.36 -4.40 0 2016 JR38 2086-2086 1 1.9e-09 2.10 25.5 0.027 -9.33 -9.33 0 2016 JP38 2020-2078 25 1.7e-08 9.77 24.4 0.044 -6.76 -7.09 0 2016 JO38 2016-2115 467 9.6e-07 7.41 ...

  9. Magnetic and electron spin resonance studies of (Ce 1-cGd c)Rh 2

    NASA Astrophysics Data System (ADS)

    Tari, A.

    1990-08-01

    Magnetic and ESR measurements have been performed on several samples of the (Ce 1-cGd c)Rh 2 series in the interval 0 ≦ c ≦ 1. It is found that only those Ce atoms with at least 3nn Gd atoms are magnetic. The cerium sublattice appears to reach the magnetic percolation limit at about c=0.3. Using the lattice parameters and the RKKY model a value of 0.19eV is computed for the effective exchange integral Jo at the GdRh 2 end of the series.

  10. Interpreting cosmic ray spectra and composition above 100 TeV

    SciTech Connect

    Gaisser, T.K.

    1995-07-10

    Cosmic radiation which have energies above 100 TeV are discussed. Exam of the possible sources of such high energy particles are given. Also, measurement of high energy muons in air showers as a probe of composition in the 10{sup 14} to 10{sup 17} eV region of the spectrum is discussed. Finally, a description of a simulation used to analyze the 10{sup 17} to 10{sup 19} eV energy region of the spectrum is given. In this higher energy region evidence for a transition to a new population of particles exists. (AIP) {copyright}{ital American} {ital Institute} {ital of} {ital Physics} 1995

  11. Nuclear magnetic resonance study of sulfate reorientations in LiNaSO4.

    PubMed

    Shakhovoy, R A; Rakhmatullin, A; Deschamps, M; Sarou-Kanian, V; Bessada, C

    2016-05-01

    A nuclear magnetic resonance study of the sulfate ion reorientations in β-LiNaSO4 has been carried out. The influence of the SO4 reorientational jumps on the quadrupolar interactions of (7)Li nuclei was investigated by a jump reorientational model, which has not previously been applied to sulfates. The activation energy required for the SO4 reorientations was found to be 0.19 eV. It was also revealed that the SO4 reorientational disorder should be associated with a small anomaly of a heat capacity at around 600 K, which was previously observed experimentally. PMID:27028697

  12. The cosmic ray spectrum above 10(17) eV

    NASA Technical Reports Server (NTRS)

    Winn, M. M.; Ulrichs, J.; Horton, L.; Mccusker, C. B. A.; Peak, L. S.

    1986-01-01

    The final analysis of the data obtained by the Sydney University Giant Airshower Recorder (SUGAR) is presented. The data has been reanalysed to take into account the effects of afterpulsing in the photomultiplier tubes. Event data was used to produce a spectrum of equivalent vertical muon number and from this a model dependent primary energy spectrum was obtained. These spectra show good evidence for the Ankle: a flattening at 10(19) eV. There is no sign of the cut-off which would be expected from the effects of the universal black body radiation.

  13. Photoinduced conductivity changes in polycrystalline diamond films

    NASA Astrophysics Data System (ADS)

    Gonon, P.; Prawer, S.; Jamieson, D.

    1996-02-01

    We report that the dark electrical properties of polycrystalline chemical vapor deposition diamond films are modified after exposure to UV light. UV illumination gives rise to an increase in the dark conductivity and to a change in the I-V characteristic from Iα exp (aV) for the as-grown material to IαV2 following UV irradiation. Thermally stimulated currents corresponding to an activation energy of about 1.9 eV are observed after UV illumination. The effects of UV irradiation can be totally reversed by thermal annealing and partially reversed by exposing the samples to white light.

  14. Note: Charge transfer in a hydrated peptide group is determined mainly by its intrinsic hydrogen-bond energetics

    SciTech Connect

    Mirkin, Noemi G.; Krimm, Samuel

    2014-01-28

    Charge transfer in a hydrogen-bonded N-methylacetamide(H{sub 2}O){sub 3} system is obtained from ωB97X-D/6-31++G** and CHelpG atomic charge calculations of individual peptide-water interactions as well as that of the entire complex. In the latter, the electron transfer to water is 0.19 e, influenced primarily by the hydrogen bonds to the C=O group. The values of such charge transfer are paralleled by the corresponding intrinsic hydrogen-bond energies. These results support the desirability of incorporating charge transfer in molecular mechanics energy functions.

  15. The muon EDM in the g-2 experiment at Fermilab

    NASA Astrophysics Data System (ADS)

    Chislett, Rebecca

    2016-04-01

    The observation of a muon electric dipole moment would provide an additional source of CP violation which is required to explain the matter anti-matter asymmetry in the universe. The current experimental limit, |dμ| < 1.9 × 10-19e·cm, was set by the BNL E821 experiment. This paper discusses how the new experiment at Fermilab, E989 [3], aims to decrease this by two orders of magnitude down to 10-21e·cm.

  16. Low Temperature Silicon Surface Cleaning by HF Etching/Ultraviolet Ozone Cleaning (HF/UVOC) Method (II)—in situ UVOC

    NASA Astrophysics Data System (ADS)

    Kaneko, Tetsuya; Suemitsu, Maki; Miyamoto, Nobuo

    1989-12-01

    A new method to obtain clean silicon surfaces using a thermal treatment at as low as 700°C is proposed. The method consists of an ex situ treatment of HF dipping followed by a rinse in distilled, deionized water and in situ treatments of both UVOC under low oxygen pressure and annealing in vacuo. From the Arrhenius plot of the removal rate of the surface oxide, two mechanisms corresponding to a diffusion of the volatile product, SiO, and a reaction between oxygen and silicon are suggested to exist, with activation energies 3.7 eV and 1.9 eV, respectively.

  17. Conformational features of secondary N-cyclopropyl amides.

    PubMed

    González-de-Castro, Ángela; Broughton, Howard; Martínez-Pérez, José A; Espinosa, Juan F

    2015-04-17

    NMR studies in conjunction with ab initio calculations revealed unexpected conformational behavior of N-cyclopropylacetamide (1). This secondary amide displays 16-19% E-rotamer (cis) around the carbonyl-nitrogen bond in apolar solvents, in contrast to other aliphatic secondary acetamides in which significant E-rotamer populations are rare due to steric contacts between the substituents on the amide bond. In addition, 1 adopts an ortho conformation around the N-cPr bond instead of the anti conformation generally preferred by secondary acetamides. This distinct conformational behavior was also observed for other secondary N-cyclopropyl amides. PMID:25803271

  18. Plasma deposition of wide gap, highly photoconductive a-Si:H thin films from disilane-helium mixtures

    SciTech Connect

    Rajeswaran, G.; Vanier, P.E.; Corderman, R.R.; Kampas, F.J.

    1985-01-01

    Wide gap (> 1.9 eV), photoconductive, intrinsic amorphous silicon films were made in a UHV system from Si/sub 2/H/sub 6/-He mixtures. The hydrogen concentrations, optical gaps and photoconductivities were measured. Unlike films made from SiH/sub 4/, Si/sub 2/H/sub 6/-produced films exhibit excellent electronic properties even at low deposition temperatures. The ratio of AM1 photoconductivity to dark conductivity was as high as 10/sup 7/. 17 references, 5 figures, 1 table.

  19. Second dip as a signature of ultrahigh energy proton interactions with cosmic microwave background radiation.

    PubMed

    Berezinsky, V; Gazizov, A; Kachelrieb, M

    2006-12-01

    We discuss as a new signature for the interaction of extragalactic ultrahigh energy protons with cosmic microwave background radiation a spectral feature located at E= 6.3 x 10(19) eV in the form of a narrow and shallow dip. It is produced by the interference of e+e(-)-pair and pion production. We show that this dip and, in particular, its position are almost model-independent. Its observation by future ultrahigh energy cosmic ray detectors may give the conclusive confirmation that an observed steepening of the spectrum is caused by the Greisen-Zatsepin-Kuzmin effect. PMID:17280191

  20. Influence of fluorine on the fiber resistance studied through the nonbridging oxygen hole center related luminescence

    SciTech Connect

    Vaccaro, L.; Cannas, M.; Alessi, A.; Boscaino, R.; Girard, S.; Boukenter, A.; Ouerdane, Y.; Morana, A.

    2013-05-21

    The distribution of Non-Bridging Oxygen Hole Centers (NBOHCs) in fluorine doped optical fibers was investigated by confocal microluminescence spectroscopy, monitoring their characteristic 1.9 eV luminescence band. The results show that these defects are generated by the fiber drawing and their concentration further increases after {gamma} irradiation. The NBOHC concentration profile along the fiber provides evidence for an exponential decay with the fluorine content. This finding agrees with the role of fluorine in the fiber resistance and is discussed, from the microscopic point of view, by looking at the conversion mechanisms from strained bonds acting as precursors.

  1. Pertinence de l'implantation de la filiere granule de bois pour le Quebec

    NASA Astrophysics Data System (ADS)

    Tremblay, Stephan

    Les spécialistes avancent que le marché mondial de l'énergie en forte demande et en offre limitée nécessitera bientôt toutes les formes d'énergie disponibles. Le granulé de bois est une forme de bioénergie principalement utilisée pour le chauffage des bâtiments et pourrait être davantage considéré dans l'offre énergétique du Québec. Comme le Québec est un territoire où il fait froid et donc susceptible de pouvoir se tourner vers cette forme d'énergie, l'objectif de ce mémoire est d'en analyser les avantages. Pour ce faire, nous commencerons par démontrer la croissance des besoins énergétiques sur les plans national et international et dresser un portrait des différentes formes d'énergies consommées au Québec. Puisque la majorité des Québécois chauffent leurs bâtiments à l'hydroélectricité, nous analyserons à travers le plan d'approvisionnement d'Hydro-Québec le portrait de la production et de la consommation de cette forme d'énergie renouvelable. Cela nous permettra de constater le défi face à la gestion de surplus importants, sauf pendant la période hivernale, et ce faisant, l'obligation de la société d'État d'utiliser davantage ses centrales au gaz ou de se tourner vers l'importation de l'électricité. Dans la même lignée, un regard sera porté sur les perspectives d'utilisation de l'hydroélectricité sur les plans de la production d'aluminium, de l'exportation et de l'utilisation dans l'électrification des transports au Québec. Cette analyse se fera dans l'objectif de s'interroger sur la pertinence d'utiliser cette source d'énergie dans le chauffage plutôt que dans des secteurs plus créateurs de richesse. Nous poserons ensuite l'hypothèse que le granulé de bois pourrait être un bon substitut à une autre forme d'énergie utilisée dans le chauffage, soit le mazout. Avant de dresser un portrait de ce combustible fossile, nous ferons celui de la production et de la consommation de granulés sur les plans r

  2. Facteurs de risque de mortalité par tuberculose pulmonaire

    PubMed Central

    Janah, Hicham; Souhi, Hicham; Kouismi, Hatim; Mark, Karima; Zahraoui, Rachida; Benamor, Jouda; Soualhi, Mona; Bourkadi, Jamal Eddine

    2014-01-01

    La tuberculose est une maladie infectieuse transmissible provoquée par myco-bacterium tuberculosis (bacille de Koch ou BK). Elle représente, selon les estimations del'Organisation Mondiale de la Santé (OMS), l'une des pathologies infectieuses causant le plus de décès au niveau mondial avec plus de 1 million de décès par an. Pour déterminer les facteurs de risque de mortalité au cours de la tuberculose pulmonaire à microscopie positive nous avons mené une étude rétrospective portant sur tous les cas de tuberculose pulmonaire à microscopie positive et qui étaient décédés au cours de leur hospitalisation. Cette étude a colligé 1803 cas de tuberculose sur une période de 2 ans et demi dont 46 sont décédés. La prévalence de décès est de 2,55%. La population se répartit en 32 hommes et 14 femmes. L’âge moyen était de 53ans ± 17 ans. Le tabagisme était retrouvé chez la moitié des cas. Une comorbidité était retrouvée dans 43%, avec 17% de diabète. Le délai de diagnostic avait une médiane de 60 jours avec percentile (30j; 105j). La symptomatologie clinique était dominée par la toux, la dyspnée et les expectorations soit respectivement: 97,8%, 69,6% et 67,4% des cas. Sur le plan radiologique les lésions étaient diffuses et bilatérales dans 76,1% des cas. Tous les patients étaient mis sous SRHZ. 11% avaient présenté une toxicité aux antibacillaires (de type hépatiques dans 3 cas et neurologiques dans 2 cas). Le délai médian de décès était de 8,5 jours (5j; 17j). Les causes de décès retrouvées étaient: Une hépatite fulminante (3 cas), une décompensation acido-cétosique (3 cas), un SDRA (2 cas), des hémoptysies foudroyantes (2 cas), et respectivement un cas secondaire à une décompensation de BPCO, une décompensation cardiaque, une hypoglycémie et un tableau d'anasarque. Cette étude suggère que le terrain, le retard diagnostique et les effets secondaires du traitement sont les principaux facteurs de risque de

  3. Comparison of PremierTM Rotaclone®, ProSpecTTM, and RIDASCREEN® Rotavirus Enzyme Immunoassay Kits for Detection of Rotavirus Antigen in Stool Specimens

    PubMed Central

    Gautam, Rashi; Lyde, Freda; Esona, Mathew D.; Quaye, Osbourne; Bowen, Michael D.

    2015-01-01

    Background Rotaviruses are the major cause of severe dehydrating diarrhea in children throughout the world. Enzyme immunoassays (EIA) have been the standard method for detection of rotavirus in stool specimens since the 1980s. The World Health Organization (WHO) Rotavirus Surveillance Network has proposed including three EIA kits in the WHO-GSM (Global Management System/Système Mondial de Gestion ) catalogue for easy procurement of EIA kits by participating rotavirus surveillance network laboratories. Objectives In this study, we conducted a comparative analysis of 3 commercially available enzyme immunoassay kits: PremierTM Rotaclone® (Meridian Bioscience, Inc.), ProSpecTTM (Oxoid, Ltd.) and RIDASCREEN® (R-biopharm AG) for rotavirus diagnostics. Study design Using reverse-transcriptase-PCR (RT-PCR) as the gold standard, the 3 EIA kits were evaluated by testing a stool panel consisting of 56 rotavirus-positive and 54 rotavirus negative samples. Results The sensitivities of the PremierTM Rotaclone®, ProSpecTTM and RIDASCREEN® kits were 76.8%, 75% and 82.1% respectively, but did not differ significantly. The specificity of all the 3 kits was 100%. The use of RT-PCR as a gold standard lowered the observed sensitivity of all 3 EIA kits but helps to reduce equivocal results that can be seen when another EIA or other non-molecular methods are used as the reference assay in comparison studies. Conclusion Our study found that all three kits are suitable for use by rotavirus surveillance programs. PMID:23850415

  4. Behavior Change and Health-Related Interventions for Heterosexual Risk Reduction Among Drug Users

    PubMed Central

    SEMAAN, SALAAM; JARLAIS, DON C. DES; MALOW, ROB

    2007-01-01

    Prevention of heterosexual transmission of HIV between and from drug users is important for controlling the local and global HIV heterosexual epidemic. Sex risk reduction interventions and health-related interventions are important for reducing the sex risk behaviors of drug users. Sex risk reduction interventions address individual-level, peer-level, and structural-level determinants of risk reduction. Health-related interventions include HIV counseling and testing, prevention and treatment of sexually transmitted diseases, and delivery of highly active antiretroviral therapy. It is important to adapt effective interventions implemented in resource-rich countries to the realities of the resource-constrained settings and to address relevant contextual factors. RESUMEN Il est important de prévenir la transmission hétérosexuelle du VIH à partir des usagers de drogue pour contrôler l’épidémie hétérosexuelle locale et mondiale de VIH. Des interventions ciblant à la fois la réduction de risque sexuel et la santé des usagers de drogue sont nécessaires. Les interventions de réduction de risque sexuel prennent en compte le niveau individuel, le niveau des pairs et celui des déterminants structurels de la réduction des risques. Les interventions visant l’amélioration de la santé comprennent le conseil et le dépistage du VIH, la prévention et le traitement des infections sexuellement transmissibles et la prescription d’antirétroviraux. Il est important d’adapter les interventions efficaces mises en place dans les pays riches aux réalités des contextes de pays à ressources limitées et de tenir compte des facteurs contextuels pertinents. PMID:17002987

  5. Protéger les nourrissons contre la coqueluche

    PubMed Central

    Gilley, Meghan; Goldman, Ran D.

    2014-01-01

    Résumé Question Compte tenu du taux à la hausse de la coqueluche chez les enfants, plusieurs familles m’ont demandé quels moyens prendre pour protéger leurs tout-petits de cette infection. Quelles devraient être mes recommandations à ces familles? Réponse La coqueluche est une maladie évitable qui est endémique dans le monde entier. Chez les adultes, la coqueluche cause une maladie bénigne semblable à un rhume, suivie d’une toux persistante. Chez les nourrissons, elle peut causer de l’apnée, des convulsions, une encéphalopathie, une bronchopneumonie et la mort. Les décès dus à la coqueluche se produisent dans 86 % des cas chez des nourrissons de moins de 4 mois. La stratégie du cocooning, c’est-à-dire la vaccination des adultes en étroit contact avec des nourrissons, est recommandée par de nombreuses agences mondiales et nationales, mais elle ne prévient probablement que 20 % des cas de coqueluche chez les nourrissons. La vaccination durant la grossesse est plus efficace, mais elle n’est pas encore approuvée au Canada. Il n’a pas été démontré que la vaccination à la naissance soit uniformément efficace et elle n’est donc pas recommandée à l’heure actuelle.

  6. La tuberculose pulmonaire et le tabac: à propos de 100 cas

    PubMed Central

    Janah, Hicham; Souhi, Hicham; Kouissmi, Hatim; Marc, Karima; Zahraoui, Rachida; Benamor, Jouda; Soualhi, Mona; Bourkadi, Jamal Eddine

    2014-01-01

    Le tabagisme et la tuberculose sont deux enjeux majeurs de santé publique au niveau mondial, en particulier dans les pays émergents. Pour déterminer les particularités cliniques, radiologiques, bactériologiques et thérapeutiques de la tuberculose pulmonaire chez les sujets tabagiques nous avons mené une étude prospective au service de phtisiologie de l'hôpital Moulay Youssef sur une période de 10 mois, portant sur 100 nouveaux cas de tuberculose pulmonaire, répartis en 2 groupes, 50 patients tabagiques: Groupe A et 50 patients non tabagiques: Groupe B. Tous nos patients étaient de sexe masculin, l’âge moyen était de 41 ans ± 12 chez le groupe A et de 36 ans ± 16 chez le groupe B. Le délai de consultation était plus long chez les tabagiques, la médiane était de 60j (30; 98) contre 40j (30; 60), la symptomatologie clinique était variable chez les deux groupes, dominée par les expectorations chez les tabagiques 96% contre 60%. Les lésions radiologiques étaient similaires chez les deux groupes ainsi que la charge bacillaire. Tous les patients ont été mis sous traitement antituberculeux. Après un mois du traitement, la Bacilloscopie était négative chez 50% du groupe A contre 66% chez le groupe B. la régression des lésions radiologiques était similaire chez les deux groupes. Le retard diagnostique et le retard de négativation des frottis sont les principales particularités de la tuberculose pulmonaire du sujet tabagique. Le sevrage tabagique doit faire partie intégrante de la prise en charge des patients atteints de tuberculose. PMID:25821545

  7. Évolution de leucémies myéloïdes chroniques sous nilotinib après échec a l'imatinib

    PubMed Central

    Sawadogo, Salifo; Hien, Francis Michel; Ouédraogo, Macaire Sampawendé; Drabo, Youssouf Joseph

    2014-01-01

    C'est une étude observationnelle prospective ouverte: quatre leucémies myéloïdes chroniques résistant ou intolérant à l'Imatinib ont été traitées par le Nilotinib. Elles ont été incluses dans le programme GIPAP et suivies selon les recommandations de “European LeukemiaNet”. Trois ont un score de Sokal de haut risque et une de bas risque. Deux étaient hypertendues. Mises sous Nilotinib, il y a eu deux rémissions cytogénétiques complètes et deux échecs. Le traitement a été interrompu chez les deux rémissions complètes, l'un pour effet secondaire du Nilotinib et l'autre pour changement de pays. Les deux échecs sont dus à des résistances. Le Nilotinib réduisant la fréquence des mutations des leucémies myéloïdes chroniques à haut risque et risque intermédiaire, il serait judicieux d'utiliser ce produit en première intention dans ces cas - ci pour réduire la charge des examens complémentaires. Les pays à bas revenu confrontés à des problèmes de survie ont besoin de la solidarité mondiale pour prendre en charge les leucémies myéloïdes chroniques. PMID:25419280

  8. Interdire aux enfants et aux adolescents de moins de 18 ans l’accès aux établissements commerciaux de bronzage

    PubMed Central

    Taddeo, Danielle; Stanwick, Richard

    2012-01-01

    RÉSUMÉ Le nombre de mélanomes cutanés malins a plus que triplé depuis 35 ans. Puisque les dommages sont cumulatifs, l’exposition aux rayonnements ultraviolets tôt dans la vie accroît le risque, qui augmente davantage avec l’utilisation de sources artificielles de rayonnements ultraviolets. Il peut falloir des années pour évaluer les répercussions et l’étendue complètes des dommages causés par le bronzage artificiel à longueur d’année, compte tenu de la longue période de latence de la plupart des cancers de la peau. Les adolescents fréquentent souvent les salons de bronzage, les filles s’y rendant davantage et de manière soutenue. L’industrie du bronzage conteste la classification de cancérigène physique de groupe 1 qu’attribuent au bronzage artificiel l’Organisation mondiale de la santé et le Centre international de recherche sur le cancer. Les salons de bronzage cherchent à établir et à maintenir une clientèle chez les adolescents. Par conséquent, la Société canadienne de pédiatrie s’ajoute à d’autres organismes de santé réputés pour appuyer l’interdiction des établissements commerciaux de bronzage aux enfants et adolescents de moins de 18 ans.

  9. Design and synthesis of a novel 2-oxindole scaffold as a highly potent and brain-penetrant phosphodiesterase 10A inhibitor.

    PubMed

    Yoshikawa, Masato; Kamisaki, Haruhi; Kunitomo, Jun; Oki, Hideyuki; Kokubo, Hironori; Suzuki, Akihiro; Ikemoto, Tomomi; Nakashima, Kosuke; Kamiguchi, Naomi; Harada, Akina; Kimura, Haruhide; Taniguchi, Takahiko

    2015-11-15

    Highly potent and brain-penetrant phosphodiesterase 10A (PDE10A) inhibitors based on the 2-oxindole scaffold were designed and synthesized. (2-Oxo-1,3-oxazolidin-3-yl)phenyl derivative 1 showed the high P-glycoprotein (P-gp) efflux (efflux ratio (ER)=6.2) despite the potent PDE10A inhibitory activity (IC50=0.94 nM). We performed an optimization study to improve both the P-gp efflux ratio and PDE10A inhibitory activity by utilizing structure-based drug design (SBDD) techniques based on the X-ray crystal structure with PDE10A. Finally, 1-(cyclopropylmethyl)-4-fluoro-5-[5-methoxy-4-oxo-3-(1-phenyl-1H-pyrazol-5-yl)pyridazin-1(4H)-yl]-3,3-dimethyl-1,3-dihydro-2H-indol-2-one (19e) was identified with improved P-gp efflux (ER=1.4) and an excellent PDE10A inhibitory activity (IC50=0.080 nM). Compound 19e also exhibited satisfactory brain penetration, and suppressed PCP-induced hyperlocomotion with a minimum effective dose of 0.3mg/kg by oral administration in mice. PMID:26494583

  10. PCR detection of cytK gene in Bacillus cereus group strains isolated from food samples.

    PubMed

    Oltuszak-Walczak, Elzbieta; Walczak, Piotr

    2013-11-01

    A method for detection of the cytotoxin K cytK structural gene and its active promoter preceded by the PlcR-binding box, controlling the expression level of this enterotoxin, was developed. The method was applied for the purpose of the analysis of 47 bacterial strains belonging to the Bacillus cereus group isolated from different food products. It was found that the majority of the analyzed strains carried the fully functional cytK gene with its PlcR regulated promoter. The cytK gene was not detected in four emetic strains of Bacillus cereus carrying the cesB gene and potentially producing an emetic toxin - cereulide. The cytotoxin K gene was detected in 4 isolates classified as Bacillus mycoides and one reference strain B. mycoides PCM 2024. The promoter region and the N-terminal part of the cytK gene from two strains of B. mycoides (5D and 19E) showed similarities to the corresponding sequences of Bacillus cereus W23 and Bacillus thuringiensis HD-789, respectively. It was shown for the first time that the cytK gene promoter region from strains 5D and 19E of Bacillus mycoides had a similar arrangement to the corresponding sequence of Bacillus cereus ATCC 14579. The presence of the cytK gene in Bacillus mycoides shows that this species, widely recognized as nonpathogenic, may pose potential biohazard to human beings. PMID:24060693

  11. Temperature-Dependent Rate Constants and Substituent Effects for the Reactions of Hydroxyl Radicals With Three Partially Fluorinated Ethers

    NASA Technical Reports Server (NTRS)

    Hsu, K.-J.; DeMore, W. B.

    1995-01-01

    Rate constants and temperature dependencies for the reactions of OH with CF3OCH3 (HFOC-143a), CF2HOCF2H (HFOC-134), and CF3OCF2H (HFOC-125) were studied using a relative rate technique in the temperature range 298-393 K. The following absolute rate constants were derived: HFOC-143a, 1.9E-12 exp(-1555/T); HFOC-134, 1.9E-12 exp(-2006/T); HFOC-125, 4.7E-13 exp(-2095/T). Units are cm(exp 3)molecule(exp -1) s(exp -1). Substituent effects on OH abstraction rate constants are discussed, and it is shown that the CF3O group has an effect on the OH rate constants similar to that of a fluorine atom. The effects are related to changes in the C-H bond energies of the reactants (and thereby the activation energies) rather than changes in the preexponential factors. On the basis of a correlation of rate constants with bond energies, the respective D(C-H) bond strengths in the three ethers are found to be 102, 104, and 106 kcal/mol, with an uncertainty of about 1 kcal/mol.

  12. VERY HIGH ENERGY {gamma}-RAY EMISSION FROM PASSIVE SUPERMASSIVE BLACK HOLES: CONSTRAINTS FOR NGC 1399

    SciTech Connect

    Pedaletti, G.; Wagner, S. J.; Rieger, F. M.

    2011-09-10

    Very high energy (VHE, >100 GeV) {gamma}-rays are expected to be emitted from the vicinity of supermassive black holes (SMBHs), irrespective of their activity state. In the magnetosphere of rotating SMBH, efficient acceleration of charged particles can take place through various processes. These particles could reach energies up to E {approx} 10{sup 19} eV. VHE {gamma}-ray emission from these particles is then feasible via leptonic or hadronic processes. Therefore, passive systems, where the lack of a strong photon field allows the VHE {gamma}-rays to escape, are expected to be detected by Cherenkov telescopes. We present results from recent VHE experiments on the passive SMBH in the nearby elliptical galaxy NGC 1399. No {gamma}-ray signal has been found, neither by the H.E.S.S. experiment nor in the Fermi data analyzed here. We discuss possible implications for the physical characteristics of the system. We conclude that in a scenario where particles are accelerated in vacuum gaps in the magnetosphere, only a fraction {approx}0.3 of the gap is available for particle acceleration, indicating that the system is unlikely to be able to accelerate protons up to E {approx} 10{sup 19} eV.

  13. Amorphous silicon carbide films prepared using vaporized silicon ink

    NASA Astrophysics Data System (ADS)

    Masuda, Takashi; Shen, Zhongrong; Takagishi, Hideyuki; Ohdaira, Keisuke; Shimoda, Tatsuya

    2014-03-01

    The deposition of wide-band-gap silicon films using nonvacuum processes rather than conventional vacuum processes is of substantial interest because it may reduce cost. Herein, we present the optical and electrical properties of p-type hydrogenated amorphous silicon carbide (a-SiC:H) films prepared using a nonvacuum process in a simple chamber with a vaporized silicon ink consisting of cyclopentasilane, cyclohexene, and decaborane. The incorporation of carbon into the silicon network induced by the addition of cyclohexene to the silicon ink resulted in an increase in the optical band gap (Eg) of films from 1.56 to 2.11 eV. The conductivity of films with Eg < 1.9 eV is comparable to that of conventional a-SiC:H films prepared using a vacuum process, while the films with Eg > 1.9 eV show lower conductivity than expected because of the incorporation of excess carbon without the formation of Si-C bonds.

  14. Seismic evaluation of NOSR 2. Naval Oil Shale Reserves management support and systems engineering project. [Utah

    SciTech Connect

    Not Available

    1982-01-01

    In June 1981, the Department of Energy (DOE) elected to conduct a seismic evaluation of NOSR 2 in Utah. This survey was carried out by TRW for DOE as part of the resource assessment of the Naval Oil Shale Reserves. The objective of the seismic survey was to determine if there are any structures on the Reserve which may have trapped hydrocarbons. An evaluation of the results indicated the elongated anticlinal structure in the southeast corner (Tabyago Dome) does have dip reversal and that there is a closed structure. Centered in Section 21, T13S, R19E, that structure has a high probability of having trapped hydrocarbons. Any well drilled on that structure should test all the potential producing formations down to the Pre-Cambrian (15,000 feet). It is also possible that several stratigraphic traps exist on a north-trending anticline in R19E. The seismic survey was carried out during August-September 1981 when the Seismograph Service Corporation (SSC) shot an additional eight seismic lines over the entire Reserve. With the three existing commercial seismic lines, a total of 66.25 miles of seismic profiles were available for the evaluation. Additional geologic information from existing reports and data from producing areas which surround the Reserve also were used in making the final assessment. 9 references, 7 figures, 3 tables.

  15. DYNAMICS OF THE REACTION OF N{sup +} WITH H{sub 2}. V. REACTIVE AND NON-REACTIVE SCATTERING OF N{sup +}({sup 3}p) AT RELATIVE ENERGIES BELOW 3.6 eV.

    SciTech Connect

    Hansen, Steven G.; Farrar, James M.; Mahan, Bruce H.

    1980-05-01

    We have measured product velocity vector distributions for the processes N{sup +}({sup 3}P)(H{sub 2},H)NH{sup +} and N{sup +}({sup 3}P)(H{sub 2},H{sub 2})N+ in the initial relative energy ranges of 0.98~3.60 eV and 0.66~ 2.50 eV respectively using the crossed beam technique. At energies below about 1.9 eV the predominance of a long-lived NH{sub 2}{sup +} complex is inferred from isotropic reactive scattering and a backscattered peak in the non-reactive distributions. Above 1.9 eV there is still a substantial interaction between all three atoms. The dynamics are adequately explained by a mechanism which involves accessing the deep {sup 3}B{sub 1} potential well through an avoided crossing with the {sup 3}A{sub 2} surface when the ·symmetry is relaxed from C{sub 2v} to C{sub s}. The reaction of electronically excited metastable ions, probably N{sup +}({sup 1}D), is seen as a forward peak in the reactive distributions.

  16. Ion-molecule interactions in crossed-beams. [N/sup +/-H/sub 2/; F/sup +/-H; CO/sub 2//sup +/-D/sub 2/

    SciTech Connect

    Hansen, S.G.

    1980-09-01

    Interactions of the ions N/sup +/, F/sup +/, and CO/sub 2//sup +/ with H/sub 2/ and/or its isotopes were examined using the crossed-beam technique in the low (< 4 eV) initial relative energy. For the reaction N/sup +/(/sup 3/P) + H/sub 2/ ..-->.. NH/sup +/ + H, complex formation dominates up to 1.9 eV and a substantial interaction occurs between all collision partners up to 3.6 eV. The distribution of N/sup +/ scattered nonreactively from H/sub 2/ also showed a long-lived complex channel below 1.9 eV. The reaction F/sup +/(/sup 3/P) + H/sub 2/ ..-->..FH/sup +/ + H proceeded by a direct reaction mechanism at 0.20 to 1.07 eV. The reaction CO/sub 2//sup +/ + D/sub 2/ ..-->.. DCO/sub 2//sup +/ + D gives asymmetric product distributions at 0.27 eV and above, indicating a direct reaction mechanism. Results indicated that there are probably barriers in the exit channels for DCO/sub 2//sup +/, DCO/sup +/, and D/sub 2/O/sup +/ products. The electronic state distributions of the N/sup +/, F/sup +/, and CO/sub 2//sup +/ beams was investigated using beam attenuation and total luminescence techniques.

  17. Répartition des dépôts carbonatés du Lias inférieur et moyen le long de la côte atlantique du Maroc: conséquences sur la paléogéographie de l'Atlantique naissant

    NASA Astrophysics Data System (ADS)

    Dresnay, Renaud Du

    Along the Atlantic coast of Morocco a series of embayments or basins including the Essaouira-Jebel Amsittène and Tarfaya-Laayoune basins, contain marine sediments which may attain considerable thickness and whose Early Jurassic (Liassic) age has been well documented. This paper describes Liassic deposits from six exposures or drill holes between the Saharan coast of Tarfaya and the Essaouira-Jebel Amsittène region. These Atlantic basins do not connect with the marine troughs of the High and Middle Atlas, which follow a Mediterranean Tethys trend, but are separated from them by a SSW-NNE trending threshold made up of the axial portion of the central Hercynian Massif (Moroccan Meseta). Their opening to the ancestral Mediterranean must have been farther north, probably by means of interconnecting, WSW-ENE trending rift-related graben trenches, possibly starting with the Rharb (Kenitra) basin. More likely, however, openingsexisted beneath the present nappes of the Rif and along the undoubtedly wide fracture zone represented by the Azores-Gibraltar line separating the Rif terrain from that of the Betic Cordilleras (both of which contain well dated marine Hettangian). Farther SW, probably hidden by the sedimentary prism of the African continental shelf, connections may exist with the Liassic occurrence of Central America, as already suggested by Avias (1953. Sci. Terre1 (1), 1-276; 1956. 20° Congr. géol. Intern Mexico, Secc. II, 1-5), shown in a figure by Erben (1956b. Neues Jb. geol. paläontol. Abh., Stuttgart 103, 28-79), and subsequently upheld by Hallam (1971a. J. Geol. Chicago79 (2), 129-157; 1983. Palaeogeogr. P. clim. P. ecol.43, 181-193) and Thierry (1982. Bull. Soc. géol. Fr., Sér. 7, 24, 1053-1067). These lines of communication would have centered on a "Panamanian Strait" ("Panama Strasse") and would have permitted faunal migrations, in particular towards South America. Migrations of certain European and Mesogean faunal species have recently been

  18. How metallic is the binding state of indium hosted by excess-metal chalcogenides in ore deposits?

    NASA Astrophysics Data System (ADS)

    Ondina Figueiredo, Maria; Pena Silva, Teresa; Oliveira, Daniel; Rosa, Diogo

    2010-05-01

    Radiation Facility, in Grenoble/France). Polymetallic chalcogenide minerals and various model compounds displaying distinct bonding situations of indium to other ligands (oxygen and halides) were studied. Encouraging results from a first experiment [5] showed the presence of a "white line" in the XANES spectra collected from InF3 and from In-hosting bornite; however, the impossibility of clearly identifying the nanoscale phase hosting indium in sulphide ore samples has hindered a full interpretation of X-ray absorption data. The crystal chemistry of indium in natural chalcogenides is now reanalysed and XANES results obtained so far for polymetallic sulphides are accordingly re-evaluated, disclosing a challenging clue for indium binding state in these host minerals within sulphide ores. [1] M.O. Figueiredo et al. (2007) Procd. 9th Biennial SGA Mtg., Dublin/Ireland, edt. C. Andrew et al., 1355-1357. [2] O.C. Gaspar (2002) Canad. Miner. 40, 611-636. [3] M.O. Figueiredo & T.P. Silva (2009) ICANS 23, 23rd Int. Conf. Amorphous & Nano-crystalline Semiconductors, Netherlands, August 23-28. Poster ID 229 (abstract). [4] T. Seifert & D. Sandmann (2002) Ore Geol. Reviews 28, 1-31. [5] M.O. Figueiredo & T.P. Silva (2009) XVIII Int. Mater. Res. Congr., Mexico, August 16-20. Symp. 20, Poster nr. 1 (abstract). * Work developed within the research project PTDC/CTE-GIN/67027/2006 financed by the Portuguese Foundation for Science & Technology (FCT/MCTES). The financial support from EU to perform the experiments at the ESRF is also acknowledged.

  19. Systematic High-Resolution Remote-Sensing Investigation of Martian South Polar Landforms: Thermal Contraction Polygons

    NASA Astrophysics Data System (ADS)

    van Gasselt, Stephan; Hao, Jingyan

    2015-04-01

    landforms and combine results of two polar surveys. The work presented here provides a detailed assessment of data coverage, a review of polygonal landform types and of their distribution based on CTX observations. [1] Thomas et al. (2000): Nature, 404(6774): 161-164. [2] Kieffer (2003): 6th Int. Conf. Mars, #3158. [3] Piqueux & Christensen (2008): J. Geophys. Res., 113(E2), CiteID E02006. [4] Mangold (2005): Icarus, 174(2): 336-359. [5] van Gasselt et al. (2006): Europ. Planet. Sci. Congr., #629. [6] van Gasselt et al. (2005): J. Geophys. Res., 110(E8), CiteID E08002. [7] Byrne & Ingersoll (2003): Science, 299(5609): 1,057-1,053 [8] Piqueux et al. (2003): J. Geophys. Res., 108(E8), CiteID 5084. [9] Pilorget et al. (2013): J. Geophys. Res. 118(12): 2,520-2,536. [10] James et al. (2010): Icarus, 208(1): 82-85. [11] Portyankina et al. (2010): Icarus, 205(1): 311-320. [12] Thomas et al. (2010): Icarus, 205(1): 296-310. [13] Hansen et al. (2010): Icarus, 205(1): 283-295.

  20. Deep seated gravitational slope deformations and large landslides: implications on landslide hazard of urban areas and coastal erosion phenomena of Mount Poro headland

    NASA Astrophysics Data System (ADS)

    Guerricchio, A.; Simeone, V.

    2012-04-01

    square kilometers. Its movement towards NW produced a typical coastline, with a strong progradation towards NW and W from Punta della Tonnara to Parghelia and up to Fiumara della Ruffa (WSW of Tropea). The DSGSD involves the granitic bedrock as well as the transgressive Tortonian deposits, made by sands with the presence of Clypeasters, which are topped by arenaceous banks, for a total depth of 150 m. DSGSDs involving granitic rocks were probably due to more deformable lithotypes, like biotite schists, which work as substratum of granitic rocks at a not very deep depth, like in other areas of Calabria. Finally, the slow sliding towards N and NW of the landslide shapes the coast like a bow, thus causing strong erosion phenomena of the coastline. Ietto A & Calcaterra D. (1988). Deformazioni gravitative profonde e tettonica presso Tropea (M.te Poro, Calabria)", Memorie della Societa Geologica Italiana, 41, pp. 911-915, Rome, Italy. Guerricchio A. (2000). La fragilità del territorio dell'Italia centro-meridionale desumibile da immagini da satellite. X Congr. Naz. dei Geologi. International Conference: Il Territorio fragile; I, 443-482, Rome, Italy.

  1. Prelude and first decade, 1951-1961

    NASA Astrophysics Data System (ADS)

    Shepherd, L. R.

    The initiative leading to the establishment of the International Astronautical Federation (IAF) was taken in 1949 by the Stuttgart based Gesellschaft für Weltraumforschung (GfW), who proposed to other astronautical societies that a conference should be arranged to establish mutual co-operation. The British Interplanetary Society (BIS) agreed to organize such a conference in London in 1951, but in the interim the Groupement Astronautique Français (GAF) arranged a preliminary meeting to set up the agenda for the London meeting and to define its objectives. Representatives from astronautical groups in seven European countries and one South American society met in Paris in October 1950. Their meetings were preceded, on 30 September, by a large public gathering organized by the GAF, in the Sorbonne and was designated the Premier Congrès International d'Astronautique, a style which was to be adopted, in its English translation, for the subsequent annual conferences of the IAF. The representatives agreed that the objective of the London conference should be to create a federation of autonomous national astronautical societies, whose main purpose would be to provide an annual forum where these societies would meet. The London conference in September 1951, held in the City of Westminster, following the Paris precedent, was designated the IInd International Astronautical Congress. Astronautical and rocket societies from the ten countries were represented and became signatories to the agreement founding the IAF on 4 September 1951. The London congress set the pattern for subsequent congresses, in particular introducing technical lecture sessions. At the IIIrd Congress, held in Stuttgart, the first under the aegis of the newly founded IAF, a constitution was agreed and a Finance Committee was elected. The Constitution established that the Federation should be registered in Switzerland and be governed by a council of voting members—one only from each country. Subsequent

  2. An explanation for the chotic structure of the poles based on a new concept concerning the formation of the Moon

    NASA Astrophysics Data System (ADS)

    Seguignes, M.

    areas the way in which the gravitational sealing of the Moon occurred. the future modalities of an informative exploration of the polar regions. Bibliography Hubbard-GS; Feldman-W; Cox-SA; Smith-MA; Chu-Thielbar -L. 2002 : Lunar Prospector: First results and lessons learned ACTA-ASTRONAUTICA. JAN; 50 (1) : 39-47 Stankevich-DG; Shkuratov-YG; Petrov-DV 2001 Estimation of the area of the perpetually shaded lunar surface SOLAR-SYSTEM-RESEARCH. NOV-DEC; 35 (6) : 452-457 Séguignes M G. 2002 : Towards another theory for the formation of the moon. Poster 27ème congres of European Geophysical Society. Nice, 2002

  3. Emergent Propulsion Systems

    NASA Astrophysics Data System (ADS)

    El-Fakdi Sencianes, Andres

    2002-01-01

    the propellant. The propellant is a plasma that reaches extreme temperatures. Rockets tend to work much better the hotter the exhaust is. Thrust from the plasma engine could boost a spacecraft for a longer time and with better efficiency than conventional engines. Solar Windsurfing: A technology that uses a magnetic balloon to capture ionized particles shed by the Sun, "sailing" through space by taking use of the pressure of the sun's rays. All that is needed is a thin sheet of reflective material. Solar photons bounce off and transfer momentum to the sail, allowing the spacecraft to accelerate without expending fuel. General problems: -The electrostatic impact of the plasma created by electric thruster on spacecraft charging. -The influence of plasma ejected from the thruster on solar panel performances. -Creation of parasite currents in the structure that may disturb sensitive equipment. -... in 300 words but I think that you will have a general idea about my work and what The Astronautical Congres represents to me.

  4. Role for the beta-adrenoceptor-coupled adenylate cyclase in the ontogenetic subsensitivity to isoproterenol in the embryonic chick ventricle

    SciTech Connect

    Smith, C.J.

    1985-01-01

    Isoproterenol (ISO) increases contractility and cyclic AMP content in ventricles of embryonic and hatched chicks. A transient decrease in beta-agonist sensitivity for both effects is seen in 18 day embryos (10E). Beta-adrenoceptor-coupled adenylate cylase (AC) and receptor binding were characterized in 14,000xg particulates and purified membranes from the ventricles of 10-11E, 17-19E and week-old chicks (5-6H). In crude particulates, the K/sub act/ for ISO (+100 ..mu..M Gpp(NH)p)-stimulated AC is greatest in the 17-19E. Maximal (ISO + Gpp(NH)p)-AC of the 11E is two-fold greater and NaF-AC is 30% greater than those of the 17-19E and 5-6 H. All age groups have comparable catalytic AC. All age groups have comparable K/sub d/'s for /sup 3/H-dihydroalprenolol (5-11 nM), while the 18E has 40% fewer receptors than the 11E and 5-6H. In particulates or membranes, K/sub act/ values for Gpp(NH)p, NaF, MnCl> and forskolin are unchanged with age. In membranes, K/sub act/ values for ISO plus guanine nucleotide (G) and maximal (ISO + G)-AC are similar in all ages. The net effect of ISO ((ISO + G) minus G) is least while that of G (G minus basal) is greatest in the 18E. Whereas /sup 32/P-labeling of a 42 kd protein by cholera toxin is lowest (25% decrease) in particulates of the 18E, labeling of a 39-41 kd doublet by pertussis toxin decreases continuously (by 50%) with age. All age groups have comparable K/sub d/'s (10-13 pM) for (/sup 125/I)-cyanopindolol (CYP). These data indicate that a transient decrease in receptor number and receptor-N/sub s/ (guanine nucleotide-sensitive) coupling in the 18E contribute to the subsensitivity to beta-agonist.

  5. Effect of p–d hybridization, structural distortion and cation electronegativity on electronic properties of ZnSnX{sub 2} (X=P, As, Sb) chalcopyrite semiconductors

    SciTech Connect

    Mishra, S.; Ganguli, B.

    2013-04-15

    Significant effects of p–d hybridization, structural distortion and cation-electro-negativity are found on band gap in ZnSnX{sub 2} (X=P, As, Sb). Our study suggests these compounds to be direct band gap semiconductors with band gaps of 1.23, 0.68 and 0.19 eV respectively. Lattice constants, tetragonal distortion (η), anion displacement, bond lengths and bulk moduli are calculated by Density Functional Theory based on Tight binding Linear Muffin-Tin orbital method. Our result of structural properties is in good agreement with the available experimental and other theoretical results. Calculated band gaps also agree well with the experimental works within LDA limitation. Unlike other semiconductors in the group II–IV–V{sub 2}, there is a reduction in the band gap of 0.22, 0.20 and 0.24 eV respectively in ZnSnX{sub 2} (X=P, As, Sb) due to p–d hybridization. Structural distortion decreases band gap by 0.20, 0.12 and 0.10 eV respectively. We find that cation electronegativity effect is responsible for increasing the band gap relative to their binary analogs GaInP{sub 2}, InGaAs{sub 2} and GaInSb{sub 2} respectively and increment are 0.13, 0.04 and 0.13 eV respectively. - Graphical abstract: One unit cell of ZnSnX{sub 2} (X=P, As, Sb) chalcopyrite semiconductor. Semiconductors ZnSnX{sub 2} (X=P, As, Sb) are found to be direct band gap semiconductors with band gaps 1.23, 0.68 and 0.19 eV respectively. The quantitative estimate of effects of p–d hybridization, structural distortion and cation electronegativity shows band gaps change significantly due to these effects. Highlights: ► ZnSnX{sub 2} (X=P, As, Sb) are direct band gap semiconductors. ► These have band gaps of 1.23 eV, 0.68 eV and 0.19 eV respectively. ► The band gap reduction due to p–d hybridization is 13.41%, 18.51% and 40% respectively. ► Band gap reduction due to structural distortion is 12.12%, 11.11% and 16.66% respectively. ► Band gap increases 8.38%, 3.70% and 21.31% respectively

  6. Progress towards a 30% efficient GaInP/Si tandem solar cells

    SciTech Connect

    Essig, Stephanie; Ward, Scott; Steiner, Myles A.; Friedman, Daniel J.; Geisz, John F.; Stradins, Paul; Young, David L.

    2015-08-28

    The performance of dual-junction solar cells with a Si bottom cell has been investigated both theoretically and experimentally. Simulations show that adding a top junction with an energy bandgap of 1.6 -1.9 eV to a standard silicon solar cell enables efficiencies over 38%. Currently, top junctions of GaInP (1.8 eV) are the most promising as they can achieve 1-sun efficiencies of 20.8% [1]. We fabricated mechanically stacked, four terminal GaInP/Si tandem solar cells using a transparent adhesive between the subcells. These tandem devices achieved an efficiency of 27% under AM1.5 g spectral conditions. Furthermore, higher efficiencies can be achieved by using an improved Si-bottom cell and by optimizing the dual-junction device for long-wavelength light and luminescent coupling between the two junctions.

  7. Progress towards a 30% efficient GaInP/Si tandem solar cells

    DOE PAGESBeta

    Essig, Stephanie; Ward, Scott; Steiner, Myles A.; Friedman, Daniel J.; Geisz, John F.; Stradins, Paul; Young, David L.

    2015-08-28

    The performance of dual-junction solar cells with a Si bottom cell has been investigated both theoretically and experimentally. Simulations show that adding a top junction with an energy bandgap of 1.6 -1.9 eV to a standard silicon solar cell enables efficiencies over 38%. Currently, top junctions of GaInP (1.8 eV) are the most promising as they can achieve 1-sun efficiencies of 20.8% [1]. We fabricated mechanically stacked, four terminal GaInP/Si tandem solar cells using a transparent adhesive between the subcells. These tandem devices achieved an efficiency of 27% under AM1.5 g spectral conditions. Furthermore, higher efficiencies can be achieved bymore » using an improved Si-bottom cell and by optimizing the dual-junction device for long-wavelength light and luminescent coupling between the two junctions.« less

  8. Indium nitride: A narrow gap semiconductor

    SciTech Connect

    Wu, J.; Walukiewicz, W.; Yu, K.M.; Ager III, J.W.; Haller, E.E.; Lu, H.; Schaff, W.J.

    2002-08-14

    The optical properties of wurtzite InN grown on sapphire substrates by molecular-beam epitaxy have been characterized by optical absorption, photoluminescence, and photomodulated reflectance techniques. All these three characterization techniques show an energy gap for InN between 0.7 and 0.8 eV, much lower than the commonly accepted value of 1.9 eV. The photoluminescence peak energy is found to be sensitive to the free electron concentration of the sample. The peak energy exhibits a very weak hydrostatic pressure dependence and a small, anomalous blueshift with increasing temperature. The bandgap energies of In-rich InGaN alloys were found to be consistent with the narrow gap of InN. The bandgap bowing parameter was determined to be 1.43 eV in InGaN.

  9. Development of Novel Biopolymer/Synthetic-Polymer/Iron Oxide Nanocomposites

    NASA Astrophysics Data System (ADS)

    Mena Montoya, Marleth; Carranza, Sugeheidy; Hinojosa, Moisés; González, Virgilio

    2009-03-01

    In this work we report the successful development of a family of magnetic nanocomposites based on chitosan or/and polyamide 6 matrix with dispersed iron oxide nanoparticles synthesized by chemical co-precipitation. The iron oxide contents varied from 5 up to 23 wt%, the nanocomposites were studied by FTIR, UV-vis, TGA, XRD, TEM and magnetometry. The FTIR analysis demonstrates an interaction between the amide group of the polyamide 6 and the ceramic material. In formic acid, the nanocomposites absorb in the UV-Vis range, and the magnitude of the band gap (optical), calculated using the band of higher wavelength, is between 2.16 and 2.19 eV. In nanocomposites with chitosan/polyamide 6 matrix the developed morphologies are spherulites of polyamide 6 surrounded by chitosan, with the iron oxide particles presumably in the form of ferrihidryte. The measured magnetic properties revealed a superparamagnetic character on the studied specimens.

  10. Studies of High Energy Particle Astrophysics

    SciTech Connect

    Nitz, David F; Fick, Brian E

    2014-07-30

    This report covers the progress of the Michigan Technological University particle astrophysics group during the period April 15th, 2011 through April 30th, 2014. The principal investigator is Professor David Nitz. Professor Brian Fick is the Co-PI. The focus of the group is the study of the highest energy cosmic rays using the Pierre Auger Observatory. The major goals of the Pierre Auger Observatory are to discover and understand the source or sources of cosmic rays with energies exceeding 10**19 eV, to identify the particle type(s), and to investigate the interactions of those cosmic particles both in space and in the Earth's atmosphere. The Pierre Auger Observatory in Argentina was completed in June 2008 with 1660 surface detector stations and 24 fluorescence telescopes arranged in 4 stations. It has a collecting area of 3,000 square km, yielding an aperture of 7,000 km**2 sr.

  11. Giant edge state splitting at atomically precise graphene zigzag edges

    NASA Astrophysics Data System (ADS)

    Wang, Shiyong; Talirz, Leopold; Pignedoli, Carlo A.; Feng, Xinliang; Müllen, Klaus; Fasel, Roman; Ruffieux, Pascal

    2016-05-01

    Zigzag edges of graphene nanostructures host localized electronic states that are predicted to be spin-polarized. However, these edge states are highly susceptible to edge roughness and interaction with a supporting substrate, complicating the study of their intrinsic electronic and magnetic structure. Here, we focus on atomically precise graphene nanoribbons whose two short zigzag edges host exactly one localized electron each. Using the tip of a scanning tunnelling microscope, the graphene nanoribbons are transferred from the metallic growth substrate onto insulating islands of NaCl in order to decouple their electronic structure from the metal. The absence of charge transfer and hybridization with the substrate is confirmed by scanning tunnelling spectroscopy, which reveals a pair of occupied/unoccupied edge states. Their large energy splitting of 1.9 eV is in accordance with ab initio many-body perturbation theory calculations and reflects the dominant role of electron-electron interactions in these localized states.

  12. Ar plasma induced deep levels in epitaxial n-GaAs

    SciTech Connect

    Venter, A.; Nyamhere, C.; Botha, J. R.; Auret, F. D.; Janse van Rensburg, P. J.; Meyer, W. E.; Coelho, S. M. M.; Kolkovsky, V. l.

    2012-01-01

    Ar plasma etching of n-type (Si doped) GaAs introduces several electron traps (E{sub c} - 0.04 eV, E{sub c} - 0.07 eV, E{sub c} - 0.19 eV, E{sub c} - 0.31 eV, E{sub c} - 0.53 eV, and E{sub c} - 0.61 eV). The trap, E{sub c} - 0.04 eV, labelled E1' and having a trap signature similar to irradiation induced defect E1, appears to be metastable. E{sub c} - 0.31 eV and E{sub c} - 0.61 eV are metastable too and they are similar to the M3/M4 defect configuration present in hydrogen plasma exposed n-GaAs.

  13. Enhancement of photocatalytic performance of plasmon-assisted metallic ion doped titania

    NASA Astrophysics Data System (ADS)

    Fan, Jimin; Zhao, Zhihuan; Gong, Chao; Cheng, Bin; Xue, Yongqiang; Yin, Shu

    2015-11-01

    Plasmonic assisted metallic ion doped titania was synthesized successfully by combining the hydrothermal and photoreduction methods. The chromium ion doping resulted to smaller particle size and preferable crystallinity than pure TiO2. Ag@AgI-TiO2-Cr showed the smallest band gap of 1.9 eV, corresponding to the wavelength range until 652 nm. The Ag-AgI plasmonic effect promoted electron transfer and accelerated photocatalytic reaction. Excellent visible light induced MO degradation was effectively realized. The sample Ag@AgI-TiO2-Cr exhibited the best photodegradation activity, which might be related to its smallest band gap, larger specific surface area of 178.3 m2 g-1 and the maximum equilibrium adsorption quantity of 18.0 mg/g.

  14. Control of the growth orientation and electrical properties of polycrystalline Cu2O thin films by group-IV elements doping

    NASA Astrophysics Data System (ADS)

    Ishizuka, Shogo; Akimoto, Katsuhiro

    2004-11-01

    The effects of group-IV element dopants on the structural and electrical properties of Cu2O thin films were studied. Similar dopant-induced behavior was found in the observed variations of the growth orientation and electrical properties of Si- and Ge-doped Cu2O thin films. Ge doping was found to induce electrically active acceptors with an activation energy of 0.18 eV, comparable to the 0.19 eV value of Si-doped Cu2O. These results suggest that locally formed silicate and germanate have the same effect on the structural and electrical properties of Cu2O. On the other hand, Sn and Pb likely act as donors when incorporated substitutionally onto Cu-lattice sites, although further study may be required to suppress self-compensation effects in Cu2O to achieve n-type conductivity.

  15. Fluorogenic ratiometric dipodal optode containing imine-amide linkages: exploiting subtle thorium (IV) ion sensing.

    PubMed

    Tayade, Kundan; Kaur, Amanpreet; Tetgure, Sandesh; Chaitanya, G Krishana; Singh, Narinder; Kuwar, Anil

    2014-12-10

    The (13E,19E)-N1',N3'-bis[4-(diethylamino)-2-hydroxybenzylidene]malonohydrazide (L) has been developed for the detection of Th(4+) ions using dual channel signalling system. The UV-vis absorbance and fluorescence spectroscopic data revealed the formation of L-Th(4+) complex in 1:1 equilibrium. The density functional theory (DFT) also confirms the optimum binding cavity for the recognition of metal ion. The binding constant computed from different mathematical models for an assembly of L-Th(4+). The detection limit of L for Th(4+) recognition is to a concentration down to 0.1 μM (0.023 μg g(-1)). The present sensing system is also successfully applied for the detection of Th(4+) ion present in soil near nuclear atomic plants. PMID:25441898

  16. Optical properties of colloidal aqueous synthesized 3 mercaptopropionic acid stabilized CdS quantum dots

    NASA Astrophysics Data System (ADS)

    Sumanth Kumar, D.; Jai Kumar, B.; Mahesh H., M.

    2016-05-01

    We have explored an easiest and simplest aqueous route to synthesize bright green luminescent CdS QDs using 3-Mercaptopropionic acid (MPA) as a stabilizer in air ambient for solar cell applications. The CdS quantum dots showed a strong quantum confinement effect with good stability, size and excellent photoluminescence. MPA Capping on CdS QDs was confirmed through FTIR. The Optical absorption spectrum revealed the CdS quantum dots are highly transparent in the visible region with absorption peak at 380 nm, confirming the quantum confinement. Photoluminescence showed an emission peak at 525 nm wavelength. The optical band gap energy was found to be 3.19 eV and CdS quantum dots radius calculated using Brus equation is 1.5 nm. The results are presented and discussed in detail.

  17. The antigenic similarity of human low density lipoproteins.

    PubMed

    LEVINE, L; KAUFFMAN, D L; BROWN, R K

    1955-08-01

    THE FOLLOWING HUMAN LOW DENSITY LIPOPROTEINS WERE PREPARED: beta-lipoproteins of densities greater than 1.040 (A, B,C) a beta-lipoprotein of -S(1.063) = 5 (D), a lipoprotein of -S(1.063) = 19 (E), and a lipoprotein of -S(1.063) = 70 (F). Data are presented which show the immunochemical homogeneity of the D lipoprotein rabbit-anti-D lipoprotein system. Cross-reactions between antibody to A and D lipoproteins and the above lipoproteins have been demonstrated by quantitative precipitation, quanitative complement fixation, and single and double diffusion in agar. The antigenic similarities appear to be associated with the protein portions of the molecule. The antisera produced did not differentiate the low density lipoprotein classes. PMID:13242737

  18. Detection of charged particles in thick hydrogenated amorphous silicon layers

    SciTech Connect

    Fujieda, I.; Cho, G.; Kaplan, S.N.; Perez-Mendez, V.; Qureshi, S.; Ward, W.; Street, R.A.

    1988-03-01

    We show our results in detecting particles of various linear energy transfer, including minimum ionizing electrons from a Sr-90 source with 5 to 12 micron thick n-i-p and p-i-n diodes. We measured W ( average energy to produce one electron-hole pair) using 17keV filtered xray pulses with a result W = 6.0 /+-/ 0.2eV. This is consistent with the expected value for a semiconductor with band gap of 1.7 to 1.9eV. With heavily ionizing particles such as 6 MeV alphas and 1 to 2 MeV protons, there was some loss of signal due to recombination in the particle track. The minimum ionizing electrons showed no sign of recombination. Applications to pixel and strip detectors for physics experiments and medical imaging will be discussed. 7 refs., 8 figs.

  19. Density functional theory with modified dispersion correction for metals applied to molecular adsorption on Pt(111).

    PubMed

    Andersson, M P

    2016-07-28

    We have performed density functional theory calculations using our modified DFT-D2 dispersion correction for metals to investigate adsorption of a range of molecules on Pt(111). The agreement between our calculations and experimental adsorption energies ranging from 0 to 3 eV was excellent with a mean absolute deviation of 0.19 eV and a maximum deviation of 0.37 eV. Our results show that the DFT-D2 semiempirical dispersion correction can provide accurate results also for describing adsorption on metals, provided that relevant physical properties of the system are taken into account, such as shorter ranged dispersion because of screening by the conducting electrons and a lower polarizability of the core electrons in metals compared to isolated atoms. PMID:27357643

  20. Group Theoretical Analysis of Vibrational Modes, Rovibronic Levels and Nuclear Spin Statistics of extended aromatic C48N12 Azafullerene

    SciTech Connect

    Balasubramanian, K

    2004-03-17

    We have presented a group theoretical analysis of the vibrational modes and rovibronic levels of a novel extended aromatic C{sub 48}N{sub 12} azafullerene. The nuclear spin multiplets and statistical weights of {sup 14}N spin-1 bosons, vibrational and rotational analysis and computed vibrational spectra are provided. We have also predicted the properties of the {sup 3}A{sub u}, {sup 3}E{sub g}, and {sup 3}E{sub u} excited states of C{sub 48}N{sub 12} that lie 1.9 eV above the {sup 1}A{sub g} ground state, and that the {sup 3}E{sub g} and {sup 3}E{sub u} states would undergo Jahn-Teller distortion into chiral structures with no symmetry and an achiral structure with C{sub i} symmetry.

  1. Exploring Mbar shock conditions and isochorically heated aluminum at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (invited)a)

    NASA Astrophysics Data System (ADS)

    Fletcher, L. B.; Lee, H. J.; Barbrel, B.; Gauthier, M.; Galtier, E.; Nagler, B.; Döppner, T.; LePape, S.; Ma, T.; Pak, A.; Turnbull, D.; White, T.; Gregori, G.; Wei, M.; Falcone, R. W.; Heimann, P.; Zastrau, U.; Hastings, J. B.; Glenzer, S. H.

    2014-11-01

    Recent experiments performed at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatter x-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using velocity interferometer system for any reflector have been measured. The combination of experiments fully demonstrates the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.

  2. Irregularity of the muon component in extensive air showers

    SciTech Connect

    Glushkov, A.V.; Makarov, I.T.; Nikiforova, E.S.

    1995-07-01

    Experimental data obtained from 1974 to 1992 at the Yakutsk array for muons with threshold energies E{sub {mu}} {ge} 1 GeV in extensive air showers (EAS) are analyzed. Periods of reliable detector operation are selected, and miscounts of muon detectors near their operation thresholds are thoroughly taken into account. Average lateral distribution functions (LDF) are obtained for EAS muons in the energy range E{sub 0} = 10{sup 17} - 5 x 10{sup 19} eV and in the zenith-angle range {theta}=0{degrees} - 60{degrees}. For energies E{sub 0} > 5 x 10{sup 18} eV, the LDF are shown to depend on E{sub 0} and {theta} in a substantially different manner than they do in the range of lower EAS energies. This irregularity is apparently associated with certain unknown processes or unknown primary particles involved in the development of EASs. 7 refs., 13 figs.

  3. Exploring Mbar shock conditions and isochorically heated aluminum at the Matter in Extreme Conditions end station of the Linac Coherent Light Source

    SciTech Connect

    Doppner, T.; LePape, S.; Ma, T.; Pak, A.; Turnbull, D.; Fletcher, L. B.; Lee, H. J.; Galtier, E.; Nagler, B.; Gauthier, M.; Heimann, P.; Hastings, J. B.; Zastrau, U.; Glenzer, S. H.; White, T.; Gregori, G.; Wei, M.; Barbrel, B.; Falcone, R. W.

    2014-08-11

    Recent experiments performed at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatterx-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using velocity interferometer system for any reflector have been measured. Furthermore, the combination of experiments fully demonstrates the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.

  4. High-Energy Density science at the Linac Coherent Light Source

    NASA Astrophysics Data System (ADS)

    Glenzer, S. H.; Fletcher, L. B.; Hastings, J. B.

    2016-03-01

    The Matter in Extreme Conditions end station at the Linac Coherent Light Source holds great promise for novel pump-probe experiments to make new discoveries in high- energy density science. In recent experiments we have demonstrated the first spectrally- resolved measurements of plasmons using a seeded 8-keV x-ray laser beam. Forward x-ray Thomson scattering spectra from isochorically heated solid aluminum show a well-resolved plasmon feature that is down-shifted in energy by 19 eV from the incident 8 keV elastic scattering feature. In this spectral range, the simultaneously measured backscatter spectrum shows no spectral features indicating observation of collective plasmon oscillations on a scattering length comparable to the screening length. This technique is a prerequisite for Thomson scattering measurements in compressed matter where the plasmon shift is a sensitive function of the free electron density and where the plasmon intensity provides information on temperature.

  5. Exploring Mbar shock conditions and isochorically heated aluminum at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (invited).

    PubMed

    Fletcher, L B; Lee, H J; Barbrel, B; Gauthier, M; Galtier, E; Nagler, B; Döppner, T; LePape, S; Ma, T; Pak, A; Turnbull, D; White, T; Gregori, G; Wei, M; Falcone, R W; Heimann, P; Zastrau, U; Hastings, J B; Glenzer, S H

    2014-11-01

    Recent experiments performed at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatter x-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using velocity interferometer system for any reflector have been measured. The combination of experiments fully demonstrates the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision. PMID:25430365

  6. Scanning tunneling spectroscopy of lead sulfide quantum wells fabricated by atomic layer deposition

    SciTech Connect

    Lee, W. J.; Dasgupta, N. P.; Jung, H. J.; Lee, J. R.; Sinclair, R.; Prinz, F. B.

    2010-11-10

    We report the use of scanning tunneling spectroscopy (STS) to investigate one-dimensional quantum confinement effects in lead sulfide (PbS) thin films. Specifically, quantum confinement effects on the band gap of PbS quantum wells were explored by controlling the PbS film thickness and potential barrier height. PbS quantum well structures with a thickness range of 1–20 nm were fabricated by atomic layer deposition (ALD). Two barrier materials were selected based on barrier height: aluminum oxide as a high barrier material and zinc oxide as a low barrier material. Band gap measurements were carried out by STS, and an effective mass theory was developed to compare the experimental results. Our results show that the band gap of PbS thin films increased as the film thickness decreased, and the barrier height increased from 0.45 to 2.19 eV.

  7. Autoionization of OCS by threshold photoelectron spectroscopy

    NASA Astrophysics Data System (ADS)

    Delwiche, Jacques; Hubin-Franskin, Marie-Jeanne; Guyon, Paul-Marie; Nenner, Irène

    1981-04-01

    Autoionization of carbonyl sulfide between 12 and 16 eV has been investigated by photoionization using the pulsed synchrotron radiation from ACO Orsay's storage ring. The threshold photoelectron spectrum and the total photoionization spectrum of carbonyl sulfide have been recorded at high resolution in the wavelength range between 112.0 and 65.0 nm (11-19 eV). Threshold energy electrons are observed in specific wavelength regions: (i) at excitation energies where the X˜, Ã, B˜, and C˜ ionic states are formed by a direct process; (ii) in the à state region where resonant autoionization to à can be understood classically within the Franck-Condon approximation; (iii) in the ÖX˜ Franck-Condon gap between 90 and 110 nm, where resonant autoionization leads to very sharp electron energy distribution strongly peaked at zero energy. Here the mechanism must be more complex.

  8. Carbon-doped SiO(x) nanowires with a large yield of white emission.

    PubMed

    Fabbri, Filippo; Rossi, Francesca; Negri, Marco; Tatti, Roberta; Aversa, Lucrezia; Dhanabalan, Sathish Chander; Verucchi, Roberto; Attolini, Giovanni; Salviati, Giancarlo

    2014-05-01

    The growth of SiOx nanowires (NWs) with intense white emission is reported. Due to carbon monoxide gas being used as a dopant precursor, carbon-doped under-stoichiometric silicon dioxide NWs are obtained. The doping of the NWs is studied by means of x-ray photoelectron spectroscopy, which allows to assess the presence of carbon atoms in the silicon oxide amorphous structure. The light emission properties are studied by means of cathodoluminescence spectroscopy, which shows three main emission bands set at 2.7 eV (blue), 2.3 eV (green) and 1.9 eV (red), resulting in the white emission. PMID:24736107

  9. Seroprevalence of Toxoplasma gondii infection in pigs in Jilin Province, Northeastern China.

    PubMed

    Xu, P; Cai, Y N; Leng, X; Wang, J; Ma, W; Mu, G D; Jiang, J; Liu, X Y; Wang, Z D; Zhao, Q; Yang, G L

    2015-03-01

    In the present study, a total of 1,235 porcine serum samples were collected from 9 counties in Jilin Province (40°52'~46°18'N,121°38'~131°19'E), northeastern China from August to October 2013, and the seroprevalence of Toxoplasma gondii infection was tested by indirect haemagglutination assay (IHA). The results showed that antibodies to T. gondii were found in 19.1% (95% confidence interval [CI], 16.9% to 21.3%), with higher seroprevalence in the breeding boars (28.6%, 95% CI, 20.0% to 37.2%), and breeding sows (32.0%, 95% CI, 25.2% to 38.9%). No significant difference was found among the slaughter pigs, fattening pigs and the piglets. These results indicated that infection with T. gondii in pigs is widespread in Jilin province, and is of public health concern. PMID:25801260

  10. Exploring Mbar shock conditions and isochorically heated aluminum at the MEC end station of the LCLS

    SciTech Connect

    Fletcher, L. B.; Lee, H. J.; SLAC, aff; Barbrel, B.; Gauthier, M.; Galtier, E.; Nagler, B.; Doppner, T.; LePape, S.; Ma, T.; Pak, A.; Turnbull, D.; White, T.; Gregori, G.; Wei, M.; Falcone, R. W.; Heimann, P.; Zastrau, U.; Hastings, J. B.; Glenzer, S. H.

    2015-02-05

    Recent experiments performed at the Matter in Extreme Conditions end station (MEC) of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatter x-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using Velocity Interferometer System for Any Reflector (VISAR) have been measured. The combination of experiments fully demonstrates the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.

  11. Exploring Mbar shock conditions and isochorically heated aluminum at the Matter in Extreme Conditions end station of the Linac Coherent Light Source

    DOE PAGESBeta

    Doppner, T.; LePape, S.; Ma, T.; Pak, A.; Turnbull, D.; Fletcher, L. B.; Lee, H. J.; Galtier, E.; Nagler, B.; Gauthier, M.; et al

    2014-08-11

    Recent experiments performed at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatterx-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using velocity interferometer system for any reflector have been measured. Furthermore, the combination of experiments fully demonstratesmore » the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.« less

  12. Highly conducting and wide band gap phosphorous doped nc-Si-QD/a-SiC films as n-type window layers for solar cells

    NASA Astrophysics Data System (ADS)

    Kar, Debjit; Das, Debajyoti

    2016-05-01

    Nano-crystalline silicon quantum dots (Si-QDs) embedded in the phosphorous doped amorphous silicon carbide (a-SiC) matrix has been successfully prepared at a low temperature (300 °C) by inductively coupled plasma assisted chemical vapor deposition (ICP-CVD) system from (SiH4 + CH4)-plasma with PH3 as the doping gas. The effect of PH3 flow rate on structural, optical and electrical properties of the films has been studied. Phosphorous doped nc-Si-QD/a-SiC films with high optical band gap (>1.9 eV) and superior conductivity (~10-2 S cm-1) are obtained, which could be appropriately used as n-type window layers for nc-Si solar cells in n-i-p configuration.

  13. 10 CFR Appendix E to Part 835 - Values for Establishing Sealed Radioactive Source Accountability and Radioactive Material Posting...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...-41 9.3E+06 Ca-45 1.1E+06 Sc-46 6.2E+01 Ti-44 1.5E+02 V-49 1.0E+08 Mn-53 7.5E+07 Mn-54 6.5E+01 Fe-55 2.9E+06 Fe-59 1.9E+02 Fe-60 8.1E+03 Co-56 3.9E+01 Co-57 2.3E+02 Co-58 1.3E+02 Co-60 1.7E+01 Ni-59 3.2E+06 Ni-63 1.3E+06 Zn-65 1.1E+02 Ge-68 5.6E+02 As-73 5.3E+02 Se-75 6.3E+01 Se-79 8.7E+05 Rb-83...

  14. 10 CFR Appendix E to Part 835 - Values for Establishing Sealed Radioactive Source Accountability and Radioactive Material Posting...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...-41 9.3E+06 Ca-45 1.1E+06 Sc-46 6.2E+01 Ti-44 1.5E+02 V-49 1.0E+08 Mn-53 7.5E+07 Mn-54 6.5E+01 Fe-55 2.9E+06 Fe-59 1.9E+02 Fe-60 8.1E+03 Co-56 3.9E+01 Co-57 2.3E+02 Co-58 1.3E+02 Co-60 1.7E+01 Ni-59 3.2E+06 Ni-63 1.3E+06 Zn-65 1.1E+02 Ge-68 5.6E+02 As-73 5.3E+02 Se-75 6.3E+01 Se-79 8.7E+05 Rb-83...

  15. 10 CFR Appendix E to Part 835 - Values for Establishing Sealed Radioactive Source Accountability and Radioactive Material Posting...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...-41 9.3E+06 Ca-45 1.1E+06 Sc-46 6.2E+01 Ti-44 1.5E+02 V-49 1.0E+08 Mn-53 7.5E+07 Mn-54 6.5E+01 Fe-55 2.9E+06 Fe-59 1.9E+02 Fe-60 8.1E+03 Co-56 3.9E+01 Co-57 2.3E+02 Co-58 1.3E+02 Co-60 1.7E+01 Ni-59 3.2E+06 Ni-63 1.3E+06 Zn-65 1.1E+02 Ge-68 5.6E+02 As-73 5.3E+02 Se-75 6.3E+01 Se-79 8.7E+05 Rb-83...

  16. 10 CFR Appendix E to Part 835 - Values for Establishing Sealed Radioactive Source Accountability and Radioactive Material Posting...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...-41 9.3E+06 Ca-45 1.1E+06 Sc-46 6.2E+01 Ti-44 1.5E+02 V-49 1.0E+08 Mn-53 7.5E+07 Mn-54 6.5E+01 Fe-55 2.9E+06 Fe-59 1.9E+02 Fe-60 8.1E+03 Co-56 3.9E+01 Co-57 2.3E+02 Co-58 1.3E+02 Co-60 1.7E+01 Ni-59 3.2E+06 Ni-63 1.3E+06 Zn-65 1.1E+02 Ge-68 5.6E+02 As-73 5.3E+02 Se-75 6.3E+01 Se-79 8.7E+05 Rb-83...

  17. 10 CFR Appendix E to Part 835 - Values for Establishing Sealed Radioactive Source Accountability and Radioactive Material Posting...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...-41 9.3E+06 Ca-45 1.1E+06 Sc-46 6.2E+01 Ti-44 1.5E+02 V-49 1.0E+08 Mn-53 7.5E+07 Mn-54 6.5E+01 Fe-55 2.9E+06 Fe-59 1.9E+02 Fe-60 8.1E+03 Co-56 3.9E+01 Co-57 2.3E+02 Co-58 1.3E+02 Co-60 1.7E+01 Ni-59 3.2E+06 Ni-63 1.3E+06 Zn-65 1.1E+02 Ge-68 5.6E+02 As-73 5.3E+02 Se-75 6.3E+01 Se-79 8.7E+05 Rb-83...

  18. Few-layer MoS2: a promising layered semiconductor.

    PubMed

    Ganatra, Rudren; Zhang, Qing

    2014-05-27

    Due to the recent expanding interest in two-dimensional layered materials, molybdenum disulfide (MoS2) has been receiving much research attention. Having an ultrathin layered structure and an appreciable direct band gap of 1.9 eV in the monolayer regime, few-layer MoS2 has good potential applications in nanoelectronics, optoelectronics, and flexible devices. In addition, the capability of controlling spin and valley degrees of freedom makes it a promising material for spintronic and valleytronic devices. In this review, we attempt to provide an overview of the research relevant to the structural and physical properties, fabrication methods, and electronic devices of few-layer MoS2. Recent developments and advances in studying the material are highlighted. PMID:24660756

  19. VUV photochemistry of oriented molecules: methylchloride on highly oriented pyrolytic graphite

    NASA Astrophysics Data System (ADS)

    Wilkes, J.; Lamont, C. L. A.; Sìller, L.; Coquel, J. M.; Palmer, R. E.

    1997-11-01

    The photoionization of CH 3Cl adsorbed on highly oriented pyrolytic graphite has been investigated as a function of the photon energy in the range 13-35 eV. Two ions were detected — CH +3 and H + — which show differences in their coverage and energy dependences. At very low coverages only H + ions are produced, while at higher coverages (still in the monolayer regime) CH +3 ions are also observed, reflecting a change in the orientation of the molecule on the surface as a function of coverage. The cross-section curves as a function of the photon energy for both ions show a maximum at 22 eV, while the onsets are at 16 eV for CH +3 and 19 eV for H +.

  20. Optical properties of ZnO powder prepared by using a proteic sol-gel process

    NASA Astrophysics Data System (ADS)

    Kwon, Bong-Joon; Woo, Hyun-Joo; Park, Ji-Yeon; Jang, Kiwan; Lim, Seung-Hyuk; Cho, Yong-Hoon

    2013-03-01

    We have studied the optical properties of ZnO powder synthesized by using a proteic sol-gel process with coconut water as the precursor. The energy dispersive X-ray spectrometer and X-ray diffraction results show high purity of the synthesized ZnO powder. From the low-temperature (12 K) and power-dependent PL spectra, the donor-bound exciton, the acceptor-bound exciton, the donor-to-acceptor pair (DAP), and the phonon-replica of the DAP transition have been observed at 3.38, 3.34, 3.26, and 3.19 eV, respectively. The free exciton emission (˜3.3 eV) is also observed at 300 K in the temperature-dependent PL spectra.

  1. Tunable electronic and optical behaviors of two-dimensional germanium carbide

    NASA Astrophysics Data System (ADS)

    Xu, Zhuo; Li, Yangping; Li, Chenxi; Liu, Zhengtang

    2016-03-01

    The electronic and optical properties of two-dimensional graphene-like germanium carbide (2D-GeC) are calculated using first-principle calculation based on density functional theory. Monolayer GeC has a direct band gap of 2.19 eV. The imaginary part of the dielectric function shows a wide energy range of absorption spectrum for monolayer GeC. Tunable band structures are found for monolayer GeC through in-plane strain. In addition, the band structures and optical properties of bilayer GeC under strain along the c axis are analyzed. Multilayer GeC exhibits a direct band gap like monolayer GeC, and new options of interband transitions are found between layers. The results suggest that 2D-GeC could be a good candidate for optoelectronic such as light-emitting diodes, photodiodes, and solar cells.

  2. Growth and depth dependence of visible luminescence in wurtzite InN epilayers

    SciTech Connect

    Pu, X.D.; Shen, W.Z.; Zhang, Z.Q.; Ogawa, H.; Guo, Q.X.

    2006-04-10

    We present detailed investigation of growth and depth dependence of visible ({approx}1.9 eV) photoluminescence (PL) in wurtzite InN epilayers grown by magnetron sputtering. For normal surface incidence, PL peak was found to redshift with increasing growth temperatures. Cross-sectional PL measurements were able to separate contributions from the InN epilayers and sapphire substrates, which not only demonstrated the visible luminescence in InN but also revealed the blueshift of the PL peak with laser spot focusing from epilayer surface toward the interface. The results have been well explained by the growth mechanism and residual strain along growth direction of InN epilayers.

  3. Enteropathogenic Escherichia coli in raw and cooked food.

    PubMed

    Norazah, A; Rahizan, I; Zainuldin, T; Rohani, M Y; Kamel, A G

    1998-03-01

    A total of 402 Escherichia coli isolates were obtained from a variety of food samples and screened for enteropathogenic E. coli (EPEC). Screening was carried out using 15 specific monovalent antisera from Murex Diagnostic Limited. A total of 19 E. coli isolates were serotyped as EPEC. The EPEC strains were shown to belong to 8 serotypes. Eight out of 19 EPEC strains belonged to serotype 018C:K77 (B21). Seventeen out of 19 of the EPEC strains were isolated from cooked food. The presence of E. coli in cooked food is an indicator of fecal contamination and a sign of unhygienic food handling. The presence of EPEC in food could be a potential source of food-borne outbreak. Hygiene training for every food-handler is a necessity. PMID:9740276

  4. DNA sequence analysis of a 10 624 bp fragment of the left arm of chromosome XV from Saccharomyces cerevisiae reveals a RNA binding protein, a mitochondrial protein, two ribosomal proteins and two new open reading frames.

    PubMed

    Lafuente, M J; Gamo, F J; Gancedo, C

    1996-09-01

    We have determined the sequence of a 10624 bp DNA segment located in the left arm of chromosome XV of Saccharomyces cerevisiae. The sequence contains eight open reading frames (ORFs) longer than 100 amino acids. Two of them do not present significant homology with sequences found in the databases. The product of ORF o0553 is identical to the protein encoded by the gene SMF1. Internal to it there is another ORF, o0555 that is apparently expressed. The proteins encoded by ORFs o0559 and o0565 are identical to ribosomal proteins S19.e and L18 respectively. ORF o0550 encodes a protein with an RNA binding signature including RNP motifs and stretches rich in asparagine, glutamine and arginine. PMID:8896268

  5. Correlation of the highest energy cosmic rays with nearby extragalactic objects

    SciTech Connect

    Abraham, J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez, C.; Alvarez-Muniz, J.; Ambrosio, M.; /Balseiro Inst., San Carlos de Bariloche /Buenos Aires, CONICET /CNEA, Buenos Aires /Pierre Auger Observ. /La Plata U. /Natl. Tech. U., San Rafael /Adelaide U. /Catholic U. of Bolivia, La Paz /Bolivia U. /Rio de Janeiro, CBPF /Sao Paulo U.

    2007-11-01

    Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrate that there is a correlation between the arrival directions of cosmic rays with energy above {approx} 6 x 10{sup 19} eV and the positions of active galactic nuclei (AGN) lying within {approx} 75 Mpc. We reject the hypothesis of an isotropic distribution of these cosmic rays at over 99% confidence level from a prescribed a priori test. The correlation we observe is compatible with the hypothesis that the highest energy particles originate from nearby extragalactic sources whose flux has not been significantly reduced by interaction with the cosmic background radiation. AGN or objects having a similar spatial distribution are possible sources.

  6. O/S-1/ interactions - The product channels. [collisional electron quenching and chemical reaction pathway frequencies

    NASA Technical Reports Server (NTRS)

    Slanger, T. G.; Black, G.

    1978-01-01

    The first measurements are reported of the reaction pathways for the interaction between oxygen atoms in the 4.19 eV S-1 state, and four molecules, N2O, CO2, H2O, and NO. Distinction is made between three possible paths - quenching to O(D-1), quenching to O(P-3), and chemical reaction. With N2O, the most reasonable interpretation of the data indicates that there no reaction, in sharp contrast with the interaction between O(D-1) and N2O, which proceeds entirely by reaction. Similarly, there is no reaction with CO2. With H2O, the reactive pathway is the dominant one, although electronic quenching is not negligible. With NO, O(D-1) is the preferred product.

  7. Oxygen-Induced Degradation in C60-Based Organic Solar Cells: Relation Between Film Properties and Device Performance.

    PubMed

    Bastos, João P; Voroshazi, Eszter; Fron, Eduard; Brammertz, Guy; Vangerven, Tim; Van der Auweraer, Mark; Poortmans, Jef; Cheyns, David

    2016-04-20

    Fullerene-based molecules are the archetypical electron-accepting materials for organic photovoltaic devices. A detailed knowledge of the degradation mechanisms that occur in C60 layers will aid in the development of more stable organic solar cells. Here, the impact of storage in air on the optical and electrical properties of C60 is studied in thin films and in devices. Atmospheric exposure induces oxygen-trap states that are 0.19 eV below the LUMO of the fullerene C60. Moreover, oxygen causes a 4-fold decrease of the exciton lifetime in C60 layers, resulting in a 40% drop of short-circuit current from optimized planar heterojunction solar cells. The presence of oxygen-trap states increases the saturation current of the device, resulting in a 20% loss of open-circuit voltage. Design guidelines are outlined to improve air stability for fullerene-containing devices. PMID:27065475

  8. The Surface Detector System of the Pierre Auger Observatory

    SciTech Connect

    Allekotte, I.; Barbosa, A.F.; Bauleo, P.; Bonifazi, C.; Civit, B.; Escobar, C.O.; Garcia, B.; Guedes, G.; Gomez Berisso, M.; Harton, J.L.; Healy, M.; /Cuyo U. /Buenos Aires, CONICET /Natl. Tech. U., San Rafael /Campinas State U. /UEFS, Feira de Santana /Bahia U. /BUAP, Puebla /Santiago de Compostela U. /Fermilab /UCLA /Colorado State U.

    2007-11-01

    The Pierre Auger Observatory is designed to study cosmic rays with energies greater than 10{sup 19} eV. Two sites are envisaged for the observatory, one in each hemisphere, for complete sky coverage. The southern site of the Auger Observatory, now approaching completion in Mendoza, Argentina, features an array of 1600 water-Cherenkov surface detector stations covering 3000 km{sup 2}, together with 24 fluorescence telescopes to record the air shower cascades produced by these particles. The two complementary detector techniques together with the large collecting area form a powerful instrument for these studies. Although construction is not yet complete, the Auger Observatory has been taking data stably since January 2004 and the first physics results are being published. In this paper we describe the design features and technical characteristics of the surface detector stations of the Pierre Auger Observatory.

  9. The JEM-EUSO optics system

    SciTech Connect

    Takizawa, Yoshiyuki; Marchi, Alessandor Zuccaro; Takahashi, Yoshiyuki

    2011-09-22

    The Extreme Universe Space Observatory onboard the Japanese Experiment Module is an international mission devoted to the detection of ultra high-energy cosmic particles with energies E>7x10{sup 19} eV. They are revealed through emission in the atmosphere of Cherenkov and fluorescence light in the near-UV region, by using an optical system with 60 deg. field of view and a 2.3 m entrance pupil. One of the challenges consists in developing an unusual combination of large and lightweight refractive optics: two double-sided curved Fresnel lenses and a central curved Fresnel+diffractive lens, whose maximum dimensions are 2.65 m. This paper describes the development of such a optical system and its performances of the latest configurations.

  10. Exploring Mbar shock conditions and isochorically heated aluminum at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (invited)

    SciTech Connect

    Fletcher, L. B.; Lee, H. J.; Gauthier, M.; Galtier, E.; Nagler, B.; Heimann, P.; Hastings, J. B.; Glenzer, S. H.; Barbrel, B.; Falcone, R. W.; Döppner, T.; LePape, S.; Ma, T.; Pak, A.; Turnbull, D.; White, T.; Gregori, G.; Wei, M.; Zastrau, U.

    2014-11-15

    Recent experiments performed at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatter x-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using velocity interferometer system for any reflector have been measured. The combination of experiments fully demonstrates the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.

  11. High prevalence and variability of CTX-M-15-producing and fluoroquinolone-resistant Escherichia coli observed in stray dogs in rural Angola.

    PubMed

    Albrechtova, Katerina; Kubelova, Michaela; Mazancova, Jana; Dolejska, Monika; Literak, Ivan; Cizek, Alois

    2014-08-01

    Antimicrobial resistance (AMR) represents a serious problem globally, but it is especially pronounced in the tropics, where pressure of infectious diseases is high. We examined resistance in Escherichia coli colonizing gastrointestinal tracts of 17 dogs which have never received antimicrobial treatment, living in central rural Angola. Emphasis was placed on extended-spectrum beta-lactamases (ESBL) and plasmid-mediated quinolone resistance (PMQR). Resistance-carrying plasmids were characterized in size, group of incompatibility and ability to conjugate. Isolates were compared by their pulsed-field gel electrophoresis (PFGE) profiles. Detailed description of 19 E. coli isolates with either ESBL or PMQR genes carried on multiresistant plasmids of different groups of incompatibility indicates that dogs, despite never being treated by antibiotics, are important reservoirs and transmitters of AMR in the study area. PMID:24568119

  12. Study of Travelling Interplanetary Phenomena (STIP) workshop travel

    NASA Technical Reports Server (NTRS)

    Wu, S. T.

    1986-01-01

    Thirty six abstracts are provided from the SCOSTEP/STIP Symposium on Retrospective Analyses and Future Coordinated Intervals held in Switzerland on June 10 to 12, 1985. Six American scientists participated in the symposium and their abstracts are also included. The titles of their papers are: (1) An analysis of near surface and coronal activity during STIP interval 12, by T. E. Gergely; (2) Helios images of STIP intervals 6, B. V. Jackson; (3) Results from the analysis of solar and interplanetary observations during STIP interval 7, S. R. Kane; (4) STIP interval 19, E. Cliver; (5) Hydrodynamic buoyancy force in the solar atmosphere, T. Yeh; and (6) A combined MHD modes for the energy and momentum transport from solar surface to interplanetary space, S. T. Wu.

  13. Robust red-emission spectra and yields in firefly bioluminescence against temperature changes

    NASA Astrophysics Data System (ADS)

    Mochizuki, Toshimitsu; Wang, Yu; Hiyama, Miyabi; Akiyama, Hidefumi

    2014-05-01

    We measured the quantitative spectra of firefly (Photinus pyralis) bioluminescence at various temperatures to investigate the temperature dependence of the luciferin-luciferase reaction at 15-34 °C. The quantitative spectra were decomposed very well into red (1.9 eV), orange (2.0 eV), and green (2.2 eV) Gaussian components. The intensity of the green component was the only temperature sensitive quantity that linearly decreased as the temperature increased at pH 7 and 8. We found the quantitative bioluminescence spectra to be robust below 2.0 eV against temperature and other experimental conditions. The revealed robustness of the red emissions should be useful for quantitative applications such as adenosine-5'-triphosphate detection.

  14. Events associated with restoration by zinc of meiosis in apomictic Saccharomyces cerevisiae.

    PubMed Central

    Bilinski, C A; Miller, J J; Girvitz, S C

    1983-01-01

    The effects of nutritional alterations (carbon source and zinc) on nuclear division and protein synthesis during apomictic and meiotic development in Saccharomyces cerevisiae 19e1 were investigated. Unlike cells cultivated under meiosis-promoting conditions, cells cultured under apomixis-promoting conditions exhibited extensive protein synthesis during the first 3 h of incubation in sporulation medium, and nuclear divisions were evident during this time. Cycloheximide treatment of the latter cells induced meiosis, and maximum yields of meiotic asci resulted when this treatment was given for the first 3 h in sporulation medium. The results indicate that the decision concerning which developmental route cells will follow is made shortly after transfer to sporulation medium. Electrophoretic analysis of labeled proteins synthesized during sporulation revealed bands unique to both developmental routes. Images PMID:6350265

  15. In-situ characterization of growth and interfaces in a-Si:H devices. Final subcontract report, 1 May 1991--31 May 1994

    SciTech Connect

    Collins, R.W.; Wronski, C.R.; An, I.; Lu, Y.; Nguyen, H.V.

    1994-07-01

    This report describes work to identify materials parameters that can quantitatively describe the solar cell performance correctly in the initial and stabilized states and are consistent with a microscopic model of the metastable defect site. The objective is to be accomplished by applying results of in-situ analyses of a-Si:H surfaces and the transparent conducting oxide (TCO)/p/i interfaces to complement the present understanding of the electronic properties of materials and devices. A second objective of the program is to demonstrate, characterize, and understand improved doped and undoped ``wide-gap`` materials for use in achieving 15% stabilized photovoltaic modules (``wide-gap`` materials are defined as those materials with a band gap of at least 1.9 eV).

  16. Antireflux versus conventional self-expanding metallic Stents (SEMS) for distal esophageal cancer: results of a multicenter randomized trial

    PubMed Central

    Coron, E.; David, G.; Lecleire, S.; Jacques, J.; Le Sidaner, A.; Barrioz, T.; Coumaros, D.; Volteau, C.; Vedrenne, B.; Bichard, P.; Boustière, C.; Touchefeu, Y.; Brégeon, J.; Prat, F.; Le Rhun, M.

    2016-01-01

    Introduction: Self-expanding metal stents (SEMS) are commonly used in the palliation of dysphagia in patients with inoperable esophageal carcinoma. However, they predispose to gastroesophageal reflux when deployed across the gastroesophageal junction. The aims of this study were to: 1) assess the influence of the antireflux valve on trans-prosthetic reflux (primary outcome); and 2) compare the results of SEMS with and without antireflux valve in terms of reflux symptoms, quality of life (QOL), improvement of dysphagia and adverse events (secondary outcomes). Patients and methods: Thirty-eight patients were enrolled in nine centers. Carcinomas were locally advanced (47 %) or metastatic. After randomization, patients received either a covered SEMS with antireflux valve (n = 20) or a similar type of SEMS with no antireflux device but assigned to standard proton pump inhibitor therapy and postural advice (n = 18). Trans-prosthetic reflux was assessed at day 2 using a radiological score based on barium esophagography performed after Trendelenburg maneuver and graded from 0 (no reflux) to 12 (maximum). Monthly telephone interviews were conducted for Organisation Mondiale de la Santé (OMS) scoring from 0 (excellent) to 5 (poor), QOL assessment (based on the Reflux-Qual Simplifié scoring system) from 0 (poor) to 100 (excellent), dysphagia scoring from 0 (no dysphagia) to 5 (complete dysphagia) and regurgitation scoring from 0 (no regurgitation) to 16 (maximum). Results: No difference was noted in terms of age, sex, size of lesion, prosthesis length or need for dilation prior to SEMS placement. No difficulty in placing SEMS nor complications were noted. Radiological scores of reflux were found to be significantly lower in patients with an antireflux stent compared to the conventional stent and associated measures. The regurgitation scores were significantly decreased in patients with antireflux stents during the first 2 months after stent placement and

  17. Une version québécoise du Sport Concussion Assessment Tool 2 (SCAT2)—Outil d'évaluation des commotions cérébrales dans le sport 2 : Québec (SCAT2-Qc)

    PubMed Central

    Boyd, Jami; Boyer-Rémillard, Marie-Eve; Pilon-Piquette, Michael; McKinley, Patricia

    2013-01-01

    RÉSUMÉ Objectif : traduire le Sport Concussion Assessment Tool 2 (SCAT2) dans la langue française parlée au Québec et en vérifier l'acceptabilité pour la population québécoise francophone. Méthodologie : le processus de traduction de la version originale du SCAT2 a fait appel à une variante de la méthode de traduction et d'adaptation d'outils proposée par l'Organisation mondiale de la santé. Une traduction parallèle a d'abord été réalisée. Ensuite, un comité a révisé cette traduction parallèle dans le but de produire une version préliminaire du SCAT2-Qc. Puis, on a procédé à une rétrotraduction parallèle, que l'on a comparée à la version originale. La version préliminaire a été modifiée. Pour parvenir à la version finale, on a intégré les suggestions et les commentaires formulés par deux sujets sains lors de l'essai de l'outil, et lors de la comparaison du SCAT2-Qc à la version française existante par trois réviseurs du domaine de la santé. On a ensuite testé la version finale du SCAT2-Qc auprès de douze sujets sains pour en vérifier l'acceptabilité. Résultats : les douze sujets sains n'ont eu aucun problème de compréhension en utilisant le SCAT2-Qc. Conclusion : les différentes étapes de traduction ont permis de créer le SCAT2-Qc. Son contenu ayant été validé, il peut à présent être utilisé dans le milieu sportif et scientifique québécois. PMID:24396168

  18. Une étude cas-témoins pour déterminer les facteurs de non-observance du suivi médical chez les patients diabétiques à Kinshasa, en 2010

    PubMed Central

    Mense, Kennedy; Mapatano, Mala Ali; Mutombo, Paulin Beya; Muyer, Marie Claire

    2014-01-01

    Introduction Le diabète est un problème majeur de santé publique et un fardeau économique mondial qui n’épargne pas la RD-Congo. Bien que sa prise en charge soit codifiée, la plupart des diabétiques n'arrivent pas à respecter les rendez-vous de suivi. Cette étude vise principalement à identifier les déterminants de la non-observance du suivi médical chez les diabétiques à Kinshasa. Méthodes Il s'agit d'une étude cas-témoins où les cas sont les patients diabétiques non observant le suivi médical et les témoins, ceux répondant régulièrement au suivi médical. Couvrant la période du 1erjanvier au 31 décembre 2010, l’étude a porté sur un échantillon aléatoire de 154 sujets répartis entre 77 cas et 77 témoins. Résultats Les données indiquent une association entre la non-observance du suivi médical et le revenu (niveau de vie) des ménages. Les cas provenant des ménages à faible revenu courent six fois plus le risque d’être non-observants. Par contre, entre le niveau de connaissance et la non-observance l'association notée n’était pas statistiquement significative. Le respect des rendez-vous pourrait être amélioré de 77% si le revenu des ménages des diabétiques était augmenté. Le coût total mensuel du suivi médical est estimé à 27,2 USD, alors que le revenu permanant des ménages se situe à 306,6 USD. Conclusion Le bas niveau de vie mais pas celui de l'ignorance est un déterminant de la non-observance des visites de suivi du malade diabétique. PMID:25309658

  19. Clinical practice guideline: management of acute pancreatitis

    PubMed Central

    Greenberg, Joshua A.; Hsu, Jonathan; Bawazeer, Mohammad; Marshall, John; Friedrich, Jan O.; Nathens, Avery; Coburn, Natalie; May, Gary R.; Pearsall, Emily; McLeod, Robin S.

    2016-01-01

    There has been an increase in the incidence of acute pancreatitis reported worldwide. Despite improvements in access to care, imaging and interventional techniques, acute pancreatitis continues to be associated with significant morbidity and mortality. Despite the availability of clinical practice guidelines for the management of acute pancreatitis, recent studies auditing the clinical management of the condition have shown important areas of noncompliance with evidence-based recommendations. This underscores the importance of creating understandable and implementable recommendations for the diagnosis and management of acute pancreatitis. The purpose of the present guideline is to provide evidence-based recommendations for the management of both mild and severe acute pancreatitis as well as the management of complications of acute pancreatitis and of gall stone–induced pancreatitis. Une hausse de l’incidence de pancréatite aiguë a été constatée à l’échelle mondiale. Malgré l’amélioration de l’accès aux soins et aux techniques d’imagerie et d’intervention, la pancréatite aiguë est toujours associée à une morbidité et une mortalité importantes. Bien qu’il existe des guides de pratique clinique pour la prise en charge de la pancréatite aiguë, des études récentes sur la vérification de la prise en charge clinique de cette affection révèlent des lacunes importantes dans la conformité aux recommandations fondées sur des données probantes. Ces résultats mettent en relief l’importance de formuler des recommandations compréhensibles et applicables pour le diagnostic et la prise en charge de la pancréatite aiguë. La présente ligne directrice vise à fournir des recommandations fondées sur des données probantes pour la prise en charge de la pancréatite aiguë, qu’elle soit bénigne ou grave, ainsi que de ses complications et de celles de la pancréatite causée par un calcul biliaire. PMID:27007094

  20. Digital HF communications for the polar regions - a low-cost alternative to satellite?

    NASA Astrophysics Data System (ADS)

    Prior-Jones, Michael; Warrington, Mike

    2010-05-01

    Digital HF communications for the polar regions - a low-cost alternative to satellite? Prior-Jones, M.R. and Warrington, E. M Communications within the polar regions pose unique technical challenges, due to the physical isolation, lack of infrastructure and extreme weather conditions. Geostationary satellite links are widely used, but they cannot function poleward of 80 degrees due to the curvature of the Earth. Low-earth-orbit systems like Iridium and ARGOS will function all the way to the poles. However, they are expensive, particularly for experiments requiring long time-series. Transferring data by Iridium satellite phone costs of the order of 60USD per megabyte. HF (i.e. 3-30 MHz) radio signals propagate via the ionosphere, allowing long distance transmission beyond the horizon. Ranges of thousands of kilometres can be easily achieved with relatively low transmission powers when propagation is favourable. The polar ionosphere is, however, a challenging environment for radio signals - the signals often reflect from multiple regions of the ionosphere and by multiple hops with intermediate ground reflections producing multipath effects. As the ionosphere is moving, these signals are also subject to very significant Doppler shifts that add to the complexity of the environment. These effects may make data communications at polar latitudes difficult or impossible at times and often only at low data rates. In this paper we discuss our experiments to use modern signal-processing and modulation techniques for digital transmission on HF, offering a similar speed to satellite but without paying the high cost of satellite airtime. Using an HF channel simulator developed by Warrington et al based on measurements of propagation at high latitudes, we have tested the performance of an OFDM-based modem derived from the Digital Radio Mondiale standard used for digital HF broadcasting and found that it outperforms current military modems developed by NATO (STANAG 4285 and 4539

  1. Profil épidémiologique de l'infection à VIH au cours d'une campagne de sensibilisation à Yaoundé au Cameroun

    PubMed Central

    Mbopi-Keou, Francois-Xavier; Nguefack-Tsague, Georges; Kalla, Ginette Claude Mireille; Viche, Lade; Noubom, Michel

    2013-01-01

    Introduction L'objectif de ce travail était de déterminer le profil épidémiologique de l'infection à VIH/SIDA au cours d'une campagne de sensibilisation à Yaoundé au Cameroun. Méthodes Après avoir obtenu le consentement éclairé des participants, le dépistage de l'infection par le VIH a été effectué selon l'algorithme de dépistage en série de l'Organisation Mondiale de la Santé (OMS). En outre, un questionnaire socio-comportemental a été proposé à chaque participant. Résultats Au total, 911 personnes ont été dépistées. La prévalence de l'infection par le VIH était de 2.6%. Elle était 3 fois plus élevée parmi les femmes (RC = 3.22, IC (1.26 - 8.18). Les prévalences les plus élevées ont été observées chez les personnes de plus de 45 ans (p = 0.01), les personnes sans emploi (p < 0.001) et les veufs/veuves (p = 0.02). Plus de 80% des participants trouvaient le test de dépistage nécessaire et 76,2% l'avaient déjà effectué au moins une fois auparavant. Il s'agissait principalement de femmes (p = 0.02), d'étudiants (p < 0.001) et des personnes âgées de 25 à 34 ans (p < 0.001). Les personnes séropositives avaient moins tendance à retirer leur résultat (p = 0.01). Conclusion Il apparait urgent d'intensifier les campagnes de dépistage de l'infection par le VIH en ciblant davantage des groupes particuliers tels que les élèves, les personnes âgées et les veufs/veuves, tout en recherchant les facteurs pouvant favoriser la propagation de l'infection dans ces groupes. PMID:24255725

  2. Diabète en milieu urbain de Ouagadougou au Burkina Faso: profil épidémiologique et niveau de perception de la population adulte

    PubMed Central

    Millogo, Georges Rosario Christian; Yaméogo, Clément; Samandoulougou, André; Yaméogo, Nobila Valentin; Kologo, Koudougou Jonas; Toguyeni, Jean Yves; Zabsonré, Patrice

    2015-01-01

    Introduction L'accroissement rapide de la prévalence du diabète sucré en Afrique subsaharienne constitue un problème de santé public. L'Organisation Mondiale de la Santé (OMS) estime qu’à l'horizon 2025, l'augmentation la plus significative de la prévalence du diabète sera enregistrée dans les pays en développement. Ceux-ci devraient abriter 75% des patients diabétiques du monde. Outre ses complications métaboliques, le diabète est un facteur de risque cardiovasculaire majeur. Le but de notre étude était de decrire le profil épidémiologique du diabète et d’évaluer le niveau de perception de la maladie par une population africaine en milieu urb qwqain de Ouagadougou. Méthodes Le diabète a été défini chez tout sujet ayant une glycémie casuelle supérieure à 2 g/L ou une glycémie à jeun supérieur ou égale à 1,26 g/L (≥ 7 mmol/L) à deux controles d'une semaine d'intervalle. Etaient considérés diabétique, les sujets déjà suivis et ceux nouvellement dépistés par l'etude. Résultats L’étude a inclus 1532 personnes, d’âge compris entre 25 et 64 ans dont 55,6% d'hommes et 44,4% de femmes. L’âge moyen était 36,10 ± 11,19 ans. La tranche d’âge de 25 à 34 ans était la plus représentée avec une proportion de 57,1%. La glycémie moyenne était de 1,04 g/L, la proportion des femmes ayant une hyperglycémie était statistiquement plus importante que celle des hommes (p< 0,05). Près de 81,3% de la population ignoraient que le diabète était un facteur de risque cardiovasculaire. Conclusion Il est urgent de mettre en place un programme national de lutte contre le diabète sucré et les autres maladies non transmissibles au Burkina Faso. PMID:26524982

  3. Surpoids et obésité dans la population générale de 5 à 19 ans en milieu urbain bamakois (Mali)

    PubMed Central

    Oumar Bâ, Hamidou; Menta, Ichaka; Camara, Youssouf; Doumbia, Plutôt Seydou; Diarra, Mamadou Bocary

    2014-01-01

    Introduction Déterminer la prévalence du surpoids et de l'obésité dans la population âgée de 5 à 19 ans et fournir des données de référence pour de futures études. Méthodes Notre échantillon est issu de la première étude sur les pathologies cardiovasculaires basée sur l'approche STEP de l'Organisation Mondiale de la Santé (OMS) en sélectionnant tous les sujets âgés de 5 à 19 ans. Nous avons utilisé les méthodes de l'OMS et de l'International Obesity Task Force (IOTF) pour déterminer la prévalence du surpoids et de l'obésité dans la population générale. Résultats La moyenne d’âge était de 11,75 ans ± 4,387 et le sex-ratio M:F était de 0,79. les moyennes pour le poids et la taille étaient de 36,85 kg et 143,48 cm. Selon les critères OMS 1,61% des garçons et 3,28% des filles étaient en surpoids et 0,92% des garçons contre 1,46% des filles obèses. Selon les critères de l'IOTF 4,10% des garçons et 5,94% des filles étaient en surpoids tandis que 0,72% des garçons et 2,68% des filles étaient obèses. Conclusion Malgré sa faible prévalence le surpoids et l'obésité doivent être régulièrement étudiés pour reconnaître des tendances et prendre des mesures adéquates de prévention. Les 2 méthodes utilisées ont permis d'avoir des données de référence pour de futures études au Mali et ailleurs. PMID:25932064

  4. Résultats fonctionnels de la chirurgie de la cataracte par phacoalternative avec implantation en chambre postérieure: à propos de 300 cas à Bobo Dioulasso (Burkina Faso)

    PubMed Central

    Diallo, Jean Wenceslas; Meda, Nonfounikoun; Ahnoux-Zabsonre, Ahgbatouhabéba; Yameogo, Claudette; Dolo, Mariam; Sanou, Jérôme; Daboue, Arsène

    2015-01-01

    La cataracte est la première cause de cécité curable dans le monde. Son traitement est chirurgical. Le but de notre travail a été d’évaluer les résultats de la phacoalternative ou la chirurgie de la cataracte à petite incision. Il s'est agi d'une étude transversale descriptive à collecte prospective allant du 1er janvier au 31 septembre 2014, chez des patients âgés d'au moins 40 ans. Les données socio-démographiques, l'acuité visuelle, l'astigmatisme et les complications ont été évalués. Nous avons inclus 300 yeux de 286 patients. L’âge moyen était de 66 ans (écart type 9,93) avec une prédominance masculine de 57,7%. Les co-morbidités étaient dominées par l'hypertension artérielle 30,33% des cas. L'acuité visuelle pré-opératoire était de moins de 1/20è dans 70, 7% des cas. En biométrie, la puissance moyenne était de 21,50 dioptries. L'implant posé a été adéquat dans 60%. Les principales complications per-opératoires étaient le chémosis post-anesthésie 4,67% et l'issue de vitrée moins de 2% des cas. Les complications post opératoires précoces ont été dominées par l’œdème de cornée 26,33%, et les complications tardives par la cataracte secondaire. L'astigmatisme induit était de 1, 12 dioptrie en moyenne (écart type 1,26). Sans correction, les résultats visuels étaient mauvais dans moins de 1%, limites dans 31%, et bons 68% suivants les normes de l'Organisation Mondiale de la Santé. La phacoalternative donne des résultats satisfaisants, avec peu de complications. L'amélioration du plateau technique et la disponibilité d'implants adéquats pourraient les améliorer. PMID:26140073

  5. 5 A, version modifée

    PubMed Central

    Vallis, Michael; Piccinini-Vallis, Helena; Sharma, Arya M.; Freedhoff, Yoni

    2013-01-01

    Objectif Adapter le modèle 5 A pour offrir aux professionnels des soins primaires un cadre de counseling sur l'obésité. Sources des données Une recension systématique des ouvrages spécialisés a été effectuée dans MEDLINE à l'aide des expressions de recherche 5 A's (49 articles recensés, tous pertinents) et 5 A's et primary care (8 articles recensés, tous redondants). On a aussi fait une recherche dans les sites web du National Institute of Health et de l'Organisation mondiale de la Santé. Message principal L'approche 5 A (autorisation, analyse, avis, accord et aide ou ask, assess, advise, agree et assist en anglais), élaborée pour la cessation du tabagisme, peut être adaptée au counseling sur l'obésité. Demander l'autorisation de discuter du poids; ne pas porter de jugement et explorer la volonté du patient de changer. Analyser l'indice de masse corporelle, la circonférence de la taille et le stade de l'obésité; explorer les déclencheurs et les complications de l'excès de poids. Donner son avis sur les risques de l'obésité pour la santé, les bienfaits d'une modeste perte de poids, la nécessité d'une stratégie à long terme et les options de traitements. Se mettre d'accord sur des attentes, des objectifs et des changements comportementaux réalistes pour perdre du poids et sur les détails précis du plan de traitement. Assister dans l'identifcation et l'atténuation des obstacles; offrir des ressources, aider à trouver et à consulter les services appropriés et organiser un suivi périodique. Conclusion Les 5 A représentent une stratégie d'intervention comportementale fondée sur des données probantes qui a le potentiel d'améliorer le taux de réussite de la gestion du poids en soins primaires.

  6. Epidémiologie de l'infection à Helicobacter Pylori à Yaoundé: de la particularité à l’énigme Africaine

    PubMed Central

    Andoulo, Firmin Ankouane; Noah, Dominique Noah; Tagni-Sartre, Michèle; Ndam, Elie Claude Ndjitoyap; Blackett, Katleen Ngu

    2013-01-01

    Introduction L'infection à Hélicobacter pylori concerne la moitié de la population mondiale, principalement dans les pays en voie de développement où l'infection atteint 80% de la population. Le but de notre étude était de déterminer la prévalence de l'infection à Hélicobacter pylori et de mettre en évidence les déterminants de l'infection ainsi que les maladies associées au Cameroun. Méthodes L’étude concernait 171 sujets symptomatiques référés pour une fibroscopie œsogastroduodénale au Centre Hospitalier et Universitaire de Yaoundé et au Centre Médical la Cathédrale. L'infection à H.pylori était objectivée par un test rapide à l'uréase kit commercial Pronto Dry® (Medical Instruments Corporation, Solothurn, Switzerland). Résultats La prévalence globale de l'infection à Hélicobacter pylori était de 72,5% (124/171) (Intervalle de Confiance (IC) à 95% 65,2-79,1%) et dans chaque groupe d’âge (moins de 40ans, 40-50ans, plus de 50ans) de 83,1%(64/77), 67,4%(29/43) et 60,8%(31/51) respectivement. En analyse univariée, le risque de l'infection était significativement élevé dans le groupe de moins de 40ans comparé au groupe de 40-50ans (Risque Relatif (RR) 0,42 IC 95% 0,16-1,1, p = 0,04 pour le groupe 40-50ans) et comparé au groupe de plus de 50ans (RR 0,73; 0,57-0,93, p = 0,004 pour le groupe de plus de 50ans). La prévalence de l'infection à H.pylori était de 63,0% (17/27) pour l'ulcère duodénal, 50%(4/8) pour l'ulcère gastrique et 100%(2/2) pour le cancer gastrique. Conclusion A prévalence de l'infection à H.pylori au Cameroun est très élevée et significativement liée à l’âge de moins de 40 ans. PMID:24778752

  7. Lait humain provenant d’une banque de dons ou acheté en ligne?

    PubMed Central

    St-Onge, Maude; Chaudhry, Shahnaz; Koren, Gideon

    2015-01-01

    Résumé Question Une de mes patientes m’a demandé si elle pourrait se procurer du lait humain par Internet pour allaiter son nourrisson s’il le fallait. L’usage de lait humain provenant d’une banque de dons est-il plus sécuritaire que son achat en ligne? Réponse L’Organisation mondiale de la Santé et l’American Academy of Pediatrics recommandent d’utiliser des dons de lait humain comme choix à privilégier lorsque le lait maternel n’est pas disponible. Cependant, la Société canadienne de pédiatrie n’approuve pas le partage de lait humain non traité. Le lait humain entreposé dans les banques de lait diffère de celui qu’on peut se procurer par Internet en raison du processus rigoureux de sélection des donneuses, des fréquentes inspections de la qualité, des procédés de transport règlementés et du processus de pasteurisation conforme aux directives établies par l’Agence canadienne d’inspection des aliments. La plupart des échantillons achetés en ligne contiennent des bactéries à gram négatif ou comptent au total plus de 104 unités formant colonies de bactéries aérobiques par millilitre; ils renferment aussi en moyenne au décompte total plus de bactéries aérobiques, de bactéries à gram négatif, de coliformes et de Staphylococcus spp que les échantillons des banques de lait. La croissance de la plupart des espèces de bactéries est associée au nombre de jours en transit, ce qui porte à croire que les conditions de collecte, d’entreposage et de transport sont médiocres pour le lait acheté en ligne.

  8. La supraconductivité a 100 ans !

    ScienceCinema

    None

    2011-10-06

    Il y a 100 ans, le 8 avril 1911, une découverte majeure était réalisée : celle de la supraconductivité. La supraconductivité est la caractéristique qu?ont certains métaux et alliages de perdre toute résistance électrique en dessous d?une température donnée. Cette renversante découverte, réalisée de manière presque fortuite par Kammerlingh Onnes de l?Université de Leyde (Pays-Bas) et son étudiant Gilles Holst, a ouvert un nouveau champ de recherche en physique et de fabuleuses perspectives d?applications technologiques. Du point de vue scientifique, la supraconductivité est en effet l?une des rares manifestations de la physique quantique à l?échelle macroscopique.  Du point de vue des retombées techniques, elle est porteuse d?applications majeures dans le domaine de la santé, des communications et de l?énergie. 100 ans après, les physiciens n?ont toujours pas fini d?explorer ce phénomène et ses applications. Le CERN abrite des applications de la supraconductivité à des échelles inédites. L?accélérateur de particules LHC, avec ses milliers d?aimants supraconducteurs répartis sur 27 kilomètres de circonférence, est en effet la plus grande application mondiale de la supraconductivité. Il ne pourrait exister sans elle.  Le CERN fête donc la découverte de la supraconductivité avec une conférence exceptionnelle donnée par Philippe Lebrun. Au cours de cette conférence, l?expérience historique de Kammerlingh Onnes sera reproduite. Philippe Lebrun racontera l?histoire de cette étonnante découverte, en la replaçant dans le contexte scientifique de l?époque. Il racontera les développements scientifiques et les applications du premier siècle de la supraconductivité. Conférence en français Merci de bien vouloir vous inscrire au : +41 22 767 76 76 ou cern.reception@cern.ch

  9. Profil clinique et bactériologique des infections néonatales bactériennes à l'Hôpital Laquintinie de Douala, Cameroun

    PubMed Central

    Kemeze, Sandrine; Moudze, Béatrice; Chiabi, Andreas; Eposse, Charlotte; Kaya, Alexis; Mbangue, Madeleine; Guifo, Odette; Kago, Innocent

    2016-01-01

    Introduction L'Organisation Mondiale de la Santé a estimé la survenue globale de décès néonatal à 2,8 millions en 2015, dont 47,6% étaient dues aux infections. Ces infections peuvent survenir chez un nouveau-né de 0 à un mois de vie, pouvant aller jusqu’à 3 mois. Méthodes C'est une étude prospective allant du 1er mars au 30 juin 2015 au Service de néonatologie de l'Hôpital Laquintinie de Douala. Etaient inclus tout nouveau-né symptomatique avec ou sans critère anamnestique et tout nouveau-né asymptomatique, présentant au moins un risque infectieux et ayant au moins une culture positive ou une anomalie de la numération formule sanguine ou une protéine C réactive positive. Résultats Des 310 nouveau-nés admis, 300 ont été retenus pour infection néonatale, soit une incidence de 96,8%. Nous avons réalisé 104 cultures dont 25 positives, soit une incidence de l'infection néonatale confirmée de 24%. Les facteurs associés à l'infection étaient la prématurité inexpliquée <35 semaines d'aménorrhée(45,1%) et la réanimation néonatale (34,8%). La fièvre (56%) et les troubles neurologiques (48,8%) étaient les manifestations cliniques les plus fréquentes. Les Gram négatifs étaient les germes les plus fréquents (56%). L'imipenème (95%) et l'amikacine (66,7%) étaient les antibiotiques les plusefficaces. L’évolution était favorable dans 66,4% des cas et le taux de décès était de 33,6%. Conclusion Cette étude révèle une forte prévalence de l'infection dans cet hôpital. L’écologie bactérienne est dominée par les Gram négatifs, on note une importante résistance aux antibiotiques usuels et une mortalité assez élevée. PMID:27222688

  10. Clinical importance and representation of toxigenic and non-toxigenic Clostridium difficile cultivated from stool samples of hospitalized patients

    PubMed Central

    Predrag, Stojanovic; Branislava, Kocic; Miodrag, Stojanovic; Biljana, Miljkovic – Selimovic; Suzana, Tasic; Natasa, Miladinovic – Tasic; Tatjana, Babic

    2012-01-01

    The aim of this study was to fortify the clinical importance and representation of toxigenic and non-toxigenic Clostridium difficile isolated from stool samples of hospitalized patients. This survey included 80 hospitalized patients with diarrhea and positive findings of Clostridium difficile in stool samples, and 100 hospitalized patients with formed stool as a control group. Bacteriological examination of a stool samples was conducted using standard microbiological methods. Stool sample were inoculated directly on nutrient media for bacterial cultivation (blood agar using 5% sheep blood, Endo agar, selective Salmonella Shigella agar, Selenite-F broth, CIN agar and Skirrow’s medium), and to selective cycloserine-cefoxitin-fructose agar (CCFA) (Biomedics, Parg qe tehnicologico, Madrid, Spain) for isolation of Clostridium difficile. Clostridium difficile toxin was detected by ELISA-ridascreen Clostridium difficile Toxin A/B (R-Biopharm AG, Germany) and ColorPAC ToxinA test (Becton Dickinson, USA). Examination of stool specimens for the presence of parasites (causing diarrhea) was done using standard methods (conventional microscopy), commercial concentration test Paraprep S Gold kit (Dia Mondial, France) and RIDA®QUICK Cryptosporidium/Giardia Combi test (R-Biopharm AG, Germany). Examination of stool specimens for the presence of fungi (causing diarrhea) was performed by standard methods. All stool samples positive for Clostridium difficile were tested for Rota, Noro, Astro and Adeno viruses by ELISA – ridascreen (R-Biopharm AG, Germany). In this research we isolated 99 Clostridium difficile strains from 116 stool samples of 80 hospitalized patients with diarrhea. The 53 (66.25%) of patients with diarrhea were positive for toxins A and B, one (1.25%) were positive for only toxin B. Non-toxigenic Clostridium difficile isolated from samples of 26 (32.5%) patients. However, other pathogenic microorganisms of intestinal tract cultivated from samples of 16 patients

  11. Structure-activity relationship analysis of the peptide deformylase inhibitor 5-bromo-1H-indole-3-acetohydroxamic acid.

    PubMed

    Petit, Sylvain; Duroc, Yann; Larue, Valéry; Giglione, Carmela; Léon, Carole; Soulama, Coralie; Denis, Alexis; Dardel, Frédéric; Meinnel, Thierry; Artaud, Isabelle

    2009-02-01

    The lead compound 5-bromoindolyl-3-acetohydroxamic acid (10) was recently identified as a potent inhibitor of bacterial peptide deformylases (PDFs). The synthesis and associated activities of new variants were investigated at position 5 to optimize the fit at the S1' subsite and at position 1 to improve both potency and antibacterial activity. A morphomimetic series, termed "reverse-indole" was synthesized. The indole derivatives remain selective in vitro inhibitors of PDF2 over PDF1. Bromide is the best group at position 5 and cannot be replaced by bulkier substituents. In this series, an N-benzyl group at position 1 in 19 e improves the potency relative to 10. In the case of PDF1, and unlike PDF2, potency is increased as the alkyl chain becomes longer and more ramified. These data support the results of NMR footprinting experiments that were performed with (15)N-labeled Ni-PDF and the corresponding 3-acetic acid derivatives. Most of the compounds have antibacterial activities toward B. subtilis, but are inefficient toward E. coli owing to active removal by the major efflux pumps. Among the reverse-indole derivatives, 23 c, which is the exact mirror image of 19 e, shows strong potency in vitro against PDF2, but little against PDF1, although this compound displays significant antibacterial activity toward an efflux-minus mutant of E. coli. All the compounds were assessed with major pathogenic bacteria, but most of them are inefficient antibacterial agents. The reverse-indole compounds 23 a and 23 c have potency against S. pneumoniae that is similar to that of actinonin. PMID:19053131

  12. Research on stable, high-efficiency amorphous silicon multijunction modules

    SciTech Connect

    Bhat, P.K.; Brown, S.; Hollingsworth, R.; Shen, D.S.; del Cueto, J.; Iwanicko, E.; Marshall, C.; DeHart, C.; Mentor, D.; Benson, A.; Matovich, C.; Sandwisch, J. )

    1991-04-01

    This report describes a contract to produce multijunction modules based entirely on amorphous silicon alloys, the modules having an aperture area of at least 900 cm{sup 2} and a stable, reproducible conversion efficiency of at least 6.5% after 600 hours of light exposure (air mass 1.5) at 50{degrees} C. The work focussed on (1) producing opto-electronic-grade amorphous silicon material for band gaps of about 1.7 and 1.9 eV by changing the hydrogen content in the film bonded to the silicon, (2) studying and obtaining data on the light stability of single-junction p-i-n solar cells with gaps of about 1.7 and 1.9 eV, and (3) analyzing losses in a silicon/silicon multijunction cell. We report new results on an indium tin oxide (ITO)/silver back contact and the deposition of granular tin oxide by atmospheric-pressure chemical vapor deposition. Progress toward module fabrication at the end of six months has been good, with the demonstration of 5.4% initial efficiency in a silicon/silicon multijunction submodule with an aperture area of 4620 cm{sup 2} and incorporating devices with 2nd-junction i-layer thicknesses of about 3500 {angstrom}. We also demonstrated a single-junction silicon submodule with an aperture area of 4620 cm{sup 2}, a thickness of about 3500 {angstrom}, and an initial efficiency of 6.5%. 4 refs., 39 figs., 5 tabs.

  13. Point defect study of CuTi and CuTi sub 2

    SciTech Connect

    Shoemaker, J.R.; Lutton, R.T.; Wesley, D.; Wharton, W.R.; Oehrli, M.L.; Herte, M.S.; Sabochick, M.J. ); Lam, N.Q. )

    1991-03-01

    The energies and configurations of interstitials and vacancies in the ordered compounds CuTi and CuTi{sub 2} were determined using atomistic simulation with realistic embedded-atom potentials. The formation energy of an antisite pair was found to be 0.385 and 0.460 eV in CuTi and CuTi{sub 2}, respectively. In both compounds, the creation of a vacancy by the removal of either a Cu or Ti atom resulted in a vacant Cu site, with an adjacent antisite defect in the case of the Ti vacancy. The vacant Cu site in CuTi was found to be very mobile within two adjacent (001) Cu planes, with a migration energy of 0.19 eV, giving rise to two-dimensional migration. The vacancy migration energy across (001) Ti planes, however, was 1.32 eV, which could be lowered to 0.75 or 0.60 eV if one or two Cu antisite defects were initially present in these planes. In CuTi{sub 2}, the vacancy migration energy of 0.92 eV along the (001) Cu plane was significantly higher than in CuTi. The effective vacancy formation energies were calculated to be 1.09 eV and 0.90 eV in CuTi and CuTi{sub 2}, respectively. Interstitials created by inserting either a Cu or Ti atom had complicated configurations in which a Cu {l angle}111{r angle} split interstitial was surrounded by two or three Ti antisite defects. The interstitial formation energy was estimated to be 1.7 eV in CuTi and 1.9 eV in CuTi{sub 2}.

  14. Optimization of the Orbiting Wide-Angle Light Collectors (OWL) Mission for Charged-Particle and Neutrino Astronomy

    NASA Technical Reports Server (NTRS)

    Krizmanic, John F.; Mitchell, John W.; Streitmatter, Robert E.

    2013-01-01

    OWL [1] uses the Earth's atmosphere as a vast calorimeter to fully enable the emerging field of charged-particle astronomy with high-statistics measurements of ultra-high-energy cosmic rays (UHECR) and a search for sources of UHE neutrinos and photons. Confirmation of the Greisen-Zatsepin-Kuzmin (GZK) suppression above approx. 4 x 10(exp 19) eV suggests that most UHECR originate in astrophysical objects. Higher energy particles must come from sources within about 100 Mpc and are deflected by approx. 1 degree by predicted intergalactic/galactic magnetic fields. The Pierre Auger Array, Telescope Array and the future JEM-EUSO ISS mission will open charged-particle astronomy, but much greater exposure will be required to fully identify and measure the spectra of individual sources. OWL uses two large telescopes with 3 m optical apertures and 45 degree FOV in near-equatorial orbits. Simulations of a five-year OWL mission indicate approx. 10(exp 6) sq km/ sr/ yr of exposure with full aperture at approx. 6 x 10(exp 19) eV. Observations at different altitudes and spacecraft separations optimize sensitivity to UHECRs and neutrinos. OWL's stereo event reconstruction is nearly independent of track inclination and very tolerant of atmospheric conditions. An optional monocular mode gives increased reliability and can increase the instantaneous aperture. OWL can fully reconstruct horizontal and upward-moving showers and so has high sensitivity to UHE neutrinos. New capabilities in inflatable structures optics and silicon photomultipliers can greatly increase photon sensitivity, reducing the energy threshold for n detection or increasing viewed area using a higher orbit. Design trades between the original and optimized OWL missions and the enhanced science capabilities are described.

  15. Ultrahigh energy cosmic ray nuclei from extragalactic pulsars and the effect of their Galactic counterparts

    SciTech Connect

    Fang, Ke; Olinto, Angela V.; Kotera, Kumiko E-mail: kotera@iap.fr

    2013-03-01

    The acceleration of ultrahigh energy nuclei in fast spinning newborn pulsars can explain the observed spectrum of ultrahigh energy cosmic rays and the trend towards heavier nuclei for energies above 10{sup 19} eV as reported by the Auger Observatory. Pulsar acceleration implies a hard injection spectrum ( ∼ E{sup −1}) due to pulsar spin down and a maximum energy E{sub max} ∼ Z 10{sup 19} eV due to the limit on the spin rate of neutron stars. We have previously shown that the escape through the young supernova remnant softens the spectrum, decreases slightly the maximum energy, and generates secondary nuclei. Here we show that the distribution of pulsar birth periods and the effect of propagation in the interstellar and intergalactic media modifies the combined spectrum of all pulsars. By assuming a normal distribution of pulsar birth periods centered at 300 ms, we show that the contribution of extragalactic pulsar births to the ultrahigh energy cosmic ray spectrum naturally gives rise to a contribution to very high energy cosmic rays (VHECRs, between 10{sup 16} and 10{sup 18} eV) by Galactic pulsar births. The required injected composition to fit the observed spectrum depends on the absolute energy scale, which is uncertain, differing between Auger Observatory and Telescope Array. The contribution of Galactic pulsar births can also bridge the gap between predictions for cosmic ray acceleration in supernova remnants and the observed spectrum just below the ankle, depending on the composition of the cosmic rays that escape the supernova remnant and the diffusion behavior of VHECRs in the Galaxy.

  16. CONSTRAINING THE EMISSIVITY OF ULTRAHIGH ENERGY COSMIC RAYS IN THE DISTANT UNIVERSE WITH THE DIFFUSE GAMMA-RAY EMISSION

    SciTech Connect

    Wang Xiangyu; Liu Ruoyu; Aharonian, Felix

    2011-08-01

    Ultrahigh cosmic rays (UHECRs) with energies {approx}> 10{sup 19} eV emitted at cosmological distances will be attenuated by cosmic microwave and infrared background radiation through photohadronic processes. Lower energy extragalactic cosmic rays ({approx}10{sup 18}-10{sup 19} eV) can only travel a linear distance smaller than {approx}Gpc in a Hubble time due to the diffusion if the extragalactic magnetic fields are as strong as nano-Gauss. These prevent us from directly observing most of the UHECRs in the universe, and thus the observed UHECR intensity reflects only the emissivity in the nearby universe within hundreds of Mpc. However, UHECRs in the distant universe, through interactions with the cosmic background photons, produce UHE electrons and gamma rays that in turn initiate electromagnetic cascades on cosmic background photons. This secondary cascade radiation forms part of the extragalactic diffuse GeV-TeV gamma-ray radiation and, unlike the original UHECRs, is observable. Motivated by new measurements of extragalactic diffuse gamma-ray background radiation by Fermi/Large Area Telescope, we obtained upper limit placed on the UHECR emissivity in the distant universe by requiring that the cascade radiation they produce not exceed the observed levels. By comparison with the gamma-ray emissivity of candidate UHECR sources (such as gamma-ray bursts (GRBs) and active galactic nuclei) at high redshifts, we find that the obtained upper limit for a flat proton spectrum is {approx_equal} 10{sup 1.5} times larger than the gamma-ray emissivity in GRBs and {approx_equal} 10 times smaller than the gamma-ray emissivity in BL Lac objects. In the case of iron nuclei composition, the derived upper limit of UHECR emissivity is a factor of 3-5 times higher. Robust upper limit on the cosmogenic neutrino flux is further obtained, which is marginally reachable by the Icecube detector and the next-generation detector JEM-EUSO.

  17. Préface

    NASA Astrophysics Data System (ADS)

    Chardonnet, Christian; Millot, Guy

    2006-10-01

    COLOQ, réunion nationale biennale initiée en 1988 par la communauté française des lasers, de l'optique non linéaire et de l'optique quantique atteint sa neuvième édition. Depuis sa création, les objectifs poursuivis sont les suivants : - réunir la communauté française des lasers, de l'optique non linéaire et de l'optique quantique, en dépassant les clivages fondamental/appliqué, recherche publique/industrielle, - faire le point sur les avancées récentes, - permettre aux jeunes chercheurs de se rencontrer, de s'exprimer et de s'aguerrir au plan national. Le but est que tout thésard du domaine de l'optique puisse participer à COLOQ une fois durant sa thèse, présenter son travail et de se confronter à la communauté de l'optique. COLOQ9 s'est tenu, pour sa 9e édition, sur le campus universitaire de Dijon, du 7 au 9 septembre 2005. Il a été une grande réussite : nombre de participants (255) et de présentations scientifiques record (148 affiches), forte représentation des industriels (15) et participation d'environ 200 lycéens aux conférences grand public. Le nombre plus élevé que prévu d'affiches a rendu un peu serrée leur présentation : une attention particulière sera portée à cet aspect lors des prochaines éditions. Ces journées ont été consacrées à des conférences invitées données par des scientifiques de haut niveau et à des présentations sous forme d'affiches. Une plage de temps importante a été réservée pour des discussions autour des affiches. À proximité immédiate de la salle de conférence, l'exposition de matériels spécialisés pour les lasers, l'optique et l'optoélectronique a été une occasion pour les jeunes participants de découvrir et contacter les industriels et les autres grands acteurs de l'optique. L'année 2005 ayant été l'année mondiale de la physique, COLOQ9 a retenu comme thème central ”1905-2005 : à propos d'Einstein". Plusieurs grandes conférences ont été dédiées à ce th

  18. Simulation studies of the Cl{sup -}+ CH{sub 3}I S{sub N}2 nucleophilic substitution reaction: Comparison with ion imaging experiments

    SciTech Connect

    Zhang Jiaxu; Lourderaj, Upakarasamy; Sun Rui; Hase, William L.; Mikosch, Jochen; Wester, Roland

    2013-03-21

    In the previous work of Mikosch et al.[Science 319, 183 (2008)], ion imaging experiments were used to study the Cl{sup -}+ CH{sub 3}I {yields} ClCH{sub 3}+ I{sup -} reaction at collision energies E{sub rel} of 0.39, 0.76, 1.07, and 1.9 eV. For the work reported here MP2(fc)/ECP/d direct dynamics simulations were performed to obtain an atomistic understanding of the experiments. There is good agreement with the experimental product energy and scattering angle distributions for the highest three E{sub rel}, and at these energies 80% or more of the reaction is direct, primarily occurring by a rebound mechanism with backward scattering. At 0.76 eV there is a small indirect component, with isotropic scattering, involving formation of the pre- and post-reaction complexes. All of the reaction is direct at 1.07 eV. Increasing E{sub rel} to 1.9 eV opens up a new indirect pathway, the roundabout mechanism. The product energy is primarily partitioned into relative translation for the direct reactions, but to CH{sub 3}Cl internal energy for the indirect reactions. The roundabout mechanism transfers substantial energy to CH{sub 3}Cl rotation. At E{sub rel}= 0.39 eV both the experimental product energy partitioning and scattering are statistical, suggesting the reaction is primarily indirect with formation of the pre- and post-reaction complexes. However, neither MP2 nor BhandH/ECP/d simulations agree with experiment and, instead, give reaction dominated by direct processes as found for the higher collision energies. Decreasing the simulation E{sub rel} to 0.20 eV results in product energy partitioning and scattering which agree with the 0.39 eV experiment. The sharp transition from a dominant direct to indirect reaction as E{sub rel} is lowered from 0.39 to 0.20 eV is striking. The lack of agreement between the simulations and experiment for E{sub rel}= 0.39 eV may result from a distribution of collision energies in the experiment and/or a shortcoming in both the MP2 and BhandH simulations. Increasing the reactant rotational temperature from 75 to 300 K for the 1.9 eV collisions, results in more rotational energy in the CH{sub 3}Cl product and a larger fraction of roundabout trajectories. Even though a ClCH{sub 3}-I{sup -} post-reaction complex is not formed and the mechanistic dynamics are not statistical, the roundabout mechanism gives product energy partitioning in approximate agreement with phase space theory.

  19. The Orbiting Wide-Angle Light Collectors (OWL) Mission for Charged-Particle Astronomy

    NASA Technical Reports Server (NTRS)

    Mitchell, John; Krizmanic, J. F.; Stecker, F. W.; Streitmatter, R. E.

    2009-01-01

    The space-based OWL mission is designed to perform high-statistics measurements of ultra-high-energy cosmic rays (UHECR) using the Earth's atmosphere as a vast particle calorimeter, furthering the field of charged-particle astronomy. OWL has been developed in formal NASA instrument and mission studies and is comprised of two large telescopes separated by approx.600 km in 1000 km, near-equatorial orbits to stereoscopically image the near-UV air fluorescence emitted by UHECR-induced particle cascades. The High Resolution Fly's Eye (HiRes) Collaboration, and subsequently the Pierre Auger Observatory, recently reported confirmation of the expected Greisen-Zatsepin-Kuzmin (GZK) suppression of the UHECR flux above a few times 10(exp 19) eV. This observation is consistent with the majority of UHECR originating in astrophysical objects and reduces the need to invoke exotic physical processes. Particles observed above the GZK threshold energy must have come from sources within about 100 Mpc from the Earth. The small particle deflection angles expected at UHECR energies, with standard assumptions of extragalactic magnetic fields, are on the order of 1 degree. Thus by observing particles above the GZK threshold with sufficient exposure, there is the potential of identifying and characterizing individual UHECR sources. Auger has reported significant anisotropy in the arrival directions of UHECR at energies above about 6 10(exp 19) eV observed in the South, and a correlation to AGN in the 12th VCV catalog, suggesting that the sources of UHECR are traced by the distribution of luminous matter in the Universe. However, with similar statistics and the same event selection criteria, HiRes observations in the North are consistent with isotropy. Extended observations by Auger-South, by Telescope Array in the North, and possibly by the proposed Auger-North, will further these investigations. However, much greater exposures will be required to fully identify individual sources and

  20. Late Archean mineralised cyanobacterial mats and their modern analogs

    NASA Astrophysics Data System (ADS)

    Kazmierczak, J.; Altermann, W.; Kremer, B.; Kempe, S.; Eriksson, P. G.

    2008-09-01

    cells have the ability to bind various ions and may serve as nucleation centres for a variety of minerals [5, 6]. These, often amorphous precursor mineral phases can be transformed, during later diagenesis, into authigenic carbonates, feldspar and phyllosilicates, as observed in the case of both Nauga Formation and Lake Van cyanobacterial sheaths and capsules. The early massive appearance of benthic coccoid cyanobacteria, as evidenced by the mineralised mats in the Neoarchean Nauga Formation, and their ability to produce fine-grained limestones, confirms the significant role of these micro organisms in the formation of vast deposits of marine micritic limestones, as suggested also for younger geologic ages [7, 8]. References [1] Altermann, W. and Nelson, D. R. (1998) Sed. Geol. 120, 225-256. [2] Kazmierczak, J. and Altermann, W. (2002) Science 298, 2351. [3] Kempe, S. et al. (1991) Nature 394, 605-608. [4] Kazmierczak, J. and Altermann, W. (2002) 16th Intern. Sed. Congr. Abstract Vol., 191. [5] Douglas, S. and Beveridge, T. J. (1998) FEMS Microbiol. Ecol. 26, 79-88. [6] Barker, W. W. and Banfield, J. F. (1998) Geomicrobiol. J. 15, 223-244. [7] Kazmierczak, J. et al. (1996) Acta Palaeont. Polonica 41, 319-338. [8] Altermann, W. et al. (2006) Geobiology 4, 147- 166.

  1. Prelude and first decade, 1951-1961

    NASA Astrophysics Data System (ADS)

    Shepherd, L. R.

    The initiative leading to the establishment of the International Astronautical Federation (IAF) was taken in 1949 by the Stuttgart based Gesellschaft für Weltraumforschung (GfW), who proposed to other astronautical societies that a conference should be arranged to establish mutual co-operation. The British Interplanetary Society (BIS) agreed to organize such a conference in London in 1951, but in the interim the Groupement Astronautique Français (GAF) arranged a preliminary meeting to set up the agenda for the London meeting and to define its objectives. Representatives from astronautical groups in seven European countries and one South American society met in Paris in October 1950. Their meetings were preceded, on 30 September, by a large public gathering organized by the GAF, in the Sorbonne and was designated the Premier Congrès International d'Astronautique, a style which was to be adopted, in its English translation, for the subsequent annual conferences of the IAF. The representatives agreed that the objective of the London conference should be to create a federation of autonomous national astronautical societies, whose main purpose would be to provide an annual forum where these societies would meet. The London conference in September 1951, held in the City of Westminster, following the Paris precedent, was designated the IInd International Astronautical Congress. Astronautical and rocket societies from the ten countries were represented and became signatories to the agreement founding the IAF on 4 September 1951. The London congress set the pattern for subsequent congresses, in particular introducing technical lecture sessions. At the IIIrd Congress, held in Stuttgart, the first under the aegis of the newly founded IAF, a constitution was agreed and a Finance Committee was elected. The Constitution established that the Federation should be registered in Switzerland and be governed by a council of voting members—one only from each country. Subsequent

  2. Wrinkle reduction in post-menopausal women consuming a novel oral supplement: a double-blind placebo-controlled randomized study

    PubMed Central

    Jenkins, G; Wainwright, L J; Holland, R; Barrett, K E; Casey, J

    2014-01-01

    Synopsis Objective The maintenance of youthful skin appearance is strongly desired by a large proportion of the world's population. The aim of the present study was therefore to evaluate the effect on skin wrinkling, of a combination of ingredients reported to influence key factors involved in skin ageing, namely inflammation, collagen synthesis and oxidative/UV stress. A supplemented drink was developed containing soy isoflavones, lycopene, vitamin C and vitamin E and given to post-menopausal women with a capsule containing fish oil. Method We have performed a double-blind randomized controlled human clinical study to assess whether this cocktail of dietary ingredients can significantly improve the appearance of facial wrinkles. Results We have shown that this unique combination of micronutrients can significantly reduce the depth of facial wrinkles and that this improvement is associated with increased deposition of new collagen fibres in the dermis. Conclusion This study demonstrates that consumption of a mixture of soy isoflavones, lycopene, vitamin C, vitamin E and fish oil is able to induce a clinically measureable improvement in the depth of facial wrinkles following long-term use. We have also shown, for the first time with an oral product, that the improvement is associated with increased deposition of new collagen fibres in the dermis. Résumé Objectif Le maintien de l'apparence d'une peau jeune est vivement souhaité par une grande proportion de la population mondiale. L'objectif de la présente étude était donc d'évaluer l'effet sur les rides de la peau, d'une combinaison d'ingrédients rapportés à influer sur les facteurs clés impliqués dans le vieillissement de la peau, à savoir l'inflammation, la synthèse du collagène et le stress oxydatif / UV. Une boisson supplémentée a été élaborée contenant des isoflavones de soja, le lycopène, la vitamine C et la vitamine E et donnée aux femmes ménopausées avec une capsule contenant de l

  3. Une étude rétrospective sur l'incidence de l'insuffisance rénale chronique dans le service de Médecine Interne et Néphrologie du Centre Hospitalier Universitaire d'Antananarivo

    PubMed Central

    Ramilitiana, Benja; Ranivoharisoa, Eliane Mikkelsen; Dodo, Mihary; Razafimandimby, Evanirina; Randriamarotia, Willy Franck

    2016-01-01

    L'insuffisance rénale chronique est un problème de santé publique au niveau mondial. Dans les pays développés, cette affection survient essentiellement chez les sujets âgés, mais en Afrique, elle s'installe plutôt chez les sujets jeunes actifs. C'est une affection de lourde prise en charge dans un pays à faible revenu à cause de ses coûts. Notre but est de décrire les aspects épidémiologiques des nouveaux cas d'insuffisance rénale chronique à Madagascar. Il s'agit d'une étude rétrospective descriptive de 3 ans partant du 1er janvier 2007 au 31 décembre 2009 dans le service de Médecine Interne et Néphrologie du Centre Hospitalier Universitaire d'Antananarivo portant sur 239 patients diagnostiqués comme une insuffisance rénale chronique. L'incidence était de 8,51% parmi les patients hospitalisés dans le service. L’âge moyen des patients était de 45,4 ans avec des extrêmes de 16 et 82 ans et un sex-ratio de 1,46. Le principal antécédent était l'hypertension artérielle (59,8%). L'insuffisance rénale chronique était terminale dans 75,31% des cas (n=180). Les causes de l'insuffisance rénale chronique étaient dominées par la glomérulonéphrite chronique (40,1%), la néphroangiosclérose (35,5%). L'hémodialyse était réalisée chez 3 patients (1,26%), aucun patient n’était pas programmé pour une greffe rénale. Le taux de mortalité dans le service était de 28,87%. L'insuffisance rénale chronique est une maladie de pronostic redoutable et handicapante qui affecte les sujets jeunes à Madagascar. Son traitement reste inaccessible dans la majorité des patients. L'accent doit donc être mis principalement sur la prévention notamment une bonne prise en charge précoce des infections, de l'hypertension artérielle et du diabète pour réduire ses impacts négatifs sur la santé communautaire et publique. Le projet de la transplantation rénale - donneur vivant, traitement efficace et moins coûteux par rapport à l

  4. Epidémiologie du cancer gastrique: expérience d'un centre hospitalier marocain

    PubMed Central

    Mellouki, Ihsane; laazar, Nawal; Benyachou, Bahija; Aqodad, Nouredine; Ibrahimi, Adil

    2014-01-01

    Le cancer de l'estomac est représenté essentiellement par Les adénocarcinomes gastriques, ces derniers demeurent l'une des dix premières causes mondiales de mortalité avec un pronostic qui est péjoratif. Son incidence reste variable à travers le monde, elle est caractérisée par une importante disparité géographique. Le but de notre travail est de décrire les caractéristiques épidémiologiques de l'adénocarcinome gastrique dans notre contexte à travers une étude rétrospective, observationnelle étalée sur une période de 10 ans (Janvier 2001- Janvier 2011), incluant tous les malades admis au service d'hépato-gastroentérologie du CHU Hassan II de Fès pour prise en charge d'un adénocarcinome gastrique. Durant cette période, 343 patients étaient admis pour prise en charge d'une tumeur gastrique, dont 170 patients avaient un adénocarcinome gastrique (49.5%). L’âge moyen de ces patients était de 58±13.4 ans [16 ans-0 ans]. Dans 43.7% des cas, les patients provenaient de la région de Fès, souvent du milieu rurale. On note une nette prédominance masculine, avec une différence significative entre les 2 sexes (p < ;0.05). Les patients âgés de moins de 60ans représentaient la tranche d’âge prédominante (63%) par rapports aux patients âgés de plus de 60ans (p = 0.02). 61% des patients consultaient dans un délai allant de 1 mois à 6 mois, 30.4% des patients étaient tabagiques, ce facteur avait une relation statistiquement significative avec l'adénocarcinome gastrique (p = 0.02). la non consommation de l'alcool est inversement liée et de façon significative à l'apparition de l'adénocarcinome gastrique (p = 0.03) dans notre contexte. L'infection par Hélicobacter pylori n’était mentionnée que chez peu de malades. Les formes métastatiques au moment du diagnostic dépassaient 50% avec un taux de décès au cours de l'hospitalisation de 2.6%. Sur le plan endoscopique, la localisation antropylorique, et la forme ulc

  5. Hydrochemical and isotopic properties of the Mahmutlu and Bağdatoğlu mineralized thermal springs, Krşehir, Turkey

    NASA Astrophysics Data System (ADS)

    Ünsal, N.; Afşin, M.

    1999-12-01

    The present study identifies the hydrochemical and isotopic properties of the Mahmutlu and Bağdatoğlu mineralized thermal springs in Krşehir province, a geothermal field in central Anatolia, Turkey. Based on these properties, a hydrogeological regime is proposed in order to explain the Mahmutlu-Bağdatoğlu geothermal system. The relation between the concentrations of the environmental stable isotopes deuterium and oxygen-18 in the water is similar to the relationship in global meteoric water, indicating that the water is of meteoric origin. Evaluation of the geochemical characteristics of the water reveals that these two thermal springs belong to the same hydrogeological system. The hydrogeological system comprises a fractured limestone member of the Çevirme Formation and the Kervansaray Formation as reservoir rocks, and the Delicermak Formation as an overlying aquitard. The waters of the Mahmutlu and Bağdatoğlu springs are mainly of the Na-Cl-SO4 type that originate from the Pohrenk evaporite. The thermal waters are undersaturated with respect to calcite, dolomite, halite, and gypsum. The δ18O and δ2H contents indicate a δ18O shift in the Mahmutlu and Bağdatoğlu waters. The temperature range of the two reservoirs is estimated to be 98-158 °C, on the basis of Na+K+Ca and SiO2 geothermometers. RésuméCette étude présente les caractéristiques chimiques et isotopiques des sources thermales minéralisées de Mahmutlu et de Bağdatoğlu, dans la province de Krşehir, un champ géothermal d'Anatolie centrale (Turquie). Un fonctionnement hydrogéologique est proposéà partir de ces caractéristiques, permettant d'expliquer le système géothermal de Mahmatlu-Bağdatoğlu. La relation entre les teneurs en deutérium et celles en oxygène-18 des eaux est semblable à celle des eaux météoriques mondiales, ce qui indique que l'eau est d'origine météorique. Les caractéristiques géochimiques des eaux de ces deux sources montrent qu'elles appartiennent au

  6. Developpement D'un Modele Climatique Regional: Fizr Simulation des Conditions de Janvier de la Cote Ouest Nord Americaine

    NASA Astrophysics Data System (ADS)

    Goyette, Stephane

    1995-11-01

    . Cette nouvelle gamme de modeles-interpolateurs imbriques qualifies d'"intelligents" fait partie de la famille des modeles dits "pilotes". L'hypothese directrice de notre etude est fondee sur la supposition que le climat de fine echelle est souvent gouverne par des forcages provenant de la surface plutot que par des transports atmospheriques de grande echelle spatiale. La technique que nous proposons vise donc a guider FIZR par la Dynamique echantillonnee d'un MCG et de la forcer par la Physique du MCG ainsi que par un forcage orographique de meso-echelle, en chacun des noeuds de la grille fine de calculs. Afin de valider la robustesse et la justesse de notre modele climatique regional, nous avons choisi la region de la Cote Ouest du continent nord americain. Elle est notamment caracterisee par une distribution geographique des precipitations et des temperatures fortement influencee par le relief sous-jacent. Les resultats d'une simulation d'un mois de janvier avec FIZR demontrent que nous pouvons simuler des champs de precipitations et de temperatures au niveau de l'abri beaucoup plus pres des observations climatiques comparativement a ceux simules a partir d'un MCG. Ces performances sont manifestement attribuees au forcage orographique de meso-echelle de meme qu'aux caracteristiques de surface determinees a fine echelle. Un modele similaire a FIZR peut, en principe, etre implante sur l'importe quel MCG, donc, tout organisme de recherche implique en modelisation numerique mondiale de grande echelle pourra se doter d'un el outil de regionalisation.

  7. Syndrome métabolique chez les patients hypertendus dans le service cardiologie du CHU Yalgado Ouedraogo de Ouagadougou, Burkina Faso

    PubMed Central

    Millogo, Georges Rosario Christian; Samandoulougou, André; Yaméogo, Nobila Valentin; Yaméogo, Aristide Relwendé; Kologo, Koudougou Jonas; Toguyeni, Jean Yves; Zabsonré, Patrice

    2014-01-01

    Introduction Le syndrome métabolique constitue de nos jours un véritable problème de santé publique. Le syndrome métabolique est le moteur d'une double épidémie mondiale de diabète type II et de maladies cardiovasculaires. L'objectif de notre étude est de décrire les aspects épidémiologiques, cliniques, para cliniques et évolutifs chez les hypertendus dans le service de Cardiologie du CHU Yalgado Ouédraogo. Méthodes Il s'agissait d'une étude rétrospective sur une période de deux ans dans le service de cardiologie chez les patients hypertendus ayant un syndrome métabolique. Résultats La fréquence du syndrome métabolique était de 17,5% des patients hypertendus. Le sex ratio était de 1,2. L’âge moyen des patients étaient de 56,1 ±10,7 ans. Les patients connus hypertendus étaient de 92,1% avec une durée moyenne d’évolution de l'HTA qui était de 8,7 ± 5,9 ans. Le suivi était irrégulier dans 60% cas et une rupture du traitement dans 37,1% des cas. La dyslipidémie était notée dans 84,2% des cas et le diabète dans 60,5% des cas. La PAS moyenne était de 184,3 ± 47,3 mmHg et la PAD moyenne était de 110,7 ± 27,7 mmHg. L'HTA était sévère dans 63,2% des cas. La glycémie moyenne était de 8,3 ± 4,3 mmol/L, le LDL cholestérol moyen était de 3,5 ± 1,0 mmol/L et le taux des triglycérides moyen était de 1,6 ± 1,1 mmol/L. L'HVG électrique était notée chez 76,3% des patients et échographique dans 58,8% des cas. Les atteintes viscérales étaient neurologique dans 44,5%, rénale dans 55,3% et cardiaque dans 31,2% des cas. Le nombre moyen d'antihypertenseurs était de 3,0 ± 1,0 et 76,3% ont reçu au moins une trithérapie antihypertensive. Le taux de mortalité était de 5,3%. Conclusion Le syndrome métabolique est une pathologie qui pose la problématique de la définition qui n'est pas consensuelle d'une part et d'autre part du contrôle de ses éléments constitutifs surtout l'HTA. PMID:25883718

  8. Evaluation de la tenue du partogramme dans une maternité universitaire

    PubMed Central

    Limam, Manel; Zedini, Chekib; El Ghardallou, Meriem; Mellouli, Menel; Bougmiza, Iheb; Sahli, Jihène; Khairi, Hédi; Mtiraoui, Ali; Ajmi, Thouraya Nabli

    2015-01-01

    Introduction La mortalité maternelle est un problème majeur de santé mondiale. Une grande proportion de ces décès serait évitable par des soins adéquats, une aide à l'accouchement, la disponibilité des soins d'urgence et l'utilisation des outils d'aide à la décision tels que le partogramme. L'objectif était d’évaluer l’écart entre ce qui est censé être fait et ce qui est fait réellement pour les différents paramètres situés dans le partogramme au sein d'une maternité de 3ème niveau et élaborer des recommandations pour la mise en place d'un plan d'action. Méthodes Il s'agit d'une étude descriptive rétrospective par audit clinique, effectuée sur un échantillon de 400 dossiers obstétricaux des parturientes ayant accouchées dans la maternité du CHU Farhat Hached durant l'année 2011. Le référentiel utilisé est celui réalisé par l'Agence Nationale d'Accréditation et d'Evaluation en Santé en l'an 2000, concernant la qualité de la tenue du partogramme. Résultats La majorité des critères d’évaluation portant sur la présentation du partogramme était conforme. Deux critères concernant la variété de la présentation et le rythme cardiaque fœtal étaient non conformes parmi ceux portant sur la surveillance du fœtus. Plusieurs critères en rapport avec la surveillance de la mère étaient non conformes. Aucun des critères portant sur les traitements administrés et les marqueurs d’évènements n'est conforme. Les critères portant sur la naissance et la surveillance immédiate qui étaient non conformes sont: le début des efforts expulsifs, le mode d'accouchement, l’état du périnée, la délivrance et la révision utérine. Conclusion La véritable démarche de l'audit clinique se doit d'aller au-delà du recueil et de l'analyse des données, le but final étant l'amélioration des pratiques. PMID:26516400

  9. Development of epitaxial AlxSc1-xN for artificially structured metal/semiconductor superlattice metamaterials

    DOE PAGESBeta

    Sands, Timothy D.; Stach, Eric A.; Saha, Bivas; Saber, Sammy; Naik, Gururaj V.; Boltasseva, Alexandra; Kvam, Eric P.

    2015-02-01

    Epitaxial nitride rocksalt metal/semiconductor superlattices are emerging as a novel class of artificially structured materials that have generated significant interest in recent years for their potential application in plasmonic and thermoelectric devices. Though most nitride metals are rocksalt, nitride semiconductors in general have hexagonal crystal structure. We report rocksalt aluminum scandium nitride (Al,Sc)N alloys as the semiconducting component in epitaxial rocksalt metal/semiconductor superlattices. The AlxSc1-xN alloys when deposited directly on MgO substrates are stabilized in a homogeneous rocksalt (single) phase when x < 0.51. Employing 20 nm TiN as a seed layer on MgO substrates, the homogeneity range for stabilizingmore » the rocksalt phase has been extended to x < 0.82 for a 120 nm film. The rocksalt AlxSc1-xN alloys show moderate direct bandgap bowing with a bowing parameter, B = 1.41 ± 0.19 eV. The direct bandgap of metastable rocksalt AlN is extrapolated to be 4.70 ± 0.20 eV. The tunable lattice parameter, bandgap, dielectric permittivity, and electronic properties of rocksalt AlxSc1-xN alloys enable high quality epitaxial rocksalt metal/AlxSc1-xN superlattices with a wide range of accessible metamaterials properties.« less

  10. Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

    SciTech Connect

    Abreu, P.; Aglietta, M.; Ahn, E.J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; /Wisconsin U., Milwaukee /Lisbon, IST

    2010-06-01

    Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuzmin energy threshold, 6 x 10{sup 19} eV. The anisotropy was measured by the fraction of arrival directions that are less than 3.1{sup o} from the position of an active galactic nucleus within 75 Mpc (using the Veron-Cetty and Veron 12th catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is (38{sub -6}{sup +7})%, compared with 21% expected for isotropic cosmic rays. This is down from the early estimate of (69{sub -13}{sup +11})%. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.

  11. Health risk assessment of organochlorine pesticide exposure through dietary intake of vegetables grown in the periurban sites of Delhi, India.

    PubMed

    Chourasiya, Sapna; Khillare, P S; Jyethi, Darpa Saurav

    2015-04-01

    The study investigated the levels of organochlorine pesticides (OCPs) in different types of vegetables grown in periurban area of National Capital Region (NCR), India. Vegetable sampling was carried out in winter and summer season of 2012. A total of 20 different OCPs were determined using gas chromatography (GC) assembled with electron capture detector (ECD). Obtained results showed that average levels of ∑(20)OCP ranged from 83.8 ± 25.5 ng g(-1) in smooth gourd to 222.4 ± 90.0 ng g(-1) in cauliflower. The mean concentrations of different OCPs were observed in order of ∑HCH > ∑CHLs > drins > ∑endosulfan > ∑DDT in all vegetables except in brinjal and smooth gourd. Most of the OCP residues recorded in vegetable samples exceeded the maximum residue levels (MRLs) set by international and national regulatory agencies. Health risk assessment suggests that daily dietary OCP exposure via vegetable consumption was higher for children (mean value 4.25E-05) than adults (mean value 2.19E-05). The hazard quotient (HQ) and lifetime cancer risk (LCR) estimated from dietary exposure of these vegetables were above the acceptable limit and can be considered as a serious concern for Delhi population. PMID:25384696

  12. Low-energy electron-induced dissociation in condensed-phase L-cysteine II: a comparative study on anion desorption from chemisorbed and physisorbed films

    NASA Astrophysics Data System (ADS)

    Alizadeh, Elahe; Massey, Sylvain; Sanche, Léon; Rowntree, Paul A.

    2016-04-01

    Due to its multifunctional structure, cysteine is becoming an ideal model molecule for investigating the complex interactions of proteins with metallic surfaces such as gold nanoparticles. We report herein the results of low-energy electron induced degradation of L-cysteine films, chemisorbed on a gold substrate via the thiol group or physisorbed into a clean gold surface. The data were recorded under ultra-high vacuum conditions at room temperature. Anion yields desorbed from these films by the impact of 0.5 to 19 eV electrons provide clear evidence of the efficient decomposition of this amino acid via dissociative electron attachment (i.e., from dissociation of intermediate transient anions located between 5 and 14 eV). The peaks in the desorbed-anion yield functions, associated with DEA, are superimposed on a continuously rising signal attributed to dipolar dissociation. Similar to the results previously observed from physisorbed films, light anionic species, with masses lower than 35 amu, have been detected. In addition, we measured for first time fragments at 14 amu (CH2-) and 15 amu (CH3-) desorbing from physisorbed films, as well as heavier fragments of mass 45 and 46 amu desorbing from chemisorbed films. Contribution to the Topical Issue "Low-Energy Interactions related to Atmospheric and Extreme Conditions", edited by S. Ptasinska, M. Smialek-Telega, A. Milosavljevic, B. Sivaraman.

  13. A physiological study of the prenatal development of cutaneous sensory inputs to dorsal horn cells in the rat.

    PubMed Central

    Fitzgerald, M

    1991-01-01

    1. The response of fetal dorsal horn cells to natural and electrical stimulation of the skin of the hindpaw was recorded in vivo from the lumbar spinal cord of anaesthetized rat fetuses still in contact with their mother via the maternal circulation. 2. Responses to electrical stimulation were obtained from embryonic day 17 (E17) but spikes were not evoked by natural skin stimulation until embryonic day 19 (E19). 3. At E19 responses were evoked by pressure or pinching the skin, but responses to low intensity brush and touch were not clear until E20. 4. Receptive fields were small and response amplitudes and frequencies initially very low. However, by E20 bursts of up to fifty spikes were recorded to a single pinch and some cells displayed responses that outlasted the stimulus by 10-15 s. 5. The development of dorsal horn cutaneous evoked spike activity and consequently the ability to transmit cutaneous sensory information to the brain therefore occurs some 2 days after the development of peripheral afferent receptive fields. It is concluded that this represents the maturation time for central synaptic connections. PMID:1886065

  14. High-energy cosmic rays and neutrinos from semirelativistic hypernovae

    SciTech Connect

    Wang Xiangyu; Razzaque, Soebur; Meszaros, Peter; Dai Zigao

    2007-10-15

    The origin of the ultrahigh-energy (UHE) cosmic rays (CRs) from the second knee ({approx}6x10{sup 17} eV) above in the CR spectrum is still unknown. Recently, there has been growing evidence that a peculiar type of supernovae, called hypernovae, are associated with subenergetic gamma-ray bursts, such as SN1998bw/GRB980425 and SN2003lw/GRB031203. Such hypernovae appear to have high (up to mildly relativistic) velocity ejecta, which may be linked to the subenergetic gamma-ray bursts. Assuming a continuous distribution of the kinetic energy of the hypernova ejecta as a function of its velocity E{sub k}{proportional_to}({gamma}{beta}){sup -{alpha}} with {alpha}{approx}2, we find that (1) the external shock wave produced by the high-velocity ejecta of a hypernova can accelerate protons up to energies as high as 10{sup 19} eV; (2) the cosmological hypernova rate is sufficient to account for the energy flux above the second knee; and (3) the steeper spectrum of CRs at these energies can arise in these sources. In addition, hypernovae would also give rise to a faint diffuse UHE neutrino flux, due to p{gamma} interactions of the UHE CRs with hypernova optical-UV photons.

  15. CENTAURUS A: THE EXTRAGALACTIC SOURCE OF COSMIC RAYS WITH ENERGIES ABOVE THE KNEE

    SciTech Connect

    Biermann, Peter L.; De Souza, Vitor E-mail: vitor@ifsc.usp.br

    2012-02-10

    The origin of cosmic rays at all energies is still uncertain. In this paper, we present and explore an astrophysical scenario to produce cosmic rays with energy ranging from below 10{sup 15} to 3 Multiplication-Sign 10{sup 20} eV. We show here that just our Galaxy and the radio galaxy Cen A, each with their own galactic cosmic-ray particles but with those from the radio galaxy pushed up in energy by a relativistic shock in the jet emanating from the active black hole, are sufficient to describe the most recent data in the PeV to near ZeV energy range. Data are available over this entire energy range from the KASCADE, KASCADE-Grande, and Pierre Auger Observatory experiments. The energy spectrum calculated here correctly reproduces the measured spectrum beyond the knee and, contrary to widely held expectations, no other extragalactic source population is required to explain the data even at energies far below the general cutoff expected at 6 Multiplication-Sign 10{sup 19} eV, the Greisen-Zatsepin-Kuz'min turnoff due to interaction with the cosmological microwave background. We present several predictions for the source population, the cosmic-ray composition, and the propagation to Earth which can be tested in the near future.

  16. Patterns in ultra-high energy cosmic ray arrival directions: a possible footprint of large scale cosmic structures

    SciTech Connect

    Serpico, Pasquale Dario; /Fermilab

    2007-07-01

    The public available data of cosmic ray arrival directions with energies above 4 x 10{sup 19} eV present a broad maximum in the cumulative two-point autocorrelation function around 25 degrees. This has been interpreted as the first imprint of the filamentary pattern of large scale structures (LSS) of matter in the near universe. We analyze this suggestion in light of the clustering properties expected from a catalogue of galaxies of the local universe (redshift z {approx}< 0:06). The data reproduce particularly well the clustering properties of the nearby universe within z {approx}< 0:02. There is no statistically significant cross-correlation between data and structures, although intriguingly the nominal cross-correlation chance probability for displacements within {approx}50 degree drops from O(50%) to O(10%) using the catalogue with a smaller horizon. Our results suggest a relevant role of magnetic fields (possibly extragalactic ones, too) and/or possibly some heavy nuclei fraction in the ultra-high energy cosmic rays.

  17. Upper limit on the diffuse flux of UHE tau neutrinos from the Pierre Auger Observatory

    SciTech Connect

    Collaboration, The Pierre Auger

    2007-12-01

    The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau-neutrinos {nu}{sub {tau}} that interact in the Earth's crust. Tau leptons from {tau}{sub {tau}} charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 is used to place an upper limit on the diffuse flux of {nu}{sub {tau}} at EeV energies. Assuming an E{sub {nu}}{sup -2} differential energy spectrum the limit set at 90 % C.L. is E{sub {nu}}{sup 2} dN{sub {nu}{sub {tau}}}/dE{sub {nu}} < 1.3 x 10{sup -7} GeV cm{sup -2} s{sup -1} sr{sup -1} in the energy range 2 x 10{sup 17} eV < E{sub {nu}} < 2 x 10{sup 19} eV.

  18. CHICOS: Status and Prospects

    NASA Astrophysics Data System (ADS)

    Jillings, C. J.; Brobeck, E. G.; Larson, M. B.; Lynn, T. W.; McKeown, R. D.; Seki, R.; Falkowski, B. J.; Shoup, G. B.; Yodh, G. B.; Ganezer, K.; Hill, J.; Kieg, W. E.; Sepikas, J.; Johnson, S.

    2004-05-01

    The California HIgh school Cosmic ray ObServatory (CHICOS) is a large area (≈ 400; km^2) ground array for the study of ultra high energy cosmic rays in the Los Angeles area. The main scientific goals of CHICOS are to study the flux, energy spectrum, and angular distribution of cosmic rays (in the northern celestial hemisphere) at energies E>10^19;eV. We also demonstrate a new strategy for fielding huge arrays using urban infrastructure. Each CHICOS site employs two scintillation detectors (area ≈ 1m^2 each), generally sited at schools. At present there are 51 sites operating; 90 will be operational this year, resulting in an aperture of about 500; km^2ot sr at 10^20; eV. Preliminary observations of extended air showers and performance of the existing array will be presented and the projected performance of the 90-site array will be discussed. We wish to thank the N.S.F. for support under grants phy-0102502 and phy-0244899.

  19. Genetic markers of pigmentation are novel risk loci for uveal melanoma.

    PubMed

    Ferguson, Robert; Vogelsang, Matjaz; Ucisik-Akkaya, Esma; Rai, Karan; Pilarski, Robert; Martinez, Carlos N; Rendleman, Justin; Kazlow, Esther; Nagdimov, Khagay; Osman, Iman; Klein, Robert J; Davidorf, Frederick H; Cebulla, Colleen M; Abdel-Rahman, Mohamed H; Kirchhoff, Tomas

    2016-01-01

    While the role of genetic risk factors in the etiology of uveal melanoma (UM) has been strongly suggested, the genetic susceptibility to UM is currently vastly unexplored. Due to shared epidemiological risk factors between cutaneous melanoma (CM) and UM, in this study we have selected 28 SNPs identified as risk variants in previous genome-wide association studies on CM or CM-related host phenotypes (such as pigmentation and eye color) and tested them for association with UM risk. By logistic regression analysis of 272 UM cases and 1782 controls using an additive model, we identified five variants significantly associated with UM risk, all passing adjustment for multiple testing. The three most significantly associated variants rs12913832 (OR = 0.529, 95% CI 0.415-0.673; p = 8.47E-08), rs1129038 (OR = 0.533, 95% CI 0.419-0.678; p = 1.19E-07) and rs916977 (OR = 0.465, 95% CI 0.339-0.637; p = 3.04E-07) are correlated (r(2) > 0.5) and map at 15q12 in the region of HERC2/OCA2, which determines eye-color in the human population. Our data provides first evidence that the genetic factors associated with pigmentation traits are risk loci of UM susceptibility. PMID:27499155

  20. Surface-Wave Focal Mechanism of the 23 July 2002 Yellow-Sea Earthquake Event

    NASA Astrophysics Data System (ADS)

    Nguyen, B. V.; Hsu, V.

    2002-12-01

    The Yellow-Sea earthquake event of 23 July 2002 was reported by the USGS as follows: mb=4.7, Origin Time=12:48:08.23, Latitude = 35.563N, Longitude = 122.183E. In this study, we will present the focal mechanism of this event. Corrected Love-wave and Rayleigh-wave amplitude data from six CDSN stations and INCN station were used in the search for focal mechanism employing the technique of Nguyen and Herrmann (1992, SRL). Eigenfunctions were computed from the average crustal model that was obtained by inversion from surface-wave group velocities of these stations. Surface-wave attenuation coefficients were obtained using the technique of Tsai and Aki (1969). The result for surface-wave focal mechanism is much less as a strike-slip source than a more strike-slip one of the 4.8-mb Yellow-Sea 03 November 1992, as reported by Nguyen (1994 AGU Spring Meeting). The focal mechanism of this event has a nodal plane with dip= 65 deg., slip = 140 deg., and rake = 10 deg. The seismic moment obtained is 1.9E+23 dyne-cm. The source depth is 9 km.

  1. Laser trapped single fine particle as a probe of plasma parameters

    NASA Astrophysics Data System (ADS)

    Yamashita, Daisuke; Soejima, Masahiro; Ito, Teppei; Seo, Hyunwoong; Itagaki, Naho; Koga, Kazunori; Shiratani, Masaharu

    2015-09-01

    Here we report evaluation of electron density and temperature using optically trapped single fine particle. Experiments were carried out with a radio frequency low pressure plasma reactor, where we set two quartz windows as top and bottom flanges to irradiate an infrared laser light of 1064 nm wavelength from the bottom side. Ar plasmas were generated between a powered ring-electrode set at the bottom of the reactor and a grounded mesh placed at the center of the reactor at 100 Pa by applying 13.56 MHz voltage. The particles injected into the plasmas were monodisperse methyl methacrylate-polymer spheres of 10 μm in diameter. A negatively charged particle, which is suspended plasma sheath boundary, was trapped at the focal point of the irradiated laser light due to the transfer of momentum from the scattering of incident photons. At the beginning of the trapping, particle of 10 μm in size was trapped above 505 μm from the bottom window. After 230 min, the size and position were 9.56 μm and 520 μm, respectively. From the results, the electron density and temperature are deduced to be 1.7×109 cm-3 and 1.9 eV.

  2. Frequency of species of Eimeria in females of the Holstein-Friesian breed at the post-weaning stage during autumn and winter.

    PubMed

    Bruhn, Fábio Raphael Pascoti; Lopes, Marcos Aurélio; Demeu, Fabiana Alves; Perazza, Caio Augusto; Pedrosa, Marcos Ferrazani; Guimarães, Antônio Marcos

    2011-01-01

    The frequency of species of the genus Eimeria in a dairy herd in the municipality of Boa Esperança, Southern region of the State of Minas Gerais was assessed. From 37 females of the Friesian breed aged three to seven months, 259 feces samples were analyzed between May and September 2008. The examinations to quantify oocysts per gram of feces (OPG) and identify Eimeria species were conducted at the Veterinary Parasitology Laboratory of the Federal University of Lavras. Eleven species of Eimeria were identified, namely: E. bovis (23.2%), E. zuernii (22.6%), E. ellipsoidalis (20.3%), E. cylindrica (14.1%), E. subspherica (5.4%), E. canadensis (3.5%), E. alabamensis (2.4%), E. auburnensis (2.4%), E. pellita (2.1%), E. brasiliensis (2%) and E. bukidnonensis (1.9%). E. bovis, E. zuernii and E. ellipsoidalis were the most frequent and the ones with the highest oocyst shedding over time (p < 0.05). Differences in OPG counts were found between most months studied (p < 0.05). The large number of Eimeria species found, in particular E. bovis and E. zuernii, indicates that Eimeria sp. has significant pathogenic potential in dairy cattle in the South of Minas Gerais. PMID:22166384

  3. Genetic markers of pigmentation are novel risk loci for uveal melanoma

    PubMed Central

    Ferguson, Robert; Vogelsang, Matjaz; Ucisik-Akkaya, Esma; Rai, Karan; Pilarski, Robert; Martinez, Carlos N.; Rendleman, Justin; Kazlow, Esther; Nagdimov, Khagay; Osman, Iman; Klein, Robert J.; Davidorf , Frederick H.; Cebulla, Colleen M.; Abdel-Rahman, Mohamed H.; Kirchhoff , Tomas

    2016-01-01

    While the role of genetic risk factors in the etiology of uveal melanoma (UM) has been strongly suggested, the genetic susceptibility to UM is currently vastly unexplored. Due to shared epidemiological risk factors between cutaneous melanoma (CM) and UM, in this study we have selected 28 SNPs identified as risk variants in previous genome-wide association studies on CM or CM-related host phenotypes (such as pigmentation and eye color) and tested them for association with UM risk. By logistic regression analysis of 272 UM cases and 1782 controls using an additive model, we identified five variants significantly associated with UM risk, all passing adjustment for multiple testing. The three most significantly associated variants rs12913832 (OR = 0.529, 95% CI 0.415–0.673; p = 8.47E-08), rs1129038 (OR = 0.533, 95% CI 0.419–0.678; p = 1.19E-07) and rs916977 (OR = 0.465, 95% CI 0.339–0.637; p = 3.04E-07) are correlated (r2 > 0.5) and map at 15q12 in the region of HERC2/OCA2, which determines eye-color in the human population. Our data provides first evidence that the genetic factors associated with pigmentation traits are risk loci of UM susceptibility. PMID:27499155

  4. Neutrino and axion hot dark matter bounds after WMAP-7

    SciTech Connect

    Hannestad, Steen; Mirizzi, Alessandro; Raffelt, Georg G.; Wong, Yvonne Y.Y. E-mail: alessandro.mirizzi@desy.de E-mail: yvonne.wong@physik.rwth-aachen.de

    2010-08-01

    We update cosmological hot dark matter constraints on neutrinos and hadronic axions. Our most restrictive limits use 7-year data from the Wilkinson Microwave Anisotropy Probe for the cosmic microwave background anisotropies, the halo power spectrum (HPS) from the 7th data release of the Sloan Digital Sky Survey, and the Hubble constant from Hubble Space Telescope observations. We find 95% CL upper limits of Σm{sub ν} < 0.44 eV (no axions), m{sub a} < 0.91 eV (assuming Σm{sub ν} = 0), and Σm{sub ν} < 0.41 eV and m{sub a} < 0.72 eV for two hot dark matter components after marginalising over the respective other mass. CMB data alone yield Σm{sub ν} < 1.19 eV (no axions), while for axions the HPS is crucial for deriving m{sub a} constraints. This difference can be traced to the fact that for a given hot dark matter fraction axions are much more massive than neutrinos.

  5. Radioactive air emissions notice of construction for deactivation of the PUREX storage tunnel number 2

    SciTech Connect

    JOHNSON, R.E.

    1999-10-11

    The Plutonium-Uranium Extraction (PUREX) Plant Storage Tunnel Number 2 (hereafter referred to as the PUREX Tunnel) was built in 1964. Since that time, the PUREX Tunnel has been used for storage of radioactive and mixed waste. In 1991, the PUREX Plant ceased operations and was transitioned to deactivation. The PUREX Tunnel continued to receive PUREX Plant waste material for storage during transition activities. Before 1995, a decision was made to store radioactive and mixed waste in the PUREX Tunnel generated from other onsite sources, on a case-by-case basis. This notice of construction (NOC) describes the activities associated with the reactivation of the PUREX Tunnel ventilation system and the transfer of up to 3.5 million curies (MCi) of radioactive waste to the PUREX Tunnel from any location on the Hanford Site. The unabated total effective dose equivalent (TEDE) estimated for the hypothetical offsite maximally exposed individual (MEI) is 5.6 E-2 millirem (mrem). The abated TEDE conservatively is estimated to account for 1.9 E-5 mrem to the MEI. The following text provides information requirements of Appendix A of Washington Administrative Code (WAC) 246-247 (requirements 1 through 18).

  6. THREE DISCRETE GROUPS WITH HOMOGENEOUS CHEMISTRY ALONG THE RED GIANT BRANCH IN THE GLOBULAR CLUSTER NGC 2808

    SciTech Connect

    Carretta, E.

    2014-11-10

    We present the homogeneous reanalysis of Mg and Al abundances from high resolution UVES/FLAMES spectra for 31 red giants in the globular cluster NGC 2808. We found a well defined Mg-Al anticorrelation reaching a regime of subsolar Mg abundance ratios, with a spread of about 1.4 dex in [Al/Fe]. The main result from the improved statistics of our sample is that the distribution of stars is not continuous along the anticorrelation because they are neatly clustered into three distinct clumps, each with different chemical compositions. One group (P) shows a primordial composition of field stars of similar metallicity, and the other two (I and E) have increasing abundances of Al and decreasing abundances of Mg. The fraction of stars we found in the three components (P: 68%, I: 19%, E: 13%) is in excellent agreement with the ratios computed for the three distinct main sequences in NGC 2808: for the first time there is a clear correspondence between discrete photometric sequences of dwarfs and distinct groups of giants with homogeneous chemistry. The composition of the I group cannot be reproduced by mixing of matter with extreme processing in hot H-burning and gas with pristine, unprocessed composition, as also found in the recent analysis of three discrete groups in NGC 6752. This finding suggests that different classes of polluters were probably at work in NGC 2808 as well.

  7. Early stage of the electron kinetics in swift heavy ion tracks in dielectrics

    SciTech Connect

    Medvedev, N. A.; Rethfeld, B.; Volkov, A. E.; Shcheblanov, N. S.

    2010-09-15

    A Monte Carlo approach was applied for simulations of the early stage (first tens of femtosecond) of kinetics of the electronic subsystem of silica (SiO{sub 2}) in tracks of swift heavy ions (SHIs) decelerated in the electronic stopping regime. At the first step multiple ionizations of target atoms by a projectile (Ca{sup +19}, E=11.4 MeV/amu) were described that gave the initial spatial distributions of free electrons having different momenta as well as distributions of holes in different atomic shells. Spatial propagation of fast electrons results in secondary ionizations of target atoms as well as in energy transfer to the lattice at times much shorter than the times of atomic oscillations (phonons). The well detected front of excitation in the electronic and ionic subsystems is formed due to this propagation which cannot be described by models based on diffusion mechanisms (e.g., parabolic equations of heat diffusion). At times {approx}10 fs after the projectile passage, about {approx}0.1% of the energy is already transferred to the lattice. About 63% of the energy deposited by the ion is accumulated in holes at these times. Calculated distributions of these holes through the atomic shells are in excellent agreement with the spectroscopy experiments. Comparison with these experiments demonstrated also that relaxation of the electronic subsystem in SHI tracks in solids cannot be described adequately without taking into account intra-atomic and interatomic Auger (Knotek-Feibelman) processes.

  8. Dudley Ridge, a geomorphic trap - lacustrine gas in California

    SciTech Connect

    Sugden, H.E.

    1986-04-01

    The Dudley Ridge gas field is about 6 mi southeast of Kettleman City, California. The abandoned field straddles the boundary between T23S, R19E, and T23S, R20E, MDBM, in Kings County, California. The Tulare Lake depression was formed during the Pleistocene. It is bounded by the Temblor Range on the west, the Sierra Nevada rise on the east, the north tilt of the San Joaquin Valley to the south, and a gentle rise in the San Joaquin Valley floor to the north. The depression is almost circular except for the west side where North Kettleman dome formed a peninsula. The prevailing longshore current was to the south due to Coriolis-directed winds. Dudley Ridge was formed as a spit, trailing south off the side of North Kettleman dome. The spit is sandy, silty clay, with sand lense onlaps. The geomorphic trap formed by the sand lenses serves as a trap for the methane gas being produced in the organic-rich lake-bed sediments.

  9. Ageing and thermal recovery of paramagnetic centers induced by electron irradiation in yttria-stabilized zirconia

    NASA Astrophysics Data System (ADS)

    Costantini, J. M.; Beuneu, F.

    We have used electron spin resonance spectroscopy to study the defects induced in yttria-stabilized zirconia (YSZ) single crystals by 2.5-MeV electron irradiations. Two paramagnetic centers are produced: the first one with an axial <111> symmetry is similar to the trigonal Zr3+ electron center (T center) found after X-ray irradiation or thermo-chemical reduction, whereas the second one is a new oxygen hole center with an axial <100> symmetry different from the orthorhombic O- center induced by X-ray irradiation. At a fluence around 10(18) e/cm(2) , both centers are bleached out near 600 K, like the corresponding X-ray induced defects. At a fluence around 10(19) e/cm(2) , defects are much more stable, since complete thermal bleaching occurs near 1000 K. Accordingly, ageing of as-irradiated samples shows that high-dose defects at more stable than the low-dose ones.

  10. Structural and optical properties of Ag-doped copper oxide thin films on polyethylene napthalate substrate prepared by low temperature microwave annealing

    SciTech Connect

    Das, Sayantan; Alford, T. L.

    2013-06-28

    Silver doped cupric oxide thin films are prepared on polyethylene naphthalate (flexible polymer) substrates. Thin films Ag-doped CuO are deposited on the substrate by co-sputtering followed by microwave assisted oxidation of the metal films. The low temperature tolerance of the polymer substrates led to the search for innovative low temperature processing techniques. Cupric oxide is a p-type semiconductor with an indirect band gap and is used as selective absorption layer solar cells. X-ray diffraction identifies the CuO phases. Rutherford backscattering spectrometry measurements confirm the stoichiometry of each copper oxide formed. The surface morphology is determined by atomic force microscopy. The microstructural properties such as crystallite size and the microstrain for (-111) and (111) planes are calculated and discussed. Incorporation of Ag led to the lowering of band gap in CuO. Consequently, it is determined that Ag addition has a strong effect on the structural, morphological, surface, and optical properties of CuO grown on flexible substrates by microwave annealing. Tauc's plot is used to determine the optical band gap of CuO and Ag doped CuO films. The values of the indirect and direct band gap for CuO are found to be 2.02 eV and 3.19 eV, respectively.

  11. Germanium nanoislands grown by radio frequency magnetron sputtering: Annealing time dependent surface morphology and photoluminescence

    NASA Astrophysics Data System (ADS)

    Alireza, Samavati; Othaman, Z.; K. Ghoshal, S.; J. Amjad, R.

    2013-09-01

    Structural and optical properties of ~ 20 nm Ge nanoislands grown on Si(100) by radio frequency (rf) magnetron sputtering under varying annealing conditions are reported. Rapid thermal annealing at a temperature of 600°C for 30 s, 90 s, and 120 s are performed to examine the influence of annealing time on the surface morphology and photoluminescence properties. X-ray diffraction spectra reveal prominent Ge and GeO2 peaks highly sensitive to the annealing time. Atomic force microscope micrographs of the as-grown sample show pyramidal nanoislands with relatively high-density 1011 cm-2)). The nanoislands become dome-shaped upon annealing through a coarsening process mediated by Oswald ripening. The room temperature photoluminescence peaks for both as-grown 3.29 eV) and annealed 3.19 eV) samples consist of high intensity and broad emission, attributed to the effect of quantum confinement. The red shift (~0.10 eV) of the emission peak is attributed to the change in the size of the Ge nanoislands caused by annealing. Our easy fabrication method may contribute to the development of Ge nanostructure-based optoelectronics.

  12. Aboveground activity rhythm in Arctic black-capped marmot ( Marmota camtschatica bungei Katschenko 1901) under polar day conditions

    NASA Astrophysics Data System (ADS)

    Semenov, Youri; Ramousse, Raymond; Le Berre, Michel; Vassiliev, Vladimir; Solomonov, Nikita

    2001-04-01

    Daily aboveground activity of wild black-capped marmots of Yakutia ( Marmota camtschatica bungei) was recorded under 'polar day' conditions at 71°56' N and 127°19' E (north of the Polar Circle). From the beginning of May until the end of August, the sun was permanently above or close to the horizon. However under this condition of continuous lighting, the aboveground activity of these arctic hibernating mammals was periodic. Onset and end of activity showed marked changes throughout the seasons. Activity time increased strongly from hibernation emergence until the end of July and then decreased slowly until onset of hibernation. Below daily mean temperatures of 5 °C, activity started when the sun was 35° above the horizon, and ended when it dropped below 28°. When daily mean temperatures were above 5 °C, activity onset was synchronised with a solar altitude around 17-18° and activity ended at 10°. Activity onset was more precise relative to the solar altitude than the end of activity. This may be explained by late feeding bouts, following a midday thermal stress. In absence of rapid natural light-dark (LD) transitions that occur at civil twilight, our results suggest that the activity pattern of black-capped marmots may be synchronised by the light cycle through the solar altitude and ambient temperature.

  13. The Lateral Trigger Probability function for the ultra-high energy cosmic ray showers detected by the Pierre Auger Observatory

    SciTech Connect

    Abreu, P.; Aglietta, M.; Ahn, E.J.; Albuquerque, I.F.M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Ambrosio, M.; /INFN, Naples /Naples U. /Nijmegen U., IMAPP

    2011-01-01

    In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an Extensive Air Shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 10{sup 17} and 10{sup 19} eV and zenith angles up to 65{sup o}. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte Carlo results showing how LTP functions from data are in good agreement with simulations.

  14. Science Objectives of the JEM EUSO Mission on International Space Station

    NASA Technical Reports Server (NTRS)

    Takahashi, Yoshiyuki

    2007-01-01

    JEM-EUSO space observatory is planned with a very large exposure factor which will exceed the critical exposure factor required for observing the most of the sources within the propagational horizon of about one hundred Mpc. The main science objective of JEM-EUSO is the source-identifying astronomy in particle channel with extremey-high-energy particles. Quasi-linear tracking of the source objects through galactic magnetic field should become feasible at energy > 10(exp 20) eV for all-sky. The individual GZK profile in high statistics experiments should differ from source to source due to different distance unless Lorentz invariance is somehow limited. hi addition, JEM-EUSO has three exploratory test observations: (i), extremely high energy neutrinos beginning at E > 10(exp 19) eV: neutrinos as being expected to have a slowly increasing cross section in the Standard Model, and in particular, hundreds of times more in the extra-dimension models. (ii). fundamental physics at extreme Super LHC (Large Hadronic Collider) energies with the hierarchical unified energy much below the GUT scale, and (iii). global atmospheric observation, including large-scale and local plasma discharges, night-glow, meteorites, and others..

  15. Identification of novel and diverse rotaviruses in rodents and insectivores, and evidence of cross-species transmission into humans.

    PubMed

    Li, Kun; Lin, Xian-Dan; Huang, Kai-Yu; Zhang, Bing; Shi, Mang; Guo, Wen-Ping; Wang, Miao-Ruo; Wang, Wen; Xing, Jian-Guang; Li, Ming-Hui; Hong, Wang-Sheng; Holmes, Edward C; Zhang, Yong-Zhen

    2016-07-01

    Rotaviruses are an important cause of severe diarrheal illness in children globally. We characterized rotaviruses sampled in humans, insectivores (shrews) and rodents from urban and rural regions of Zhejiang province, China. Phylogenetic analyses revealed seven genotypic constellations of human rotaviruses with six different combinations of G and P genotypes - G3P[8] (50.06%), G9P[8] (36.16%), G1P[8] (8.92%), G2P[4] (4.63%), G3P[3] (0.12%), and G3P[9] (0.12%). In rodents and shrews sampled from the same locality we identified a novel genotype constellation (G32-P[46]-I24-R18-C17-M17-A28-N17-T19-E24-H19), a novel P genotype (P[45]), and two different AU-1-like rotaviruses associated with a G3P[3] genotype combination. Of particular note was a novel rotavirus from a human patient that was closely related to viruses sampled from rodents in the same region, indicative of a local species jump. In sum, these data are suggestive of the cross-species transmission of rodent rotaviruses into humans and for reassortment among human and animal rotaviruses. PMID:27115729

  16. Adsorption and diffusion of hydrogen on Pd(211) and Pd(111): Results from first-principles electronic structure calculations

    NASA Astrophysics Data System (ADS)

    Hong, Sampyo; Rahman, Talat S.

    2007-04-01

    We have carried out first-principles calculations of H adsorption on Pd(211) using density-functional theory with the generalized gradient approximation in the plane-wave basis to find out that the most preferred is the threefold hollow site on the terrace of Pd(211) with an adsorption energy of 0.52eV : the hcp and fcc sites being almost energetically equally favorable. For subsurface H adsorption on Pd(211), the octahedral site with an adsorption energy of 0.19eV is slightly more favorable than the tetrahedral site (0.18eV) . Our calculated activation energy barrier for H to diffuse from the preferred surface site to the subsurface one on Pd(211) is 0.33eV , as compared with 0.41eV on Pd(111). Thus, there is an enhancement of the probability of finding subsurface hydrogen in Pd(211). Additionally, we find the diffusion barriers for H on the terraces of Pd(211) to be 0.11eV , while that along the step edge to be only 0.05eV and that within the second layer (subsurface) to be 0.15eV .

  17. Excimer states in microhydrated adenine clusters.

    PubMed

    Smith, V R; Samoylova, E; Ritze, H-H; Radloff, W; Schultz, T

    2010-09-01

    We present femtosecond pump-probe mass and photoelectron spectra for adenine (A) and microhydrated A(m)(H(2)O)(n) clusters. Three distinct relaxation processes of photoexcited electronic states were distinguished: in unhydrated A, relaxation of the optically bright pipi* state occurred via the dark npi* state with respective lifetimes of <0.1 and 1.3 ps. In microhydrated clusters A(H(2)O)(n), relaxation via the npi* state is quenched by a faster relaxation process, probably involving pisigma* states. For the predominantly hydrogen-bonded adenine dimer (A(2)), excited state relaxation is dominated by monomer-like processes. When the adenine dimer is clustered with several water molecules, we observe a nanosecond lifetime from excimer states in pi-stacked clusters. From the electron spectra we estimate adiabatic ionization potentials of 8.32 eV (A), 8.27 eV (A(H(2)O)(1)), 8.19 eV (A(H(2)O)(2)), 8.10 eV (A(H(2)O)(3)), 8.18 eV (A(2)), and 8.0 eV (A(2)(H(2)O)(3-5)). PMID:20556283

  18. Thermal emission spectra from individual suspended carbon nanotubes.

    PubMed

    Liu, Zuwei; Bushmaker, Adam; Aykol, Mehmet; Cronin, Stephen B

    2011-06-28

    We study the thermal emission spectra of individual suspended carbon nanotubes induced by electrical heating. Semiconducting and metallic devices exhibit different spectra, based on their distinctive band structures. These spectra are compared with the ideal blackbody emission spectrum. In the visible wavelength range, the thermal emission spectra of semiconducting devices agree well with Planck's law, while the spectra of metallic devices show an additional peak between 1.5 and 1.9 eV. In the near-infrared wavelength range, the semiconducting nanotubes exhibit a peak around 1 eV. These additional peaks are attributed to the E11M and E22SC transitions that are thermally driven under these high applied bias voltages. These peaks show a strong polarization dependence, while the blackbody tail is unpolarized, which provides further evidence for electron-hole recombination in thermal emission. For semiconducting devices, the temperature of the nanotube is fit to Planck's law and compared with the temperatures obtained from the G band and 2D band Raman downshifts, as well as the anti-Stokes/Stokes intensity ratio. For devices showing thermal non-equilibrium, the electron temperature agrees well with G+ downshift but deviates from G_ downshift. PMID:21545117

  19. Self-assembled two-dimensional nanofluidic proton channels with high thermal stability.

    PubMed

    Shao, Jiao-Jing; Raidongia, Kalyan; Koltonow, Andrew R; Huang, Jiaxing

    2015-01-01

    Exfoliated two-dimensional (2D) sheets can readily stack to form flexible, free-standing films with lamellar microstructure. The interlayer spaces in such lamellar films form a percolated network of molecularly sized, 2D nanochannels that could be used to regulate molecular transport. Here we report self-assembled clay-based 2D nanofluidic channels with surface charge-governed proton conductivity. Proton conductivity of these 2D channels exceeds that of acid solution for concentrations up to 0.1 M, and remains stable as the reservoir concentration is varied by orders of magnitude. Proton transport occurs through a Grotthuss mechanism, with activation energy and mobility of 0.19 eV and 1.2 × 10(-3) cm(2) V(-1) s(-1), respectively. Vermiculite nanochannels exhibit extraordinary thermal stability, maintaining their proton conduction functions even after annealing at 500 °C in air. The ease of constructing massive arrays of stable 2D nanochannels without lithography should prove useful to the study of confined ionic transport, and will enable new ionic device designs. PMID:26165550

  20. Self-assembled two-dimensional nanofluidic proton channels with high thermal stability

    NASA Astrophysics Data System (ADS)

    Shao, Jiao-Jing; Raidongia, Kalyan; Koltonow, Andrew R.; Huang, Jiaxing

    2015-07-01

    Exfoliated two-dimensional (2D) sheets can readily stack to form flexible, free-standing films with lamellar microstructure. The interlayer spaces in such lamellar films form a percolated network of molecularly sized, 2D nanochannels that could be used to regulate molecular transport. Here we report self-assembled clay-based 2D nanofluidic channels with surface charge-governed proton conductivity. Proton conductivity of these 2D channels exceeds that of acid solution for concentrations up to 0.1 M, and remains stable as the reservoir concentration is varied by orders of magnitude. Proton transport occurs through a Grotthuss mechanism, with activation energy and mobility of 0.19 eV and 1.2 × 10-3 cm2 V-1 s-1, respectively. Vermiculite nanochannels exhibit extraordinary thermal stability, maintaining their proton conduction functions even after annealing at 500 °C in air. The ease of constructing massive arrays of stable 2D nanochannels without lithography should prove useful to the study of confined ionic transport, and will enable new ionic device designs.

  1. Theoretical study of atomic transport via interstitials in dilute Fe-P alloys

    NASA Astrophysics Data System (ADS)

    Meslin, E.; Fu, Chu-Chun; Barbu, A.; Gao, F.; Willaime, F.

    2007-03-01

    By combining density functional theory, empirical potential, and atomic transport model approaches, we investigate the energetics and the diffusion properties of P interstitials in dilute Fe-P alloys. Although P is a substitutional impurity in α -iron, when a self-interstitial atom (SIA) approaches a substitutional P, the P atom becomes interstitial with an energy gain of up to 1.0eV . The octahedral and the ⟨110⟩ mixed dumbbell are the lowest-energy configurations with similar stabilities. The P atoms are highly mobile in both configurations. The transitions between these two configurations also require low activation energies. The most likely mechanisms leading to long-distance diffusion of a P interstitial are proposed by ab initio calculations. The resulting effective diffusion energy estimated by the transport model is 0.19eV , which agrees with the result from resistivity recovery experiments, suggesting that the Fe-P mixed dumbbells are more mobile than the SIAs. The fast-migrating P interstitial can be deeply trapped by a substitutional P atom. The resulting complexes are very stable with a binding energy of around 1.0eV . Their mobilities are investigated by means of the dimer method using an Fe-P empirical potential. A comparison between the present predictions and existing experimental results is also discussed.

  2. The growth of nanostructured Cu2ZnSnS4 films by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Che Sulaiman, Nurul Suhada; Nee, Chen Hon; Yap, Seong Ling; Lee, Yen Sian; Tou, Teck Yong; Yap, Seong Shan

    2015-11-01

    In this work, we investigated on the growth of Cu2ZnSnS4 films by using pulsed Nd:YAG laser (355 nm) ablation of a quaternary Cu2ZnSnS4 target. Depositions were performed at laser fluence from 0.5 to 4 J cm-2. The films were grown at substrate temperature from 27 °C to 300 °C onto glass and silicon substrates. The dependence of the film morphology, composition, and optical properties are studied and discussed with respect to laser fluence and substrate temperature. Composition analysis from energy dispersive X-ray spectral results show that CZTS films with composition near stoichiometric were obtained at an optimized fluence at 2 J cm-2 by 355 nm laser where the absorption coefficient is >104 cm-1, and optical band gap from a Tauc plot was ∼1.9 eV. At high fluence, Cu and Sn rich droplets were detected which affect the overall quality of the films. The presence of the droplets was associated to the high degree of preferential and subsurface melting on the target during high fluence laser ablation. Crystallinity and optical band gap (1.5 eV) were improved when deposition was performed at substrate temperature of 100 °C.

  3. X-ray microcalorimeters with germanium resistance thermometers

    SciTech Connect

    Labov, S.; Silver, E.; Pfafman, T.; Wai, Y. ); Beeman, J.; Goulding, F.; Landis, D.; Madden, N.; Haller, E. )

    1990-08-13

    We report on the current of our work on x-ray microcalorimeters for use as high resolution x-ray spectrometers. To maximize the x-ray collecting area and the signal to noise ratio, the total heat capacity of the device must be minimized. This is best achieved if the calorimeter is divided into two components, a thermal sensor and an x-ray absorber. The thermal sensor is a neutron transmutation doped (NTD) germanium resistor made as small as possible to minimize the heat capacity of the calorimeter. The thermistor can be attached to a thin x-ray absorber with large area and low heat capacity fabricated from superconducting materials such as niobium. We discuss results from our most recent studies of such superconducting absorbers and present the x-ray spectra obtained with these composite microcalorimeters at a temperature of 0.1 K. An energy resolution of 19 eV FWHM has been measured. 14 refs., 3 figs.

  4. Preparation and characterization of hydrogenated amorphous silicon thin films and thin film solar cells produced by ion plating techniques. Final report, 1 January 1979-31 May 1980

    SciTech Connect

    1980-05-01

    Ion plating techniques for the preparation of hydrogenated amorphous silicon thin films have been successfully developed. The technique involves essentially the evaporation of elemental silicon through a d.c. produced hydrogen plasma. In this way hydrogen has been successfully incorporated into amorphous silicon films in concentrations as high as 30 atomic percent. Infrared spectroscopy indicates the usual SiH/sub x/ stretching mode at approximately 2000 cm/sup -1/. Further evidence for the bonding of hydrogen was obtained from ESR measurement of hydrogenated and unhydrogenated samples. The measured unpaired spin density was a factor of 25 less in the hydrogenated sample. The optical absorption edges of the hydrogenated films fell in the usual range between 1.7 and 1.9 eV. Electrical conductivity measurements indicated a substantial reduction in the density of defect states in the gap as expected. It was also shown that hydrogenated amorphous silicon prepared by ion-plating could be doped by co-evaporation of the dopant element during film deposition. Both co-evaporated phosphorous and co-evaporated bismuth have been found to substantially increase the dark conductivity of a-Si:H while shifting the Fermi level towards the conduction band edge. An x-ray method for estimating the density and hydrogen content of a-Si:H has been developed. The measurement of strain in a-Si:H thin films is discussed. (WHK)

  5. Suspended MoS2 devices

    NASA Astrophysics Data System (ADS)

    Jin, Taiyu; Kang, Jinyoung; Liu, Renlong; Kim, Youngchan; Lee, Changgu

    2013-03-01

    Single or a few layer MoS2 sheets have been reported to have high electric mobility and current on/off ratio comparable to those of silicon due to its semiconductor properties with bandgap of 1.3 ~ 1.9eV. However, its extremely high surface to volume ratio and low thickness prohibits it from reproducing its electronic properties on SiO2 substrates possibly because of charge scattering by surface charges and phonons. In order to investigate these surface effects, we fabricated MoS2 devices suspended from the SiO2 and characterized their electronic transport properties. We exfoliated single or a few layer MoS2 on SiO2 substrates first, and fabricated field effect transistors using e-beam lithography. After that, we suspended MoS2 sheets by etching SiO2 with hydrofluoric acid. We measured mobility and current on/off ratio before and after the etching process. We found that mobility of MoS2 devices increased by factor of 5-10 after etching for all devices. However, on/off ratio did not show significant variation. Our measurements suggest that atomically thin MoS2 devices are significantly affected by substrate surface and environment.

  6. Measuring the mass of a sterile neutrino with a very short baseline reactor experiment

    NASA Astrophysics Data System (ADS)

    Latimer, D. C.; Escamilla, J.; Ernst, D. J.

    2007-04-01

    An analysis of the world's neutrino oscillation data, including sterile neutrinos, [M. Sorel, C. M. Conrad, and M. H. Shaevitz, Phys. Rev. D 70, 073004 (2004)] found a peak in the allowed region at a mass-squared difference Δm2≅0.9eV2. We trace its origin to harmonic oscillations in the electron survival probability Pee as a function of L/E, the ratio of baseline to neutrino energy, as measured in the near detector of the Bugey experiment. We find a second occurrence for Δm2≅1.9eV2. We point out that the phenomenon of harmonic oscillations of Pee as a function of L/E, as seen in the Bugey experiment, can be used to measure the mass-squared difference associated with a sterile neutrino in the range from a fraction of an eV2 to several eV2 (compatible with that indicated by the LSND experiment), as well as measure the amount of electron-sterile neutrino mixing. We observe that the experiment is independent, to lowest order, of the size of the reactor and suggest the possibility of a small reactor with a detector sitting at a very short baseline.

  7. Autoionization states in CO{sub 2} and CS{sub 2} studied by electron impact

    SciTech Connect

    Wen, A.T.; Tremblay, D.; Tremblay, B.; Gourier, C.; Roy, D.

    1993-12-01

    A multi-angle-detector electron scattering spectrometer has been adapted to electron ejection measurements. A study of autoionization from Rydberg states has been carried out for CO{sub 2} in the continuum region 15-19 eV by low-energy electron impact. Observations have been made of structure due to excitation of these states by slow electron scattering and their decay by ejection of electrons. A multi-angle parallel detection technique has been used and this has enabled some CO{sub 2} autoionizing states resulting from non-dipole transitions to be observed clearly. The major features appearing in the ejected electron spectra of CO{sub 2} have tentatively been classified and/or assigned, and the spectral behaviour (intensity, width, and shape) of these features has been addressed as a function of incident energy and angle of ejection. In addition to the features already known, new features have been observed, and they seem to be rather sensitive to electron impact energies employed. Studies of autoionizing states in CS{sub 2} in the energy region 11-14 eV are also presented.

  8. Magic ratio of window width to grating period for van der Waals potential measurements using material gratings

    SciTech Connect

    Lonij, Vincent P. A.; Holmgren, William F.; Cronin, Alexander D.

    2009-12-15

    We report improved precision measurements of the van der Waals potential strength (C{sub 3}) for Na atoms and a silicon-nitride (SiN{sub x}) surface. We studied diffraction from nanofabricated gratings with a particular 'magic' open fraction that allows us to determine C{sub 3} without the need for separate measurements of the width of the grating openings. Therefore, finding the magic open fraction improves the precision of C{sub 3} measurements. The same effect is demonstrated for a grating with an arbitrary open fraction by rotating it to a particular 'magic' angle, yielding C{sub 3}=3.42+-0.19 eV A{sup 3} for Na and a SiN{sub x} surface. This precision is sufficient to detect a change in C{sub 3} due to a thin metal coating on the grating surface. We discuss the contribution to C{sub 3} of core electrons and edge effects.

  9. Radiation-induced defects in GaN bulk grown by halide vapor phase epitaxy

    NASA Astrophysics Data System (ADS)

    Duc, Tran Thien; Pozina, Galia; Son, Nguyen Tien; Janzén, Erik; Ohshima, Takeshi; Hemmingsson, Carl

    2014-09-01

    Defects induced by electron irradiation in thick free-standing GaN layers grown by halide vapor phase epitaxy were studied by deep level transient spectroscopy. In as-grown materials, six electron traps, labeled D2 (EC-0.24 eV), D3 (EC-0.60 eV), D4 (EC-0.69 eV), D5 (EC-0.96 eV), D7 (EC-1.19 eV), and D8, were observed. After 2 MeV electron irradiation at a fluence of 1 × 1014 cm-2, three deep electron traps, labeled D1 (EC-0.12 eV), D5I (EC-0.89 eV), and D6 (EC-1.14 eV), were detected. The trap D1 has previously been reported and considered as being related to the nitrogen vacancy. From the annealing behavior and a high introduction rate, the D5I and D6 centers are suggested to be related to primary intrinsic defects.

  10. Photoresponse properties of BaSi2 film grown on Si (100) by vacuum evaporation

    NASA Astrophysics Data System (ADS)

    Thi Trinh, Cham; Nakagawa, Yoshihiko; Hara, Kosuke O.; Takabe, Ryota; Suemasu, Takashi; Usami, Noritaka

    2016-07-01

    We have succeeded in the observation of high photoresponsivity of orthorhombic BaSi2 film grown on crystalline Si by a vacuum evaporation method, raising the prospect of its promising application in high-efficiency thin-film solar cells. Photocurrent was observed at photon energies larger than 1.28 eV, which corresponds to the band gap of evaporated BaSi2 film, indicating that the photoresponsivity originates from the BaSi2 film. The effect of the substrate temperature on the film’s properties was also investigated. The films grown at a substrate temperature larger than 500 °C are single-phase polycrystalline BaSi2 films, while those grown at a substrate temperature of 400 °C is a mixture of phases. We confirmed that undoped evaporated BaSi2 films are an n-type material with high carrier concentration. High carrier lifetime of 4.8 and 2.7 μs can be found for the films grown at 500 °C and 400 °C, respectively. BaSi2 film grown at a substrate temperature of 500 °C, which is crack-free and single-phase, shows the best photoresponsivity. The maximum value of photocurrent was obtained at photon energy of 1.9 eV, corresponding to an external quantum efficiency of 22% under reverse applied voltage of 2 V.

  11. Coulomb excitation of 44Ca and 46Ar

    NASA Astrophysics Data System (ADS)

    Calinescu, S.; Cáceres, L.; Grévy, S.; Sorlin, O.; Dombrádi, Z.; Stanoiu, M.; Astabatyan, R.; Borcea, C.; Borcea, R.; Bowry, M.; Catford, W.; Clément, E.; Franchoo, S.; Garcia, R.; Gillibert, R.; Guerin, I. H.; Kuti, I.; Lukyanov, S.; Lepailleur, A.; Maslov, V.; Morfouace, P.; Mrazek, J.; Negoita, F.; Niikura, M.; Perrot, L.; Podolyák, Z.; Petrone, C.; Penionzhkevich, Y.; Roger, T.; Rotaru, F.; Sohler, D.; Stefan, I.; Thomas, J. C.; Vajta, Z.; Wilson, E.

    2016-04-01

    The reduced transition probabilities B (E 2 ;0g.s . +→21+) of the 46Ar and 44Ca nuclei were studied using the Coulomb excitation technique at intermediate energy at the LISE/GANIL facility. The in-flight γ rays, emitted after the Coulomb excitation of their first 2+ states, were detected in an array of 64 BaF2 crystals. The present B(E 2 ↑ ) value for 44Ca, 475(36) e2fm4 , agrees well with the value of 495(35) e2fm4 obtained by averaging results of previous experiments. Consistent B (E 2 ;0g.s . +→21+) values of 225(29) e2fm4 and 234(19) e2fm4 have been obtained for 46Ar from an absolute and a relative measurement, normalized to the 44Ca value. Both results agree with the ones obtained with the same experimental technique at the NSCL facility but are a factor of 2 smaller than the shell model predictions. The drop in B (E 2 ;0g.s . +→21+) in the Ar chain at N =28 , confirmed in this experiment, shows that 46Ar is sensitive to the N =28 shell closure.

  12. Thermionic emission and work function of U and UO/sub 2/

    SciTech Connect

    McLean, W.; Chen, H.L.

    1985-02-01

    Thermionic emission measurements have been used to determine the work function (phi) of pure and oxidized uranium samples between 1100 and 1300/sup 0/K; Auger electron spectroscopy (AES) was used to verify the cleanliness and compositions of the samples. It was found that impurities present in ppM amounts in the bulk U segregated to the surface upon heating and had an appreciable effect on the zero-field emission currents as well as the slopes of the Schottkey curves obtained at various temperatures. A combination of ion-sputtering and ultra-high vacuum (UHV) annealing at high temperatures was successful in reducing the total impurity level on the hot surfaces to approx.5%. At this low concentration of impurities, well-behaved Richardson line plots were obtained with A = 135 A cm/sup -2/ K/sup -2/ and phi = 3.54 eV for pure U, and A = 128 A cm/sup -2/ K/sup -2/ and phi = 3.19 eV for UO/sub 2/. The Schottkey coefficients for clean U approached their ideal values at fields > 400 V/cm.

  13. Chemical bonds and vibrational properties of ordered (U, Np, Pu) mixed oxides

    NASA Astrophysics Data System (ADS)

    Yang, Yu; Zhang, Ping

    2013-01-01

    We use density functional theory +U to investigate the chemical bonding characters and vibrational properties of the ordered (U, Np, Pu) mixed oxides (MOXs), UNpO4,NpPuO4, and UPuO4. It is found that the 5f electronic states of different actinide elements keep their localized characters in all three MOXs. The occupied 5f electronic states of different actinide elements do not overlap with each other and tend to distribute over the energy band gap of the other actinide element's 5f states. As a result, the three ordered MOXs all show smaller band gaps than those of the component dioxides, with values of 0.91, 1.47, and 0.19 eV for UNpO4,NpPuO4, and UPuO4, respectively. Through careful charge density analysis, we further show that the U-O and Pu-O bonds in MOXs show more ionic character than in UO2 and PuO2, while the Np-O bonds show more covalent character than in NpO2. The change in covalencies in the chemical bonds leads to vibrational frequencies of oxygen atoms that are different in MOXs.

  14. Metalized T graphene: A reversible hydrogen storage material at room temperature

    SciTech Connect

    Ye, Xiao-Juan; Zhong, Wei E-mail: wzhong@nju.edu.cn; Du, You-Wei; Liu, Chun-Sheng E-mail: wzhong@nju.edu.cn; Zeng, Zhi

    2014-09-21

    Lithium (Li)-decorated graphene is a promising hydrogen storage medium due to its high capacity. However, homogeneous mono-layer coating graphene with lithium atoms is metastable and the lithium atoms would cluster on the surface, resulting in the poor reversibility. Using van der Waals-corrected density functional theory, we demonstrated that lithium atoms can be homogeneously dispersed on T graphene due to a nonuniform charge distribution in T graphene and strong hybridizations between the C-2p and Li-2p orbitals. Thus, Li atoms are not likely to form clusters, indicating a good reversible hydrogen storage. Both the polarization mechanism and the orbital hybridizations contribute to the adsorption of hydrogen molecules (storage capacity of 7.7 wt. %) with an optimal adsorption energy of 0.19 eV/H₂. The adsorption/desorption of H₂ at ambient temperature and pressure is also discussed. Our results can serve as a guide in the design of new hydrogen storage materials based on non-hexagonal graphenes.

  15. The JEM-EUSO Mission

    NASA Technical Reports Server (NTRS)

    Adams, J.H.; Christl, M.J.; Watts, J.W.

    2007-01-01

    JEM-EUSO is a science mission to explore extremes of the Universe. It observes the dark-side of the Earth and detects UV photons emitted from the extensive air shower caused by an extreme energy particle (about 10(exp 20) eV). Such a particle arrives almost straightly through our Milky Way Galaxy and is expected to allow us to trace the source location by its arrival direction. This will open the door to the new astronomy with charged particles. In its five years operation including the tilted mode, JEM-EUSO will detect at least 1,000 events with E>7 X 10(exp 19) eV and determine the energy spectrum of trans-GZK region with a statistical accuracy of several percent. JEM-EUSO is planned to be transported with HTV (H2 Transfer Vehicle) and attached to the Japanese Experiment Module/ Exposure Facility (JEM/EF) of International Space Station. JAXA has selected JEM-EUSO for one of the mission candidates of the second phase utilization of JEM/EF for the launch of early 2010s. One year-long phase-A study will be carried out under JAXA.

  16. Implications of Fermi-LAT observations on the origin of IceCube neutrinos

    SciTech Connect

    Wang, Bin; Li, Zhuo; Zhao, Xiaohong E-mail: zhaoxh@ynao.ac.cn

    2014-11-01

    The IceCube (IC) collaboration recently reported the detection of TeV-PeV extraterrestrial neutrinos whose origin is yet unknown. By the photon-neutrino connection in pp and pγ interactions, we use the Fermi-LAT observations to constrain the origin of the IC detected neutrinos. We find that Galactic origins, i.e., the diffuse Galactic neutrinos due to cosmic ray (CR) propagation in the Milky Way, and the neutrinos from the Galactic point sources, may not produce the IC neutrino flux, thus these neutrinos should be of extragalactic origin. Moreover, the extragalactic gamma-ray bursts (GRBs) may not account for the IC neutrino flux, the jets of active galactic nuclei may not produce the IC neutrino spectrum, but the starburst galaxies (SBGs) may be promising sources. As suggested by the consistency between the IC detected neutrino flux and the Waxman-Bahcall bound, GRBs in SBGs may be the sources of both the ultrahigh energy, ∼> 10{sup 19}eV, CRs and the 1–100 PeV CRs that produce the IC detected TeV-PeV neutrinos.

  17. Effects of thermal annealing on deep-level defects and minority-carrier electron diffusion length in Be-doped InGaAsN

    SciTech Connect

    Xie, S.Y.; Yoon, S.F.; Wang, S.Z.

    2005-04-01

    We report the effects of ex situ thermal annealing on the deep-level defects and the minority-carrier electron diffusion length in Be-doped, p-type In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} grown by solid source molecular-beam epitaxy. Deep-level transient spectroscopy measurements reveal two majority-carrier hole traps, HT1 (0.18 eV) and HT4 (0.59 eV), and two minority-carrier electron traps, ET1 (0.09 eV) and ET3 (0.41 eV), in the as-grown sample. For the sample with postgrowth thermal annealing, the overall deep-level defect-concentration is decreased. Two hole traps, HT2 (0.39 eV) and HT3 (0.41 eV), and one electron trap, ET2 (0.19 eV), are observed. We found that the minority-carrier electron diffusion length increases by {approx}30% and the leakage current of the InGaAsN/GaAs p-n junction decreases by 2-3 orders after thermal annealing. An increase of the net acceptor concentration after annealing is also observed and can be explained by a recently proposed three-center-complex model.

  18. Effects of rare earth substitution on the optical properties of Bi{sub 2}MoO{sub 6} for coloring applications

    SciTech Connect

    Kumari, L. Sandhya; Prabhakar Rao, P.; Sameera, S.; James, Vineetha; Koshy, Peter

    2015-10-15

    Highlights: • New class of colored compounds BiREMoO{sub 6} (RE = Pr, Nd, Sm, Tb, Yb) was synthesized. • The substitution of RE gently red shifts the absorption edge to low energy side. • The differences in band gap depend on the position of the RE f bands. • The yellow colored compounds demonstrated good coloration to plastics. - Abstract: A new class of colored inorganic compounds, BiREMoO{sub 6} (RE = Pr, Nd, Sm, Tb and Yb) has been synthesized by a solid state route. The substitution of different rare earths for Bi{sup 3+} in Bi{sub 2}MoO{sub 6} produces visible light responsive compounds by gently red shifting the absorption edge to low energy side. The visible light absorption is based on the charge transfer transitions from O{sub 2p} valence band to conduction band made of primary Mo{sub 4d} and secondary Bi{sub 6p}. The substitution of RE{sup 3+} introduces partially occupied 4f electronic levels in between the band gap and the position of 4f level depend on the number of f electrons which allows tuning the band gap. Thus the rare earth substitution provides an opportunity to tailor the band gap of Bi{sub 2}MoO{sub 6} from 2.99 eV to 2.19 eV. The developed compounds exhibited different shades of yellow hue and demonstrated good coloration to plastics.

  19. THE COSMIC-RAY ENERGY SPECTRUM OBSERVED WITH THE SURFACE DETECTOR OF THE TELESCOPE ARRAY EXPERIMENT

    SciTech Connect

    Abu-Zayyad, T.; Allen, M.; Anderson, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Hanlon, W.; Aida, R.; Azuma, R.; Fukuda, T.; Cheon, B. G.; Cho, E. J.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, H.; Fujii, T.; Fukushima, M.; and others

    2013-05-01

    The Telescope Array (TA) collaboration has measured the energy spectrum of ultra-high energy cosmic rays (UHECRs) with primary energies above 1.6 Multiplication-Sign 10{sup 18} eV. This measurement is based upon four years of observation by the surface detector component of TA. The spectrum shows a dip at an energy of 4.6 Multiplication-Sign 10{sup 18} eV and a steepening at 5.4 Multiplication-Sign 10{sup 19} eV which is consistent with the expectation from the GZK cutoff. We present the results of a technique, new to the analysis of UHECR surface detector data, that involves generating a complete simulation of UHECRs striking the TA surface detector. The procedure starts with shower simulations using the CORSIKA Monte Carlo program where we have solved the problems caused by use of the ''thinning'' approximation. This simulation method allows us to make an accurate calculation of the acceptance of the detector for the energies concerned.

  20. Heteroaromatic and aniline derivatives of piperidines as potent ligands for vesicular acetylcholine transporter

    PubMed Central

    Li, Junfeng; Zhang, Xiang; Zhang, Zhanbin; Padakanti, Prashanth K.; Jin, Hongjun; Cui, Jinquan; Li, Aixiao; Zeng, Dexing; Rath, Nigam P.; Flores, Hubert; Perlmutter, Joel S.; Parsons, Stanley M.; Tu, Zhude

    2013-01-01

    To identify suitable lipophilic compounds having high potency and selectivity for vesicular acetylcholine transporter (VAChT), a heteroaromatic ring or a phenyl group was introduced into the carbonyl-containing scaffold for VAChT ligands. Twenty new compounds with ALog D values between 0.53-3.2 were synthesized, and their in vitro binding affinities were assayed. Six of them (19a, 19e, 19g, 19k and 24a-b) displayed high affinity for VAChT (Ki = 0.93 – 18 nM for racemates) and moderate to high selectivity for VAChT over σ1 and σ2 receptors (Ki = 44 – 4400-fold). These compounds have a methyl or a fluoro substitution that provides the position for incorporating PET radioisotopes C-11 or F-18. Compound (-)-[11C]24b (Ki = 0.78 for VAChT, 900-fold over σ receptors) was successfully synthesized and evaluated in vivo in rats and nonhuman primates. The data revealed that (-)-[11C]24b has highest binding in striatum and has favorable pharmacokinetics in the brain. PMID:23802889

  1. Radar Detection of Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Myers, Isaac

    2012-03-01

    Progress in the study of high energy cosmic ray physics is limited by low flux. In order to collect substantial statistics above 10^19 eV, the two largest ground arrays currently in operation cover 800 km^2 (Telescope Array, Utah) and 3000 km^2 (Auger Observatory, Argentina). The logistics and cost of an order-of-magnitude increase in ground array aperture is prohibitive. In the literature, radar detection experiments have been proposed but substantial results have not been reported. We have deployed a low-power (1500 W) bistatic radar facility overlapping the Telescope Array (TA) in Delta, Utah. Data acquisition systems for the radar receivers were developed in parallel. This system has taught us a great deal, but our current focus is building and deploying a 40 kW transmitter and new high-gain transmitting antenna. Theoretical simulations of CR air shower scattering of radar show that coincidences with the ground array should be detected with this new system. An FCC license for the new transmitter/antenna has been obtained. Systems monitoring and data logging systems, as well as a new, intelligent self-triggered DAQ continue to be developed. We hope to deploy the self-triggered DAQ during the first few months of 2012 and complete the transmitte

  2. Excitons in Alkali Halides: Analysis of Type I STE Spectrafootnote[1] Supported in part by the State of Vermont and the National Science Foundation under EPSCoR/grant RII-8610679.

    NASA Astrophysics Data System (ADS)

    Malghani, M. S.; Smith, D. Y.

    1997-03-01

    We have analyzed the newly observedfootnote[2] K. Edamatsu and M Hirai, Mat. Sci. Forum (in press). transient IR absorption spectra of ``Type I'' self-trapped excitons in NaBr and NaI for the exciton's spatial extent and the exciton Rydberg. A Vinti sum-rule analysis shows that the electron orbits extend well into the bulk crystal with radii 2.6 to 4 times the interatomic spacing. This corresponds to an electron distribution covering 100 or more lattice sites. The transient absorption line shape can be fit extremely well with a phonon-broadened hydrogenic spectrum. Gaussian broadening yields significantly better fits than Lorentzians. Rydberg values are 0.27 eV for NaBr and 0.19 eV for NaI. The large radii, small Rydberg and approximate Wannier-exciton-like properties of the absorption strongly suggest the originalfootnote[3]M. N. Kabler, Phys. Rev. 136, A1296 (1964); R. B. Murray and F. J. Keller, Phys. Rev. 137, A942 (1965). ``on-center'' model for STEs applies to these materials.

  3. Spectroscopic study of graphene nanoribbons formed by crystallographic etching of highly oriented pyrolytic graphite

    NASA Astrophysics Data System (ADS)

    Sugiyama, Yoshihiro; Kubo, Osamu; Omura, Ryosuke; Shigehara, Masaaki; Tabata, Hiroshi; Mori, Nobuya; Katayama, Mitsuhiro

    2014-09-01

    We report a scanning tunneling spectroscopy study systematically performed on graphene nanoribbons (GNRs) with various widths and layer numbers. The GNRs are formed on highly oriented pyrolytic graphite (HOPG) by crystallographic etching, as reported by Datta and co-workers [Nano Lett. 8, 1912 (2008)]. Regardless of the width and layer numbers, GNRs having zigzag edges exhibit a peak at the Fermi energy in their local density of states (LDOS) when measured near the edges, whereas no peak appears away from the edges. On the other hand, a depression of the LDOS emerges at the Fermi energy in the case of a GNR having armchair edges with no relation to the measured position in an identical GNR. The energy gap of the LDOS depression monotonically decreases with increasing GNR width, whereas there is no apparent dependence on the layer numbers. By comparison with the band structure calculated by a nearest-neighbor tight-binding method, it is suggested that the overlap of wave functions between the topmost layer and the underlayers is negligible, resulting in an LDOS similar to that on an isolated monolayer GNR even on an HOPG substrate. From the quantitative scaling of energy gaps (Egap) of LDOS depression with respect to GNR widths (W), the relation between the two is obtained as Egap = 1.9 [eV nm]/W.

  4. 40 CFR Appendix II to Part 266 - Tier I Feed Rate Screening Limits for Total Chlorine

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 5.3E+01 4.1E+01 10 1.2E+02 6.2E+01 5.8E+01 12 1.3E+02 7.7E+01 7.2E+01 14 1.5E+02 9.1E+01 9.1E+01 16 1.7E+02 1.2E+02 1.1E+02 18 1.9E+02 1.4E+02 1.2E+02 20 2.1E+02 1.8E+02 1.3E+02 22 2.4E+02 2.3E+02 1....8E+02 2.1E+02 35 5.3E+02 9.6E+02 2.6E+02 40 6.2E+02 1.4E+03 3.3E+02 45 8.2E+02 2.0E+03 4.0E+02 50...

  5. 40 CFR Appendix III to Part 266 - Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .../hr) HCl (g/hr) 4 8.2E+01 1.4E+03 4.2E+01 7.3E+02 1.9E+01 3.3E+02 6 9.1E+01 1.6E+03 4.8E+01 8.3E+02 2.8E+01 4.9E+02 8 1.0E+02 1.8E+03 5.3E+01 9.2E+02 4.1E+01 7.1E+02 10 1.2E+02 2.0E+03 6.2E+01 1.1E+03 5.8E+01 1.0E+03 12 1.3E+02 2.3E+03 7.7E+01 1.3E+03 7.2E+01 1.3E+03 14 1.5E+02 2.6E+03 9.1E+01 1.6E+03...

  6. 40 CFR Appendix II to Part 266 - Tier I Feed Rate Screening Limits for Total Chlorine

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 5.3E+01 4.1E+01 10 1.2E+02 6.2E+01 5.8E+01 12 1.3E+02 7.7E+01 7.2E+01 14 1.5E+02 9.1E+01 9.1E+01 16 1.7E+02 1.2E+02 1.1E+02 18 1.9E+02 1.4E+02 1.2E+02 20 2.1E+02 1.8E+02 1.3E+02 22 2.4E+02 2.3E+02 1....8E+02 2.1E+02 35 5.3E+02 9.6E+02 2.6E+02 40 6.2E+02 1.4E+03 3.3E+02 45 8.2E+02 2.0E+03 4.0E+02 50...

  7. 40 CFR Appendix III to Part 266 - Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .../hr) HCl (g/hr) 4 8.2E+01 1.4E+03 4.2E+01 7.3E+02 1.9E+01 3.3E+02 6 9.1E+01 1.6E+03 4.8E+01 8.3E+02 2.8E+01 4.9E+02 8 1.0E+02 1.8E+03 5.3E+01 9.2E+02 4.1E+01 7.1E+02 10 1.2E+02 2.0E+03 6.2E+01 1.1E+03 5.8E+01 1.0E+03 12 1.3E+02 2.3E+03 7.7E+01 1.3E+03 7.2E+01 1.3E+03 14 1.5E+02 2.6E+03 9.1E+01 1.6E+03...

  8. 40 CFR Appendix II to Part 266 - Tier I Feed Rate Screening Limits for Total Chlorine

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 5.3E+01 4.1E+01 10 1.2E+02 6.2E+01 5.8E+01 12 1.3E+02 7.7E+01 7.2E+01 14 1.5E+02 9.1E+01 9.1E+01 16 1.7E+02 1.2E+02 1.1E+02 18 1.9E+02 1.4E+02 1.2E+02 20 2.1E+02 1.8E+02 1.3E+02 22 2.4E+02 2.3E+02 1....8E+02 2.1E+02 35 5.3E+02 9.6E+02 2.6E+02 40 6.2E+02 1.4E+03 3.3E+02 45 8.2E+02 2.0E+03 4.0E+02 50...

  9. 40 CFR Appendix II to Part 266 - Tier I Feed Rate Screening Limits for Total Chlorine

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 5.3E+01 4.1E+01 10 1.2E+02 6.2E+01 5.8E+01 12 1.3E+02 7.7E+01 7.2E+01 14 1.5E+02 9.1E+01 9.1E+01 16 1.7E+02 1.2E+02 1.1E+02 18 1.9E+02 1.4E+02 1.2E+02 20 2.1E+02 1.8E+02 1.3E+02 22 2.4E+02 2.3E+02 1....8E+02 2.1E+02 35 5.3E+02 9.6E+02 2.6E+02 40 6.2E+02 1.4E+03 3.3E+02 45 8.2E+02 2.0E+03 4.0E+02 50...

  10. 40 CFR Appendix II to Part 266 - Tier I Feed Rate Screening Limits for Total Chlorine

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 5.3E+01 4.1E+01 10 1.2E+02 6.2E+01 5.8E+01 12 1.3E+02 7.7E+01 7.2E+01 14 1.5E+02 9.1E+01 9.1E+01 16 1.7E+02 1.2E+02 1.1E+02 18 1.9E+02 1.4E+02 1.2E+02 20 2.1E+02 1.8E+02 1.3E+02 22 2.4E+02 2.3E+02 1....8E+02 2.1E+02 35 5.3E+02 9.6E+02 2.6E+02 40 6.2E+02 1.4E+03 3.3E+02 45 8.2E+02 2.0E+03 4.0E+02 50...

  11. 40 CFR Appendix III to Part 266 - Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .../hr) HCl (g/hr) 4 8.2E+01 1.4E+03 4.2E+01 7.3E+02 1.9E+01 3.3E+02 6 9.1E+01 1.6E+03 4.8E+01 8.3E+02 2.8E+01 4.9E+02 8 1.0E+02 1.8E+03 5.3E+01 9.2E+02 4.1E+01 7.1E+02 10 1.2E+02 2.0E+03 6.2E+01 1.1E+03 5.8E+01 1.0E+03 12 1.3E+02 2.3E+03 7.7E+01 1.3E+03 7.2E+01 1.3E+03 14 1.5E+02 2.6E+03 9.1E+01 1.6E+03...

  12. 40 CFR Appendix III to Part 266 - Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .../hr) HCl (g/hr) 4 8.2E+01 1.4E+03 4.2E+01 7.3E+02 1.9E+01 3.3E+02 6 9.1E+01 1.6E+03 4.8E+01 8.3E+02 2.8E+01 4.9E+02 8 1.0E+02 1.8E+03 5.3E+01 9.2E+02 4.1E+01 7.1E+02 10 1.2E+02 2.0E+03 6.2E+01 1.1E+03 5.8E+01 1.0E+03 12 1.3E+02 2.3E+03 7.7E+01 1.3E+03 7.2E+01 1.3E+03 14 1.5E+02 2.6E+03 9.1E+01 1.6E+03...

  13. 40 CFR Appendix III to Part 266 - Tier II Emission Rate Screening Limits for Free Chlorine and Hydrogen Chloride

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .../hr) HCl (g/hr) 4 8.2E+01 1.4E+03 4.2E+01 7.3E+02 1.9E+01 3.3E+02 6 9.1E+01 1.6E+03 4.8E+01 8.3E+02 2.8E+01 4.9E+02 8 1.0E+02 1.8E+03 5.3E+01 9.2E+02 4.1E+01 7.1E+02 10 1.2E+02 2.0E+03 6.2E+01 1.1E+03 5.8E+01 1.0E+03 12 1.3E+02 2.3E+03 7.7E+01 1.3E+03 7.2E+01 1.3E+03 14 1.5E+02 2.6E+03 9.1E+01 1.6E+03...

  14. The Galactic supersoft X-ray binary RXJ0925.7-4758 (MR Vel)

    NASA Astrophysics Data System (ADS)

    Baruah, M.; Prodhani, N.

    2016-06-01

    Close binary supersoft X-ray sources (CBSS) are believed to be an accreting white dwarf (WD) in a close binary with near-main-sequence companion, which can provide large mass accretion rates (~1×10^-7 - 6×10^-7Msol yr-1). During such high accretion rates, hydrogen shell burning consumes hydrogen at the same rate as the WD accretes. Using most recent proton capturing reaction rates and beta-decay rates the cyclic reactions have been studied. In the present work, effort has been made to explain the observed characteristics of the source RXJ0925.7-4758 considering the above mentioned model. The calculated values of Luminosity (8.56×10^37erg/sec) and Effective temperature (94.19 eV) tally well with the observed ones. The Color temperature of RXJ0925.7-4758 near the photosphere has been determined as 106 eV. Photo ionisation code CLOUDY has been used to explain the observed absorption edges in the spectrum of RXJ0925.7-4758.

  15. Electronic and optical properties of novel carbon allotropes

    DOE PAGESBeta

    Wang, Zhanyu; Dong, F.; Shen, B.; Zhang, R. J.; Zheng, Y. X.; Chen, L. Y.; Wang, S. Y.; Wang, C. Z.; Ho, K. M.; Fan, Yuan -Jia; et al

    2016-01-22

    The vibrational properties, electronic structures and optical properties of novel carbon allotropes, such as monolayer penta-graphene (PG), double-layer PG and T12-carbon, were studied by first-principles calculations. Results of phonon calculations demonstrate that these exotic carbon allotropes are dynamically stable. The bulk T12 phase is an indirect-gap semiconductor having a quasiparticle (QP) bandgap of ~5.19 eV. When the bulk material transforms to a two-dimensional (2D) phase, the monolayer and double-layer PG become quasi-direct gap semiconductors with smaller QP bandgaps of ~4.48 eV and ~3.67 eV, respectively. Furthermore, the partial charge density analysis indicates that the 2D phases retain part of themore » electronic characteristics of the T12 phase. The linear photon energy-dependent dielectric functions and related optical properties including refractive index, extinction coefficient, absorption spectrum, reflectivity, and energy-loss spectrum were also computed and discussed. Additionally, the chemical stability of monolayer PG and the electronic and optical properties of double-side hydrogenated monolayer PG were also investigated. Furthermore, the results obtained from our calculations are beneficial to practical applications of these exotic carbon allotropes in optoelectronics and electronics.« less

  16. Modification of Defect Structures in Graphene by Electron Irradiation: Ab Initio Molecular Dynamics Simulations

    SciTech Connect

    Wang, Zhiguo; Zhou, Yungang; Bang, Junhyeok; Prange, Micah P.; Zhang, Shengbai; Gao, Fei

    2012-08-02

    Defects play an important role on the unique properties of the sp2-bonded materials, such as graphene. The creation and evolution of mono-vacancy, di-vacancy, Stone-Wales (SW) and grain boundaries (GBs) under irradiation in graphene are investigated using density functional theory and time-dependent density functional theory molecular dynamics simulations. It is of great interest to note that the patterns of these defects can be controlled through electron irradiation. The SW defects can be created by electron irradiation with energy of above the displacement threshold energy (Td, {approx}19 eV) and can be healed with an energy (14-18 eV) lower than Td. The transformation between four types of divacancies, V2(5-8-5), V2(555-777), V2(5555-6-7777), and V2(55-77) can be realized through bond rotation induced by electron irradiation. The migrations of divancancies, SW defects, and GBs can also be controlled by electron irradiation. Thus, electron irradiation can serve as an important tool to modify morphology in a controllable manner, and to tailor the physical properties of graphene.

  17. Molecular Frame Photoemission: Probe of the Photoionization Dynamics for Molecules in the Gas Phase

    NASA Astrophysics Data System (ADS)

    Dowek, D.; Picard, Y. J.; Billaud, P.; Elkharrat, C.; Houver, J. C.

    2009-04-01

    Molecular frame photoemission is a very sensitive probe of the photoionization (PI) dynamics of molecules. This paper reports a comparative study of non-resonant and resonant photoionization of D2 induced by VUV circularly polarized synchrotron radiation at SOLEIL at the level of the molecular frame photoelectron angular distributions (MFPADs). We use the vector correlation method which combines imaging and time-of-flight resolved electron-ion coincidence techniques, and a generalized formalism for the expression of the I(χ, θe, varphie) MFPADs, where χ is the orientation of the molecular axis with respect to the light quantization axis and (θe, varphie) the electron emission direction in the molecular frame. Selected MFPADs for a molecule aligned parallel or perpendicular to linearly polarized light, or perpendicular to the propagation axis of circularly polarized light, are presented for dissociative photoionization (DPI) of D2 at two photon excitation energies, hν = 19 eV, where direct PI is the only channel opened, and hν = 32.5 eV, i.e. in the region involving resonant excitation of Q1 and Q2 doubly excited state series. We discuss in particular the properties of the circular dichroism characterizing photoemission in the molecular frame for direct and resonant PI. In the latter case, a remarkable behavior is observed which may be attributed to the interference occurring between undistinguishable autoionization decay channels.

  18. Genome-wide association studies of pit-and-fissure- and smooth-surface caries in permanent dentition.

    PubMed

    Zeng, Z; Shaffer, J R; Wang, X; Feingold, E; Weeks, D E; Lee, M; Cuenco, K T; Wendell, S K; Weyant, R J; Crout, R; McNeil, D W; Marazita, M L

    2013-05-01

    While genetics clearly influences dental caries risk, few caries genes have been discovered and validated. Recent studies have suggested differential genetic factors for primary dentition caries and permanent dentition caries, as well as for pit-and-fissure- (PF) and smooth- (SM) surface caries. We performed separate GWAS for caries in permanent-dentition PF surfaces (1,017 participants, adjusted for age, sex, and the presence of Streptococcus mutans) and SM surfaces (1,004 participants, adjusted for age, education group, and the presence of Streptococcus mutans) in self-reported whites (ages 14 to 56 yrs). Caries scores were derived based on visual assessment of each surface of each tooth; more than 1.2 million SNPs were either successfully genotyped or imputed and were tested for association. Two homologous genes were suggestively associated: BCOR (Xp11.4) in PF-surface caries (p value = 1.8E-7), and BCORL1 (Xq26.1) in SM-surface caries (p value = 1.0E-5). BCOR mutations cause oculofaciocardiodental syndrome, a Mendelian disease involving multiple dental anomalies. Associations of other plausible cariogenesis genes were also observed for PF-surface caries (e.g., INHBA, p value = 6.5E-6) and for SM-surface caries (e.g., CXCR1 and CXCR2, p value = 1.9E-6). This study supports the notion that genes differentially affect cariogenesis across the surfaces of the permanent dentition, and nominates several novel genes for investigation. PMID:23470693

  19. Electrical conduction and deep levels in polycrystalline diamond films

    NASA Astrophysics Data System (ADS)

    Gonon, P.; Deneuville, A.; Fontaine, F.; Gheeraert, E.

    1995-12-01

    We have studied the dark conductivity (field, temperature, and frequency dependence), and the photoconductivity in undoped polycrystalline diamond films. Detailed analysis reveals that either of two alternative models can be invoked to explain all the observed features of the dark conductivity. The first model is a Hill-type hopping conduction involving the presence of discrete acceptor states located at 0.91 eV above the valence band with a density around 1017 cm-3. The second model involves the presence of a band-tail of acceptor states extending about 1 eV above the valence band. In this case, variable range hopping conduction dominates at low fields with a density of states at the Fermi level around 5×1015 cm-3 eV-1, while space charge limited currents dominate at high fields. The states controlling the dark conductivity give rise to photoconduction with a threshold around 0.85 eV and a peak at 1.1 eV. The shape of the photoconductivity spectrum suggests that lattice relaxation (with a Franck-Condon shift around 0.08 eV) occurs at these states. Peaks in the photoconductivity at 1.4 eV and at 1.9 eV give evidence for the presence of deeper states in these films.

  20. A Comparison of Electron-Transfer Dynamics inIonic Liquids and Neutral Solvents

    SciTech Connect

    Wishart J. F.; Lee, H.Y.; Issa, J.B.; Isied, S.S.; Castner, Jr., E.W.; Pan, Y.; Hussey, C.L.; Lee, K.S.

    2012-03-01

    The effect of ionic liquids on photoinduced electron-transfer reactions in a donor-bridge-acceptor system is examined for two ionic liquid solvents, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide and tributylmethylammonium bis(trifluoromethylsulfonyl)amide. The results are compared with those for the same system in methanol and acetonitrile solution. Electron-transfer rates were measured using time-resolved fluorescence quenching for the donor-bridge-acceptor system comprising a 1-N,1-N-dimethylbenzene-1,4-diamine donor, a proline bridge, and a coumarin 343 acceptor. The photoinduced electron-transfer processes are in the inverted regime (-{Delta}G > {lambda}) in all four solvents, with driving forces of -1.6 to -1.9 eV and estimated reorganization energies of about 1.0 eV. The observed electron-transfer kinetics have broadly distributed rates that are generally slower in the ionic liquids compared to the neutral solvents, which also have narrower rate distributions. To describe the broad distributions of electron-transfer kinetics, we use two different models: a distribution of exponential lifetimes and a discrete sum of exponential lifetimes. Analysis of the donor-acceptor electronic coupling shows that for ionic liquids this intramolecular electron-transfer reaction should be treated using a solvent-controlled electron-transfer model.

  1. Oxygen loss induced by swift heavy ions of low and high dE/dx in PMMA thin films

    NASA Astrophysics Data System (ADS)

    Thomaz, R.; Gutierres, L. I.; Morais, J.; Louette, P.; Severin, D.; Trautmann, C.; Pireaux, J. J.; Papaléo, R. M.

    2015-12-01

    Investigations on the chemical modifications induced by swift heavy ions in PMMA thin films were carried out using beams of high dE/dx (2.2 GeV Bi, 14,090 eV/nm) and low dE/dx (2 MeV H, 19 eV/nm). The induced chemical modifications were monitored by XPS for films with initial thickness of 50 and 100 nm. For both beams, the irradiation decreased the amount of carbon atoms bound to oxygen (Cdbnd O and Csbnd Osbnd C), with a larger decrease of the carboxyl moiety, as expected. However, the chemical changes induced by light and heavy ions were qualitatively different. For the same mean deposited energy density, proton irradiation induced a decrease of the relative intensity of the carbon-oxygen bonds up to ∼20% larger than the irradiation with Bi ions. This suggests a greater importance of particle ejection by unzipping of PMMA chains at high dE/dx, which tends to keep the O/C ratio closer to the pristine value.

  2. Dynamic modulation of electronic properties of graphene by localized carbon doping using focused electron beam induced deposition.

    PubMed

    Kim, S; Russell, M; Henry, M; Kim, S S; Naik, R R; Voevodin, A A; Jang, S S; Tsukruk, V V; Fedorov, A G

    2015-09-28

    We report on the first demonstration of controllable carbon doping of graphene to engineer local electronic properties of a graphene conduction channel using focused electron beam induced deposition (FEBID). Electrical measurements indicate that an "n-p-n" junction on graphene conduction channel is formed by partial carbon deposition near the source and drain metal contacts by low energy (<50 eV) secondary electrons due to inelastic collisions of long range backscattered primary electrons generated from a low dose of high energy (25 keV) electron beam (1 × 10(18) e(-) per cm(2)). Detailed AFM imaging provides direct evidence of the new mechanism responsible for dynamic evolution of the locally varying graphene doping. The FEBID carbon atoms, which are physisorbed and weakly bound to graphene, diffuse towards the middle of graphene conduction channel due to their surface chemical potential gradient, resulting in negative shift of Dirac voltage. Increasing a primary electron dose to 1 × 10(19) e(-) per cm(2) results in a significant increase of carbon deposition, such that it covers the entire graphene conduction channel at high surface density, leading to n-doping of graphene channel. Collectively, these findings establish a unique capability of FEBID technique to dynamically modulate the doping state of graphene, thus enabling a new route to resist-free, "direct-write" functional patterning of graphene-based electronic devices with potential for on-demand re-configurability. PMID:26302897

  3. Residual thermal desorption studies of Ga adatoms on trenched Si(5 5 12) surface

    NASA Astrophysics Data System (ADS)

    Kumar, Praveen; Kumar, Mahesh; Shivaprasad, S. M.

    2013-10-01

    We present here the thermal stability studies of the room temperature adsorbed Ga/Si(5 5 12) interfaces in the monolayer coverage regime, using AES and LEED as in-situ UHV characterization probes. Ga grows in Stranski-Krastanov growth mode at RT on the 2 × 1 reconstructed Si(5 5 12) surface where islands form on top of 2 ML of flat pseudomorphic Ga, yielding a (1 × 1) LEED pattern for coverages of 1.2 ML and above. When this RT adsorbed Ga/Si(5 5 12) interface is annealed at different temperatures, initially the strained Ga adlayers relax by agglomerating into 3D islands on top of a single Ga monolayer with an activation energy of 0.19 eV in the temperature range of 200-300 °C. The remnant Ga monolayer with a sharp (1 × 1) LEED pattern desorbs at temperature >400 °C, yielding the (1 1 2)-6 × 1 and 2 × (3 3 7) sub-monolayer superstructural. Finally at 720 °C Ga completely desorbs from the surface and leaves the clean 2 × 1 reconstructed Si(5 5 12) surface. The studies demonstrate the richness of the atomically trenched high index Si(5 5 12) surface, in obtaining several anisotropic features that can be used as templates to grow self-assembled nanostructures.

  4. Prognostic implications of immunohistochemistry markers for EGFR-TKI therapy in Chinese patients with advanced lung adenocarcinoma harboring EGFR mutations

    PubMed Central

    Zhang, Ruiguang; Li, Yan; Nie, Xiu; Dong, Xiaorong; Wu, Gang

    2016-01-01

    Background Epidermal growth factor receptor (EGFR) mutations in non-small-cell lung cancer predict dramatic clinical responses to tyrosine kinase inhibitor (TKI) treatment. The conclusion on EGFR mutation-specific antibodies by immunohistochemistry (IHC) is not consistent. We evaluated the clinical availability of EGFR mutation-specific antibodies, investigating the prediction role of mutant EGFRs and other IHC markers in TKI therapy in patients with advanced lung adenocarcinoma. Materials and methods We analyzed 637 primary lung adenocarcinomas from an unselected Chinese population. For IHC, antibodies against EGFR exon 19 E746_A750 deletions, exon 21 L858R mutations, thyroid transcription factor-1 (TTF-1), and Napsin-A were applied. Positivity was defined as staining score >0. Results Specificities of E746_A750 and L858R antibodies were 99.6% and 99.3%, while sensitivities were 86.0% and 82.7%, respectively. Tumors with Napsin-A positivity, TTF-1 positivity, EGFR mutations, and lepidic pattern showed a lower marker of proliferation index (Ki67). Higher expression scores of mutant EGFR protein, TTF-1 positivity, lower Ki67 proliferation index, and lepidic pattern were associated with longer progression-free survival. Conclusion High scores of mutant EGFR, Napsin-A positivity, TTF-1 positivity, lower Ki67 index, and lepidic pattern were favorable predictors for TKI therapy in patients with advanced lung adenocarcinoma. PMID:26848271

  5. Comprehensive Molecular Structure of the Eukaryotic Ribosome

    PubMed Central

    Taylor, Derek J.; Devkota, Batsal; Huang, Andrew D.; Topf, Maya; Narayanan, Eswar; Sali, Andrej; Harvey, Stephen C.; Frank, Joachim

    2009-01-01

    Despite the emergence of a large number of X-ray crystallographic models of the bacterial 70S ribosome over the past decade, an accurate atomic model of the eukaryotic 80S ribosome is still not available. Eukaryotic ribosomes possess more ribosomal proteins and ribosomal RNA than bacterial ribosomes, which are implicated in extra-ribosomal functions in the eukaryotic cells. By combining cryo-EM with RNA and protein homology modeling, we obtained an atomic model of the yeast 80S ribosome complete with all ribosomal RNA expansion segments and all ribosomal proteins for which a structural homolog can be identified. Mutation or deletion of 80S ribosomal proteins can abrogate maturation of the ribosome, leading to several human diseases. We have localized one such protein unique to eukaryotes, rpS19e, whose mutations are associated with Diamond-Blackfan anemia in humans. Additionally, we characterize crucial and novel interactions between the dynamic stalk base of the ribosome with eukaryotic elongation factor 2. PMID:20004163

  6. Optical properties of Cr3+ -doped oxides: Different behavior of two centers in alexandrite

    NASA Astrophysics Data System (ADS)

    García-Lastra, J. M.; Aramburu, J. A.; Barriuso, M. T.; Moreno, M.

    2006-09-01

    This work is aimed at explaining the different color exhibited by the two Cr3+ centers in the alexandrite gemstone as well as ruby and emerald. Although the average Cr3+-O2- distance in ruby, emerald, and the Cs center in alexandrite is known to be practically the same, it is shown that the different values of the ligand field parameter 10Dq of the four Cr3+ centers mainly come from the electrostatic potential of the rest of lattice ions, VR(r) , seen by the CrO69- complex where active electrons are localized. This VR(r) potential, which strongly depends on the point symmetry group around the impurity, leads to an additional contribution to 10Dq not considered in the traditional ligand field theory. While for the Cs center (10Dq=2.19eV) and ruby (10Dq=2.24eV) , VR(r) has a similar shape along any Cr3+-O2- direction this is no longer true for the Ci center in alexandrite where the highest 10Dq value (equal to 2.53eV ) is measured.

  7. Hydrogenated fullerenes dimer, peanut and capsule: An atomic comparison

    NASA Astrophysics Data System (ADS)

    EL-Barbary, A. A.

    2016-04-01

    Hydrogenated fullerenes are detected in the Universe in space but their identification is still unsolved task. Therefore, this paper provides useful information about hydrogenated fullerenes (dimer, peanut and capsule) using DFT method at the B3LYP/6-31G(d) level of theory. The stability, geometric structures, hydrogen adsorption energies and NMR chemical shifts are calculated. The results show that the energy of most stable isomer of C118 dimer is lower than the energies sum of C60 and C58 cages by 1.77 eV and the energy per carbon atom of C144 capsule is more stable than C60 cage by 126.98 meV. Also, endohedral Ti-doped C118 dimer and C128 peanut are found to be most stable structures than exohedral Ti-doped C118 dimer and C128 peanut by 2.19 eV/Ti and 3.52 eV/Ti, respectively. The hydrogenation process is found to be enhanced (especially at the caps) for endohedral Ti-doped C118 dimer and C128 peanut through electronic surface modifications. The most active hydrogenation sites are selected and it is found that the most stable hydrogenation sites are Houts1 and Houts3 for fullerenes and endohedral Ti-doped fullerenes, respectively.

  8. Following solar activity with geomagnetic and cosmic-ray ground-based stations in the Iberian Peninsula region

    NASA Astrophysics Data System (ADS)

    Villasante-Marcos, Victor; José Blanco, Juan; Miquel Torta, Joan; Catalán, Manuel; Ribeiro, Paulo; Morozova, Anna; Tordesillas, José Manuel; Solé, Germán; Gomis-Moreno, Almudena

    2016-04-01

    The Iberian Peninsula is located in the South-West of Europe between 36°00' N and 43°47' N and between 9°29' W and 3°19' E. There are four Geomagnetic Observatories currently operative in this area devoted to the observation of the Earth's magnetic field: Observatori de l'Ebre (NE Spain); Observatorio de San Pablo de los Montes (central Spain); Observatorio de San Fernando (southern Spain); Observatório de Coimbra (central Portugal); plus another one, Observatorio de Güímar, in Tenerife (Canary Islands, Spain). There is also one neutron monitor located in Guadalajara (central Spain; 40°38' N, 3°9' W at 708 m asl) continuously measuring the arrival of cosmic rays to the Earth's surface. In this work we show combined observations of these six stations during events caused by solar activity. We analyze them looking for differences that could imply extremely local effects caused by the response of the Earth's magnetosphere and ionosphere to solar activity.

  9. Importance of anisotropic Coulomb interaction in LaMnO3

    NASA Astrophysics Data System (ADS)

    Mellan, Thomas A.; Corà, Furio; Grau-Crespo, Ricardo; Ismail-Beigi, Sohrab

    2015-08-01

    In low-temperature antiferromagnetic LaMnO3, strong and localized electronic interactions among Mn 3 d electrons prevent a satisfactory description from standard local density and generalized gradient approximations in density functional theory calculations. Here, we show that the strong on-site electronic interactions are described well only by using direct and exchange corrections to the intraorbital Coulomb potential. Only DFT + U calculations with explicit exchange corrections produce a balanced picture of electronic, magnetic, and structural observables in agreement with experiment. To understand the reason, a rewriting of the functional form of the + U corrections is presented that leads to a more physical and transparent understanding of the effect of these correction terms. The approach highlights the importance of Hund's coupling (intraorbital exchange) in providing anisotropy across the occupation and energy eigenvalues of the Mn d states. This intraorbital exchange is the key to fully activating the Jahn-Teller distortion, reproducing the experimental band gap and stabilizing the correct magnetic ground state in LaMnO3. The best parameter values for LaMnO3 within the DFT (PBEsol) + U framework are determined to be U =8 eV and J =1.9 eV.

  10. Ab initio study of semiconductor atoms impurities in zigzag edge (10,0) carbon nanotubes

    SciTech Connect

    Muttaqien, Fahdzi Suprijadi

    2015-04-16

    The substitutional impurities in zigzag edge (10,0) carbon nanotubes have been studied by using first principles calculations. Silicon (Si), gallium (Ga), and arsenic (As) atom have been chosen as semiconductor based-atom for replacing carbon atoms in CNT’s surface. The silicon atom changes the energy gap of pristine zigzag (10,0) CNT, it is 0.19 eV more narrow than that of pristine CNT. Geometrically, the silicon atom creates sp{sup 3} bond with three adjacent carbon atoms, where the tetrahedral form of its sp{sup 3} bond is consisted of free unoccupied state. The silicon atom does not induce magnetism to zigzag CNT. Due to gallium (Ga) and arsenic (As) atom substitution, the zigzag CNT becomes metallic and has magnetic moment of 1 µ{sub B}. The valance and conduction band are crossed each other, then the energy gap is vanished. The electronic properties of GaAs-doped CNT are dominantly affected by gallium atom and its magnetic properties are dominantly affected by arsenic atom. These results prove that the CNT with desired properties can be obtained with substitutional impurities without any giving structural defect.

  11. A genetic basis for the inviability of hybrids between sibling species of Drosophila

    SciTech Connect

    Hutter, P. ); Roote, J.; Ashburner, M. )

    1990-04-01

    An X-ray induced mutation of Drosophila melanogaster whose only known effect is the rescue of otherwise lethal interspecific hybrids has been characterized. This mutation, Hmr, maps to 1-31.84 (9D1-9E4). Hmr may be the consequence of a P element insertion. It rescues hybrid males from the cross of D. melanogaster females to males of its three sibling species, D. simulans, D. mauritiana and D. sechellia. This rescue is recessive, since hybrid males that carry both Hmr and a duplication expected to be Hmr{sup +} are not rescued. Hmr also rescues the otherwise inviable female hybrids from the cross of compound-X D. melanogaster females to males of its sibling species. This rescue is also recessive, since a compound-X heterozygous for Hmr does not rescue. Another mutation, discovered on the In(1)AB chromosome of D. melanogaster, is also found to rescue normally inviable species hybrids: unlike Hmr, however, In(1)AB rescues hybrid females from the cross of In(1)AB/Y males to sibling females, as well as hybrid males from the cross of In(1)AB females to sibling males. These data are interpreted on the basis of a model for the genetic basis of hybrid inviability of complementary genes.

  12. Low-energy-electron stimulated desorption of metastable particles from condensed N{sub 2} and CO

    SciTech Connect

    Shi, H.; Cloutier, P.; Sanche, L.

    1995-08-15

    The impact of low-energy electrons (7--19 eV, {Delta}{ital E}=60 meV) is found to induce desorption of metastable particles (N{sub 2}{sup *} and CO{sup *}) from condensed multilayer N{sub 2} and CO films. For N{sub 2} films, the yield function of the metastable-particle signal, which shows two regions (below and above 11 eV) of large intensity difference, is assigned to excitations to the valence state {ital B}{sup 3}{Pi}{sub {ital g}} and to the Rydberg state {ital E}{sup 3}{Sigma}{sub {ital g}}{sup +}, respectively. Desorption of N{sub 2}{sup *} above 11 eV is believed to be due to the repulsive interaction between the excited molecules and the solid surface. The desorption yield of CO{sup *}, which is much weaker than that for N{sub 2}{sup *}, is discussed in terms of vibrational energy transfer from the vibrational excited {ital a}{prime}{sup 3}{Sigma}{sup +} state.

  13. Development of epitaxial AlxSc1-xN for artificially structured metal/semiconductor superlattice metamaterials

    SciTech Connect

    Sands, Timothy D.; Stach, Eric A.; Saha, Bivas; Saber, Sammy; Naik, Gururaj V.; Boltasseva, Alexandra; Kvam, Eric P.

    2015-02-01

    Epitaxial nitride rocksalt metal/semiconductor superlattices are emerging as a novel class of artificially structured materials that have generated significant interest in recent years for their potential application in plasmonic and thermoelectric devices. Though most nitride metals are rocksalt, nitride semiconductors in general have hexagonal crystal structure. We report rocksalt aluminum scandium nitride (Al,Sc)N alloys as the semiconducting component in epitaxial rocksalt metal/semiconductor superlattices. The AlxSc1-xN alloys when deposited directly on MgO substrates are stabilized in a homogeneous rocksalt (single) phase when x < 0.51. Employing 20 nm TiN as a seed layer on MgO substrates, the homogeneity range for stabilizing the rocksalt phase has been extended to x < 0.82 for a 120 nm film. The rocksalt AlxSc1-xN alloys show moderate direct bandgap bowing with a bowing parameter, B = 1.41 ± 0.19 eV. The direct bandgap of metastable rocksalt AlN is extrapolated to be 4.70 ± 0.20 eV. The tunable lattice parameter, bandgap, dielectric permittivity, and electronic properties of rocksalt AlxSc1-xN alloys enable high quality epitaxial rocksalt metal/AlxSc1-xN superlattices with a wide range of accessible metamaterials properties.

  14. Correlation of the highest-energy cosmic rays with the positions of nearby active galactic nuclei

    SciTech Connect

    Collaboration, The Pierre auger

    2007-12-01

    Data collected by the Pierre Auger Observatory provide evidence for anisotropy in the arrival directions of the cosmic rays with the highest energies, which are correlated with the positions of relatively nearby active galactic nuclei (AGN) [1]. The correlation has maximum significance for cosmic rays with energy greater than {approx} 6 x 10{sup 19} eV and AGN at a distance less than {approx} 75 Mpc. We have confirmed the anisotropy at a confidence level of more than 99% through a test with parameters specified a priori, using an independent data set. The observed correlation is compatible with the hypothesis that cosmic rays with the highest energies originate from extra-galactic sources close enough so that their flux is not significantly attenuated by interaction with the cosmic background radiation (the Greisen-Zatsepin-Kuzmin effect). The angular scale of the correlation observed is a few degrees, which suggests a predominantly light composition unless the magnetic fields are very weak outside the thin disk of our galaxy. Our present data do not identify AGN as the sources of cosmic rays unambiguously, and other candidate sources which are distributed as nearby AGN are not ruled out. We discuss the prospect of unequivocal identification of individual sources of the highest-energy cosmic rays within a few years of continued operation of the Pierre Auger Observatory.

  15. Photoelectron spectroscopic and density functional theoretical studies of the 2'-deoxycytidine homodimer radical anion.

    PubMed

    Storoniak, Piotr; Rak, Janusz; Ko, Yeon Jae; Wang, Haopeng; Bowen, Kit H

    2013-08-21

    The intact (parent) 2'-deoxycytidine homodimer anion, (dC)2 (●-), was generated in the gas phase (in vacuo) using an infrared desorption∕photoemission source and its photoelectron spectrum was recorded using a pulsed, magnetic bottle photoelectron spectrometer. The photoelectron spectrum (PES) revealed a broad peak with the maximum at an electron binding energy between 1.6 and 1.9 eV and with a threshold at ∼1.2 eV. The relative energies and vertical detachment energies of possible anion radicals were calculated at the B3LYP/6-31++G(∗∗) level of theory. The most stable anion radicals are the complexes involving combinations of the sugar[middle dot][middle dot][middle dot]base and base[middle dot][middle dot][middle dot]base interactions. The calculated adiabatic electron affinities and vertical detachment energies of the most stable (dC)2 (●-) anions agree with the experimental values. In contrast with previous experimental-computational studies on the anionic complexes involving nucleobases with various proton-donors, the electron-induced proton transferred structures of (dC)2 (●-) are not responsible for the shape of PES. PMID:23968113

  16. Photoelectron spectroscopic and density functional theoretical studies of the 2'-deoxycytidine homodimer radical anion

    NASA Astrophysics Data System (ADS)

    Storoniak, Piotr; Rak, Janusz; Ko, Yeon Jae; Wang, Haopeng; Bowen, Kit H.

    2013-08-01

    The intact (parent) 2'-deoxycytidine homodimer anion, (dC)2•-, was generated in the gas phase (in vacuo) using an infrared desorption/photoemission source and its photoelectron spectrum was recorded using a pulsed, magnetic bottle photoelectron spectrometer. The photoelectron spectrum (PES) revealed a broad peak with the maximum at an electron binding energy between 1.6 and 1.9 eV and with a threshold at ˜1.2 eV. The relative energies and vertical detachment energies of possible anion radicals were calculated at the B3LYP/6-31++G** level of theory. The most stable anion radicals are the complexes involving combinations of the sugar...base and base...base interactions. The calculated adiabatic electron affinities and vertical detachment energies of the most stable (dC)2•- anions agree with the experimental values. In contrast with previous experimental-computational studies on the anionic complexes involving nucleobases with various proton-donors, the electron-induced proton transferred structures of (dC)2•- are not responsible for the shape of PES.

  17. Schizophrenia Gene Expression Profile Reverted to Normal Levels by Antipsychotics

    PubMed Central

    Crespo-Facorro, Benedicto; Prieto, Carlos

    2015-01-01

    Background: Despite the widespread use of antipsychotics, little is known of the molecular bases behind the action of antipsychotic drugs. A genome-wide study is needed to characterize the genes that affect the clinical response and their adverse effects. Methods: Here we show the analysis of the blood transcriptome of 22 schizophrenia patients before and after medication with atypical antipsychotics by next-generation sequencing. Results: We found that 17 genes, among the 21 495 genes analyzed, have significantly-altered expression after medication (p-value adjusted [Padj] <0.05). Six genes (ADAMTS2, CD177, CNTNAP3, ENTPD2, RFX2, and UNC45B) out of the 17 are among the 200 genes that we characterized with differential expression in a previous study between antipsychotic-naïve schizophrenia patients and controls (Sainz et al., 2013). This number of schizophrenia-altered expression genes is significantly higher than expected by chance (Chi-test, Padj 1.19E-50), suggesting that at least part of the antipsychotic beneficial effects is exerted by modulating the expression of these genes. Interestingly, all six of these genes were overexpressed in patients and reverted to control levels of expression after treatment. We also found a significant enrichment of genes related to obesity and diabetes, known adverse affects of antipsychotics. Conclusions: These results may facilitate understanding of unknown molecular mechanisms behind schizophrenia symptoms and the molecular mechanisms of antipsychotic drugs. PMID:25522406

  18. Direct experimental evidence for a metastable state of D/sub 2/F, an analogue of D/sub 3/O

    SciTech Connect

    Raksit, A.B.; Jeon, S.J.; Porter, R.F.

    1986-05-22

    The D/sub 2/F radical has been studied by a combination of neutralized ion beam and charge stripping techniques. Neutrals formed by D/sub 2/SF/sup +//Na charge exchange are observed in metastable and dissociative states. The lifetime of metastable D/sub 2/F is greater than 0.4 ..mu..s. Metastability is not observed for HDF or H/sub 2/F. The dissociative state of D/sub 2/F releases about 1.9 eV of kinetic energy in its fragmentation products (DF + D). The vertical electron affinity of H/sub 2/F/sup +/ is calculated to be 6.6 +- 0.2 eV. The possibility of observing an emission continuum from electronically excited H/sub 2/F formed by H/sub 2/F/sup +//K charge exchange is suggested. Similarities in the mass spectra of D/sub 2/F and the isoelectronic D/sub 3/O radical are indicated.

  19. High-Energy Density science at the Linac Coherent Light Source

    DOE PAGESBeta

    Glenzer, S. H.; Fletcher, L. B.; Hastings, J. B.

    2016-03-01

    The Matter in Extreme Conditions end station at the Linac Coherent Light Source holds great promise for novel pump-probe experiments to make new discoveries in high- energy density science. Recently, our experiments have demonstrated the first spectrally- resolved measurements of plasmons using a seeded 8-keV x-ray laser beam. Forward x-ray Thomson scattering spectra from isochorically heated solid aluminum show a well-resolved plasmon feature that is down-shifted in energy by 19 eV from the incident 8 keV elastic scattering feature. In this spectral range, the simultaneously measured backscatter spectrum shows no spectral features indicating observation of collective plasmon oscillations on amore » scattering length comparable to the screening length. Moreover, this technique is a prerequisite for Thomson scattering measurements in compressed matter where the plasmon shift is a sensitive function of the free electron density and where the plasmon intensity provides information on temperature.« less

  20. Unusual Changes in Electronic Band-Edge Energies of the Nanostructured Transparent n-Type Semiconductor Zr-Doped Anatase TiO2 (Ti1-xZrxO2; x < 0.3).

    PubMed

    Mieritz, Daniel G; Renaud, Adèle; Seo, Dong-Kyun

    2016-07-01

    By the establishment of highly controllable synthetic routes, electronic band-edge energies of the n-type transparent semiconductor Zr-doped anatase TiO2 have been studied holistically for the first time up to 30 atom % Zr, employing powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen gas sorption measurements, UV/vis spectroscopies, and Mott-Schottky measurements. The materials were produced through a sol-gel synthetic procedure that ensures good compositional homogeneity of the materials, while introducing nanoporosity in the structure, by achieving a mild calcination condition. Vegard's law was discovered among the homogeneous samples, and correlations were established between the chemical compositions and optical and electronic properties of the materials. Up to 20% Zr doping, the optical energy gap increases to 3.29 eV (vs 3.19 eV for TiO2), and the absolute conduction band-edge energy increases to -3.90 eV (vs -4.14 eV). The energy changes of the conduction band edge are more drastic than what is expected from the average electronegativities of the compounds, which may be due to the unnatural coordination environment around Zr in the anatase phase. PMID:27332108

  1. Non-radiative carrier recombination mechanism in the InGaAs/GaAsP strain-balanced quantum well solar cells with different number of stacks by using a piezoelectric photothermal method

    NASA Astrophysics Data System (ADS)

    Fukuyama, Atsuhiko; Nakano, Yosuke; Aihara, Taketo; Fujii, Hiroaki; Sugiyama, Masakazu; Nakano, Yoshiaki; Ikari, Tetsuo

    2012-10-01

    To optimize the multiple quantum well (QW) structure of the strain-balanced InGaAs/GaAsP inserted into GaAs p-i-n solar cell, carrier escaping process from QW, carrier radiative and non-radiative recombination processes in QW were investigated by using surface photovoltage (SPV), photoluminescence (PL) and piezoelectric photothermal (PPT) spectroscopies, respectively. Distinctive peaks at 1.19 eV were observed for all spectra below the bandgap of GaAs substrate (1.42 eV) and concluded that the peak was arisen from the excitonic transitions associated between the 1st order subbband in QWs. Although the optical absorption intensity of this transition was proportional to the number of QW stacks, SPV and PPT signals showed saturation above the QW stacks of 20. Band diagram calculation showed that an entire region of 10-stacked QWs was located in the flat band potential area, whereas a part of 20-stacked QWs was placed in an internal electric field. It was then suggested that the potential barrier height of 20-stacked QWs is small than that of 10-stacked QW.

  2. A study of the correlation of EHE cosmic rays with Gamma Ray Bursts

    SciTech Connect

    Takahashi, Yoshiyuki

    1998-06-15

    A study of space angles and temporal spacing was made for extremely-high energy (EHE) cosmic ray events to see if there are any correlation with Gamma Ray Bursts (GRB's) recorded by the BATSE experiment on the Compton Gamma Ray Observatory. The results on the most generic correlation using all the recorded GRB's and EHECR's show no significant correlation. Nevertheless, the highest-energy cosmic ray ''pair'' events observed by the AGASA experiments appear to be correlated with the very high fluence GRB's. Some basis to form a GRB and a fireball is discussed. Empirical analysis of the GRB events strongly implied that the photonic field energy density in the source region should have exceeded the electric energy density of Schwinger field. A possible generation of an initial GRB, its fireball and relativistic shocks therein, is considered in terms of Schwinger field generated by radiation pressure of transient, high luminosity photons provided by collective nuclear collisions of neutron matter. Acceleration of electrons, and some protons, may be possible in the radial electrostatic Schwinger field. Ultra-relativistic shocks might also accelerate particles to certain high energies ({gamma}{<=}10{sup 12{center_dot}}{sup 15}). Neutral secondaries, including gamma rays, neutrinos, ''strangelets,'' and Farrar's SUSY S{sub 0} particles, are discussed as plausible EHECR pair candidates from GRB fireballs. The OWL/AIRWATCH may be able to explore them from 4x10{sup 19} eV to well beyond 10{sup 21} eV.

  3. Simulated Performance of the Orbiting Wide-angle Light Collectors (OWL) Experiment

    NASA Technical Reports Server (NTRS)

    Krizmanic, J. F.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    The Orbiting Wide-angle Light collectors (OWL) experiment is in NASA's mid-term strategic plan and will stereoscopically image, from equatorial orbit, the air fluorescence signal generated by airshowers induced by the ultrahigh energy (E greater than few x 10(exp 19) eV) component of the cosmic radiation. The use of a space-based platform enables an extremely large event acceptance aperture and thus will allow a high statistics measurement of these rare events. Detailed Monte Carlo simulations are required to quantify the physics potential of the mission as well as optimize the instrumental parameters. This paper reports on the results of the GSFC Monte Carlo simulation for two different, OWL instrument baseline designs. These results indicate that, assuming a continuation of the cosmic ray spectrum (theta approximately E(exp -2.75), OWL could have an event rate of 4000 events/year with E greater than or equal to 10(exp 20) eV. Preliminary results, based upon these Monte Carlo simulations, indicate that events can be accurately reconstructed in the detector focal plane arrays for the OWL instrument baseline designs under consideration.

  4. From clusters to fibers: Parameters for discontinuous para-hexaphenylene thin film growth

    SciTech Connect

    Kankate, Laxman; Balzer, Frank; Niehus, Horst; Rubahn, Horst-Guenter

    2008-02-28

    All relevant steps of discontinuous thin film growth of para-hexaphenylene on muscovite mica (0 0 1) from wetting layer over small and large clusters to nanofibers are observed and investigated in detail by a combined polarized fluorescence and atomic force microscopy study. From a variation of film thickness and surface temperature, we determine effective activation energies for cluster growth of 0.17 eV, for nanofiber length growth of 0.46 eV, for width growth of 0.19 eV, and for height growth of 0.07 eV. The corresponding exponential prefactors for the nanofiber growth are 1x10{sup 9}, 6x10{sup 4}, and 3x10{sup 2} nm. Polarized fluorescence studies reveal that nanofibers grow along the grooves of the mica surface and that they do not change direction if they cross an even number of mica surface steps, while they change direction by 120 deg. for an odd number of steps. These results are taken as an input for a model of the unidirectional growth process on mica. Absolute parameters allowing one to grow nanofibers of predetermined morphology via organic molecular beam epitaxy are also given.

  5. Single crystal growth and enhancing effect of glycine on characteristic properties of bis-thiourea zinc acetate crystal

    NASA Astrophysics Data System (ADS)

    Anis, Mohd; Muley, G. G.

    2016-08-01

    A single crystal of glycine-doped bis-thiourea zinc acetate (G-BTZA) with a dimension of 15 × 6 × 4 mm3 has been grown using the slow solution evaporation technique. The structural parameters of the crystals were determined using the single crystal XRD technique. The increase in optical transparency of the doped BTZA crystal was ascertained in the range of 200 to 900 nm using UV–visible spectral analysis. The improved optical band gap of the G-BTZA crystal is found to be 4.19 eV, and vital optical constants have been calculated using the transmittance data. The influence of glycine on the mechanical parameters of the BTZA crystal has been investigated via microhardness studies. The thermal stability of pure and doped BTZA crystals has been determined by employing the thermogravimetric and differential thermal analysis technique. The improvement in the dielectric properties of the BTZA crystal after the addition of glycine has been evaluated in a temperature range of 30 to 120 °C at a frequency of 100 KHz. The SHG efficiency of the glycine-doped BTZA crystal is found to be much higher than KDP and BTZA crystal material in a Kurtz–Perry powder analysis.

  6. Structural and electronic properties of free standing one-sided and two-sided hydrogenated silicene: A first principle study

    SciTech Connect

    Mohan, Brij Kumar, Ashok Ahluwalia, P. K.

    2014-04-24

    We performed first-principle study of the structural and electronic properties of two-dimensional hydrogenated silicene for two configurations; one is hydrogenation along one side of silicene sheet and second is hydrogenation in both sides of silicene sheet. The one-side hydrogenated silicene is found stable at planar geometry while increased buckling of 0.725 Å is found for both-side hydrogenated silicene. The result shows that the hydrogenation occupy the extended π-bonding network of silicene, and thus it exhibits semi-conducting behaviour with a band gap of 1.77 eV and 2.19 eV for one-side hydrogenated silicene and both-side hydrogenated silicene respectively. However, both-side hydrogenated silicene of binding energy 4.56 eV is more stable than one-side hydrogenated silicene of binding energy 4.30 eV, but experimentally silicene is synthesized on substrates which interacts one side of silicene layer and only other side is available for H-atoms. Therefore, practically one-side hydrogenation is also important.

  7. Support effect in oxide catalysis: methanol oxidation on vanadia/ceria.

    PubMed

    Kropp, Thomas; Paier, Joachim; Sauer, Joachim

    2014-10-15

    Density functional theory is used for periodic models of monomeric vanadia species deposited on the CeO2(111) surface to study dissociative adsorption of methanol and its subsequent dehydrogenation to formaldehyde. Dispersion-corrected PBE+U calculations are performed and compared with HSE and B3LYP results. Dissociative adsorption of methanol at different sites on VO2·CeO2(111) is highly exothermic with adsorption energies of 1.8 to 1.9 eV (HSE+D). Two relevant pathways for desorption of formaldehyde are found with intrinsic barriers for the redox step of 1.0 and 1.4 eV (HSE+D). The calculated desorption temperatures (370 and 495 K) explain the peaks observed in temperature-programmed desorption experiments. Different sites of the supported catalyst system are involved in the two pathways: (i) methanol can chemisorb on the CeO2 surface filling a so-called pseudovacancy and the H atom is transferred to an V-O-Ce interphase bond or (ii) CH3OH may chemisorb at the V-O-Ce interphase bond and form a V-OCH3 species from which H is transferred to the ceria surface, providing evidence for true cooperativity. In both cases, ceria is directly involved in the redox process, as two electrons are accommodated in Ce f states forming two Ce(3+) ions whereas vanadium remains fully oxidized (V(5+)). PMID:25275568

  8. A study of optothermal and AC impedance properties of Cr-doped Mn{sub 3}O{sub 4} sprayed thin films

    SciTech Connect

    Larbi, T.; Amara, A.; Ben Said, L.; Ouni, B.; Haj Lakhdar, M.; Amlouk, M.

    2015-10-15

    Highlights: • Outlining adequacy an original combination of several characterization means. • Structural, optical, thermal and electrical properties have been studied. • Opto- thermal analysis shows that band gap can be tuned through Cr doping. • Outlining physical properties for an eventual development of sensing components. - Abstract: Chrome-doped Mn{sub 3}O{sub 4} thin films were grown on the glass substrates by the spray pyrolysis technique at 350 °C. XRD diffraction and Raman spectroscopy analysis revealed that all samples have tetragonal spinel structure with a preferred orientation along the direction (1 0 1). Absorption coefficient has been measured using both transmission and mirage effect. The band gap energy decreases from 2.2 to 1.9 eV with Cr content while Urbach energy value increases from 354 to 473 meV. Also, thermal conductivity was evaluated. Finally, physical properties have been evaluated and discussed in terms of alteration of the band gap edges, electrical patterns and mirage effect.

  9. X{sub max}{sup μ} vs. N{sup μ} from extensive air showers as estimator for the mass of primary UHECR's. Application for the Pierre Auger Observatory

    SciTech Connect

    Arsene, Nicusor; Sima, Octavian

    2015-02-24

    We study the possibility of primary mass estimation for Ultra High Energy Cosmic Rays (UHECR's) using the X{sub max}{sup μ} (the height where the number of muons produced on the core of Extensive Air Showers (EAS) is maximum) and the number N{sup μ} of muons detected on ground. We use the 2D distribution - X{sub max}{sup μ} against N{sup μ} in order to find its sensitivity to the mass of the primary particle. For that, we construct a 2D Probability Function Prob(p,Fe | X{sub max}{sup μ}, N{sup μ}) which estimates the probability that a certain point from the plane (X{sub max}{sup μ}, N{sup μ}) corresponds to a shower induced by a proton, respectively an iron nucleus. To test the procedure, we analyze a set of simulated EAS induced by protons and iron nuclei at energies of 10{sup 19}eV and 20° zenith angle with CORSIKA. Using the Bayesian approach and taking into account the geometry of the infill detectors from the Pierre Auger Observatory, we observe an improvement in the accuracy of the primary mass reconstruction in comparison with the results obtained using only the X{sub max}{sup μ} distributions.

  10. Optical depth of the Universe to ultrahigh energy cosmic ray scattering in the magnetized large scale structure

    SciTech Connect

    Kotera, Kumiko; Lemoine, Martin

    2008-06-15

    This paper provides an analytical description of the transport of ultrahigh energy cosmic rays in an inhomogeneously magnetized intergalactic medium. The latter is modeled as a collection of magnetized scattering centers, such as radio cocoons, magnetized galactic winds, clusters or magnetized filaments of large scale structure, with negligible magnetic fields in between. Magnetic deflection is no longer a continuous process, it is rather dominated by scattering events. We study the interaction between high-energy cosmic rays and the scattering agents. We then compute the optical depth of the Universe to cosmic ray scattering and discuss the phenomenological consequences for various source scenarios. For typical parameters of the scattering centers, the optical depth is greater than unity at 5x10{sup 19} eV, but the total angular deflection is smaller than unity. One important consequence of this scenario is the possibility that the last scattering center encountered by a cosmic ray be mistaken with the source of this cosmic ray. In particular, we suggest that part of the correlation recently reported by the Pierre Auger Observatory may be affected by such delusion: this experiment may be observing in part the last scattering surface of ultrahigh energy cosmic rays rather than their source population. Since the optical depth falls rapidly with increasing energy, one should probe the arrival directions of the highest energy events beyond 10{sup 20} eV on an event by event basis to circumvent this effect.

  11. Supercontinuum spatial modulation spectroscopy: Detection and noise limitations

    NASA Astrophysics Data System (ADS)

    McDonald, M. P.; Vietmeyer, F.; Aleksiuk, D.; Kuno, M.

    2013-11-01

    Supercontinuum spatial modulation spectroscopy is a facile tool for conducting single molecule/particle extinction spectroscopy throughout the visible and near infrared (420-1100 nm). The technique's capabilities are benchmarked using individual Au nanoparticles (NPs) as a standard since they are well studied and display a prominent plasmon resonance in the visible. Extinction spectra of individual Au NPs with diameters (d) ranging from d ˜ 8 to 40 nm are resolved with extinction cross sections (σext) of σext ˜1 × 10-13-1 ×10-11 cm2. Corresponding signal-to-noise ratios range from ˜30 to ˜1400. The technique's limit of detection is determined to be 4.3 × 10-14 cm2 (4.3 nm2). To showcase supercontinuum spatial modulation spectroscopy's broader applicability, extinction spectra are acquired for other model systems, such as individual single-walled carbon nanotubes (SWCNTs) and CdSe nanowires. We show for the first time extinction spectra of individual (8,3) and (6,5) SWCNTs. For both chiralities, their E11 [(8,3) 1.30 eV (952 nm); (6,5) 1.26 eV (986 nm)] and E22 [(8,3) 1.86 eV (667 nm); (6,5) 2.19 eV (567 nm)] excitonic resonances are seen with corresponding cross sections of σext ˜ 10-13 cm2 μm-1.

  12. Magnetoresistance in Boron Carbide junctions

    NASA Astrophysics Data System (ADS)

    Day, Ellen; Sokolov, A.; Baruth, A.; Robertson, B. W.; Adenwalla, S.

    2007-03-01

    The properties of thin insulator layers are crucial to the performance of magnetic tunnel junctions. Commercial requirements are a device with a high tunnel magnetoresistance (TMR) with low cost and high stability. At present the vast majority of barriers are made from amorphous Al2O3 and crystalline MgO. The TMR value depends not only on the spin-dependent electronic structure of the electrodes, but on the metal-insulator interface. Oxide-type barriers may suffer from local vacancies and other type of defects, resulting in oxygen diffusion, making the TMR value unstable with time. We present TMR results obtained on a non-oxide barrier, boron carbide (B10C2) for applications in magnetic tunnel junctions. This low Z inorganic material can be grown by plasma enhanced chemical vapor deposition (PECVD) without pinholes in the ultra thin film regime. PECVD grown boron carbide is an excellent dielectric with resistivities in the range of 10^7 ohm-cm, with a band gap that can be adjusted from 0.7 eV to 1.9 eV by altering the boron to carbon ratio and to band gap values well above 2.7 eV by adding phosphorus. This creates a unique opportunity for experimental study of a broad spectrum of phenomena, related to the dielectric properties of the barrier.

  13. Bio-inspired ZnO nanoparticles from Ocimum tenuiflorum and their in vitro antioxidant activity

    NASA Astrophysics Data System (ADS)

    Sushma, N. John; Mahitha, B.; Mallikarjuna, K.; Raju, B. Deva Prasad

    2016-05-01

    Nanobiotechnology is emerging as a rapid growing field with its applications in nanoscience and technology for the purpose of built-up new materials at the nanoregime. Nanoparticles produced by plant extracts are more stable, and the rate of synthesis is faster than that in the case of other organisms. In this paper we report the biosynthesis of zinc oxide nanoparticles (ZnO NPs). Structural, morphological, particle size, and optical properties of the synthesized nanoparticles have been characterized by using UV-Vis spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscope, energy-dispersive X-ray spectroscopy, atomic-force microscopy, zeta potential, X-ray diffraction, and photoluminescence intensity. The UV-Vis spectrum showed an absorption peak at 380 nm that reflects surface plasmon resonance. The optical measurements were attributed to the band gap 3.19 eV at pH 12. The zeta potential value of -36.4 eV revealed the surface charge of green synthesized ZnO NPs. The antioxidant activity was estimated by both 1,1-diphenyl-2-picrylhydrazyl and reducing power assay. Green synthesized ZnO NPs showed maximum inhibition (65.23 %) and absorbance (0.6 a.u). This approach offers environmentally beneficial alternative by eliminating hazardous chemicals and promotes pollution prevention by the production of nanoparticles in their natural environment.

  14. Precise in-frame integration of exogenous DNA mediated by CRISPR/Cas9 system in zebrafish.

    PubMed

    Hisano, Yu; Sakuma, Tetsushi; Nakade, Shota; Ohga, Rie; Ota, Satoshi; Okamoto, Hitoshi; Yamamoto, Takashi; Kawahara, Atsuo

    2015-01-01

    The CRISPR/Cas9 system provides a powerful tool for genome editing in various model organisms, including zebrafish. The establishment of targeted gene-disrupted zebrafish (knockouts) is readily achieved by CRISPR/Cas9-mediated genome modification. Recently, exogenous DNA integration into the zebrafish genome via homology-independent DNA repair was reported, but this integration contained various mutations at the junctions of genomic and integrated DNA. Thus, precise genome modification into targeted genomic loci remains to be achieved. Here, we describe efficient, precise CRISPR/Cas9-mediated integration using a donor vector harbouring short homologous sequences (10-40 bp) flanking the genomic target locus. We succeeded in integrating with high efficiency an exogenous mCherry or eGFP gene into targeted genes (tyrosinase and krtt1c19e) in frame. We found the precise in-frame integration of exogenous DNA without backbone vector sequences when Cas9 cleavage sites were introduced at both sides of the left homology arm, the eGFP sequence and the right homology arm. Furthermore, we confirmed that this precise genome modification was heritable. This simple method enables precise targeted gene knock-in in zebrafish. PMID:25740433

  15. Determination of the basic optical parameters of ZnSnN(2).

    PubMed

    Deng, Fuling; Cao, Hongtao; Liang, Lingyan; Li, Jun; Gao, Junhua; Zhang, Hongliang; Qin, Ruifeng; Liu, Caichi

    2015-04-01

    Polycrystalline ZnSnN(2) thin films were successfully prepared by DC magnetron sputtering at room temperature. Both the as-deposited and annealed films showed n-type conduction, with electron concentration varying between 1.6×10(18) and 2.3×10(17)  cm(-3) and the maximum mobility of 3.98  cm(2)  V(-1) s(-1). The basic optical parameters such as the refraction index, extinction coefficient, and absorption coefficient were precisely determined through the spectroscopic ellipsometry measurement and analysis. The optical bandgap of the ZnSnN(2)films was calculated to around 1.9 eV, with the absorption coefficient greater than 10(4)  cm(-1) at wavelengths less than 845 nm. The easy-fabricated ZnSnN(2) possesses a sound absorption coefficient ranging from the ultraviolet through visible light and into the near-infrared, comparable to some typical photovoltaic materials such as GaAs, CdTe, and InP. PMID:25831313

  16. Segmentation and Classification of Nepal Earthquake Induced Landslides Using SENTINEL-1 Product

    NASA Astrophysics Data System (ADS)

    Kunwar, Saket

    2016-06-01

    On April 26, 2015, an earthquake of magnitude 7.8 on the Richter scale occurred, with epicentre at Barpak (28°12'20''N,84°44'19''E), Nepal. Landslides induced due to the earthquake and its aftershock added to the natural disaster claiming more than 9000 lives. Landslides represented as lines that extend from the head scarp to the toe of the deposit were mapped by the staff of the British Geological Survey and is available freely under Open Data Commons Open Database License(ODC-ODbL) license at the Humanitarian Data Exchange Program. This collection of 5578 landslides is used as preliminary ground truth in this study with the aim of producing polygonal delineation of the landslides from the polylines via object oriented segmentation. Texture measures from Sentinel-1a Ground Range Detected (GRD) Amplitude data and eigenvalue-decomposed Single Look Complex (SLC) polarimetry product are stacked for this purpose. This has also enabled the investigation of landslide properties in the H-Alpha plane, while developing a classification mechanism for identifying the occurrence of landslides.

  17. Measuring the mass of a sterile neutrino with a very short baseline reactor experiment

    SciTech Connect

    Latimer, D. C.; Escamilla, J.; Ernst, D. J.

    2007-04-15

    An analysis of the world's neutrino oscillation data, including sterile neutrinos, [M. Sorel, C. M. Conrad, and M. H. Shaevitz, Phys. Rev. D 70, 073004 (2004)] found a peak in the allowed region at a mass-squared difference {delta}m{sup 2} congruent with 0.9 eV{sup 2}. We trace its origin to harmonic oscillations in the electron survival probability P{sub ee} as a function of L/E, the ratio of baseline to neutrino energy, as measured in the near detector of the Bugey experiment. We find a second occurrence for {delta}m{sup 2} congruent with 1.9 eV{sup 2}. We point out that the phenomenon of harmonic oscillations of P{sub ee} as a function of L/E, as seen in the Bugey experiment, can be used to measure the mass-squared difference associated with a sterile neutrino in the range from a fraction of an eV{sup 2} to several eV{sup 2} (compatible with that indicated by the LSND experiment), as well as measure the amount of electron-sterile neutrino mixing. We observe that the experiment is independent, to lowest order, of the size of the reactor and suggest the possibility of a small reactor with a detector sitting at a very short baseline.

  18. Measurements of ion temperature and flow of pulsed plasmas produced by a magnetized coaxial plasma gun device using an ion Doppler spectrometer

    NASA Astrophysics Data System (ADS)

    Kitagawa, Y.; Sakuma, I.; Iwamoto, D.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2012-10-01

    It is important to know surface damage characteristics of plasma-facing component materials during transient heat and particle loads such as type I ELMs. A magnetized coaxial plasma gun (MCPG) device has been used as transient heat and particle source in ELM simulation experiments. Characteristics of pulsed plasmas produced by the MCPG device play an important role for the plasma material interaction. In this study, ion temperature and flow velocity of pulsed He plasmas were measured by an ion Doppler spectrometer (IDS). The IDS system consists of a light collection system including optical fibers, 1m-spectrometer and a 16 channel photomultiplier tube (PMT) detector. The IDS system measures the width and Doppler shift of HeII (468.58 nm) emission line with the time resolution of 1 μs. The Doppler broadened and shifted spectra were measured with 45 and 135 degree angles with respect to the plasmoid traveling direction. The observed emission line profile was represented by sum of two Gaussian components to determine the temperature and flow velocity. The minor component at around the wavelength of zero-velocity was produced by the stationary plasma. As the results, the ion velocity and temperature were 68 km/s and 19 eV, respectively. Thus, the He ion flow energy is 97 eV. The observed flow velocity agrees with that measured by a time of flight technique.

  19. Ab initio study of the positronation of the CaO and SrO molecules including calculation of annihilation rates.

    PubMed

    Buenker, Robert J; Liebermann, Heinz-Peter

    2012-07-15

    Ab initio multireference single- and double-excitation configuration interaction calculations have been performed to compute potential curves for ground and excited states of the CaO and SrO molecules and their positronic complexes, e(+)CaO, and e(+)SrO. The adiabatic dissociation limit for the (2)Σ(+) lowest states of the latter systems consists of the positive metal ion ground state (M(+)) and the OPs complex (e(+)O(-)), although the lowest energy limit is thought to be e(+)M + O. Good agreement is found between the calculated and experimental spectroscopic constants for the neutral diatomics wherever available. The positron affinity of the closed-shell X (1)Σ(+) ground states of both systems is found to lie in the 0.16-0.19 eV range, less than half the corresponding values for the lighter members of the alkaline earth monoxide series, BeO and MgO. Annihilation rates (ARs) have been calculated for all four positronated systems for the first time. The variation with bond distance is generally similar to what has been found earlier for the alkali monoxide series of positronic complexes, falling off gradually from the OPs AR value at their respective dissociation limits. The e(+)SrO system shows some exceptional behavior, however, with its AR value reaching a minimum at a relatively large bond distance and then rising to more than twice the OPs value close to its equilibrium distance. PMID:22522712

  20. Magnesium diffusion profile in GaN grown by MOVPE

    NASA Astrophysics Data System (ADS)

    Benzarti, Z.; Halidou, I.; Bougrioua, Z.; Boufaden, T.; El Jani, B.

    2008-07-01

    The diffusion of magnesium has been studied in GaN layers grown on sapphire substrate by atmospheric pressure metalorganic vapor-phase-epitaxy (MOVPE) in a "home-made" reactor. Secondary Ion Mass Spectroscopy (SIMS) was used to visualise the Mg profiles in two kinds of multi-sublayer GaN structures. One structure was grown with a variable flow of Ga precursor (TMG) and the second one with a variable growth temperature. In both cases, the Mg dopant precursor (Cp 2Mg) flow was kept constant. Using the second Fick's law to fit the experimental SIMS data, we have deduced an increasing then a saturating Mg diffusion coefficient versus the Mg concentration. Mg incorporation was found to get higher for lower growth rate, i.e. when TMG flow is reduced. Furthermore, based on the temperature-related behaviour we have found that the activation energy for Mg diffusion coefficient in GaN was 1.9 eV. It is suggested that Mg diffuses via substitutional sites.

  1. Hydroxyapatite-titanium interface reaction induced by keV electron irradiation

    NASA Astrophysics Data System (ADS)

    Torrisi, L.; Foti, G.

    1992-03-01

    Thin films of hydroxyapatite bioceramic, 5-50 Å in thickness, have been deposited on ion cleaned titanium surfaces to study the chemical-physical adhesion of metal-ceramic interfaces of biomedical devices (orthopaedic and dentistry prosthesis). Film deposition was performed in ultrahigh vacuum condition (10 -10 mbar) using 5 keV argon sputtering of hydroxyapatite matrix; the film thickness was measured in situ with Auger electron spectroscopy. The hydroxyapatite-titanium interface was irradiated with an electron beam of 0.5-5 keV energy and 0.2-2 A/cm 2 current density. During electron irradiation, Auger spectra show chemical shifts of phosphorus, titanium and oxygen peaks. The released electron energy induces modifications in the tetraedric phosphorus-oxygen groups with production of new chemical bonds between phosphorus, oxygen and titanium. Oxygen, for example, diffuses into the titanium interface forming titanium oxide. Chemical reactions induced by electron irradiation are driven by the metal-ceramic interface. Near the interface a strong and fast effect is observed while far from the interface a weak and slow effect occurs. Chemical reactions depend on the electron irradiation dose showing an inhibition threshold at about 10 19 e/cm 2 and, near the interface, a saturation condition at about 5 × 10 20 e/cm 2. Titanium-ceramic chemical reactions are inhibited if the substrate titanium surface is rich in oxide.

  2. Primary structure and functional scFv antibody expression of an antibody against the human protooncogen c-myc.

    PubMed

    Fuchs, P; Breitling, F; Little, M; Dübel, S

    1997-06-01

    The immunoglobulin heavy- and light-chain variable region (Vh and Vl) genes were isolated from Myc1-9E10 hybridoma cells, which secreted monoclonal antibody against human oncogen c-myc. The expression vector pOPE52-c-myc was constructed for the recombinant production in E. coli. A 30 kDa single chain fragment (scFv) expression product was found in the periplasmic space by SDS-PAGE and immunoblotting. A significant fraction was processed correctly as demonstrated with an antiserum recognizing the processed aminoterminus only. The specific binding of the scFv fragment to the peptide epitope of the maternal monoclonal antibody was demonstrated and the primary sequence of the variable regions was determined. Sequence comparison with previously published partial Vh and Vl sequences from this hybridoma cell line revealed a genetic heterogeneity for the light chain variable region. The potential use of this scFv as a new tool for detection and purification of tagged proteins, for adding costimulatory signals to the surface of cancer cells as well as for analyzing c-myc function in the living cell by cytoplasmic expression is discussed. PMID:9219032

  3. Light absorption and conversion in solar cell based on Si:O alloy

    NASA Astrophysics Data System (ADS)

    Scapellato, G. G.; Rubino, M.; Crupi, I.; Di Marco, S.; Simone, F.; Mirabella, S.

    2013-08-01

    Thin film Si:O alloys have been grown by plasma enhanced chemical vapor deposition, as intrinsic or highly doped (1 to 5 at. % of B or P dopant) layers. UV-visible/near-infrared spectroscopy revealed a great dependence of the absorption coefficient and of the optical gap (Eg) on the dopant type and concentration, as Eg decreases from 2.1 to 1.9 eV, for the intrinsic or highly p-doped sample, respectively. Thermal annealing up to 400 °C induces a huge H out-diffusion which causes a dramatic absorption increase and a reduction of Eg, down to less than 1.8 eV. A prototypal solar cell has been fabricated using a 400 nm thick, p-i-n structure made of Si:O alloy embedded within flat transparent conductive oxides. Preliminary electrical analyses show a photovoltaic (PV) effect with an open circuit voltage of 0.75 V and a spectral conversion efficiency blue-shifted in comparison to a-Si:H based cell, as expected since the higher Eg in Si:O alloy. These data are presented and discussed, suggesting Si:O alloy as promising material for PV device fabrication.

  4. Correlation between I (current)-V (voltage) characteristics and thermally stimulated depolarization current of Mn-doped BaTiO3 multilayer ceramic capacitor

    NASA Astrophysics Data System (ADS)

    Yoon, Seok-Hyun; Kim, Sang-Hyuk; Kim, Doo-Young

    2013-08-01

    I (Current)-V (voltage) characteristics of Mn-doped BaTiO3 multilayer ceramic capacitor were investigated. The increase of Mn concentration reduced the slope of current increase with increasing dc field and enhanced the dc field to the abrupt increase of current and thereby breakdown. Ohmic, Schottky, and Poole-Frenkel type conduction was successively observed with the increase of dc field in all specimens. The region of Child's law did not appear before breakdown, which suggests space charge limited (SCL) conduction with field enhanced trap barrier lowering. A peak of thermally stimulated depolarization current (TSDC) beyond 300 °C associated with trapped space charges appeared, which increased by the increase of Mn concentration. In addition, the peak intensity increased to a maximum value and then decreased again with increasing polarization dc field in TSDC measurement. Its activation energies were around 1.9 eV for all specimens, which is very close to the energy level for the ionization of Mn3+/Mn2+. These results experimentally demonstrate the role of the variable valence acceptor Mn as trapping center for injected charges, and the occurrence of field enhanced trap charge release, and therefore, the conduction mechanism can be described by the SCL model incorporating the Poole-Frenkel effect.

  5. Progress in ultra high energy neutrino experiments using radio techniques

    SciTech Connect

    Liu Jiali; Tiedt, Douglas

    2013-05-23

    Studying the source of Ultra High Energy Cosmic Ray (UHECR) can provide important clues on the understanding of UHE particle physics, astrophysics, and other extremely energetic phenomena in the universe. However, charged CR particles are deflected by magnetic fields and can not point back to the source. Furthermore, UHECR charged particles above the Greisen-Zatsepin-Kuzmin (GZK) cutoff (about 5 Multiplication-Sign 10{sup 19} eV) suffer severe energy loss due to the interaction with the Cosmic Microwave Background Radiation (CMBR). Consequently almost all the information carried by CR particles about their origin is lost. Neutrinos, which are neutral particles and have extremely weak interactions with other materials can arrive at the earth without deflection and absorption. Therefore UHE neutrinos can be traced back to the place where they are produced. Due to their weak interaction and ultra high energies (thus extremely low flux) the detection of UHE neutrinos requires a large collecting area and massive amounts of material. Cherenkov detection at radio frequency, which has long attenuation lengths and can travel freely in natural dense medium (ice, rock and salt et al), can fulfill the detection requirement. Many UHE neutrino experiments are being performed by radio techniques using natural ice, lunar, and salt as detection mediums. These experiments have obtained much data about radio production, propagation and detection, and the upper limit of UHE neutrino flux.

  6. Growth mechanism, structure and IR photoluminescence studies of indium nitride nanorods

    NASA Astrophysics Data System (ADS)

    Lan, Z. H.; Wang, W. M.; Sun, C. L.; Shi, S. C.; Hsu, C. W.; Chen, T. T.; Chen, K. H.; Chen, C. C.; Chen, Y. F.; Chen, L. C.

    2004-08-01

    High-quality single crystal indium nitride nanorods were grown on Si substrates by catalytic chemical vapor deposition. Both Raman and high resolution transmission electron microscopic analyses suggested that even a minute amount of oxygen, from the residual oxygen in the growth environment and/or native oxide on the Si, would effectively help the growth of InN nanorods. The In 2O 3 formed on Au nanoparticles helped dissolve nitrogen as a catalyst with the subsequent growth of InN nanorods. Variations in the apparent color and photoluminescence (PL) spectra of the InN nanorods were observed. For the optically brown InN nanorods that exhibited diameters in the range of 30-50 nm, the PL study showed a peak at 1.9 eV, the possible origins of which are discussed. In contrast, for the optically black InN nanorods that exhibited diameters in the range of 50-100 nm, the PL peak at approximately 0.766 eV measured at 20 K was attributed to band edge emission.

  7. Sensitivity of the reference evapotranspiration to key climatic variables in Shandong Province, China

    NASA Astrophysics Data System (ADS)

    Yang, Jialin; Liu, Chaoshun; Zhou, Cong

    2015-09-01

    The aim of this work was to predict responses of reference evapotranspiration (ETo) to perturbations of four climatic variables in Shandong province, China. For this purpose, ETo was estimated based on the FAO-56 Penman-Monteith equation, a non-dimensional relative sensitivity coefficient was employed. Climatic variables (i.e., daily air temperature, sunshine duration, wind speed and daily relative humidity) at 12 meteorological stations covering whole area (1960 to 2013) were collected firstly and used for the analysis. Results showed that ETo had positive sensitivities to air temperature, sunshine duration and wind speed, opposite to what were observed to relative humidity. The sensitivity of climatic parameters to ETo showed a decreasing trend: relative humidity> >sunshine duration>wind speed > air temperature. The sensitivity coefficients of different factors varied in time and space. From 1960 to 2013, the sensitivity coefficient of sunshine duration (Sn) showed a downward trend at a rate of (-4.3e-4)/a. The sensitivity coefficient of wind speed (SWS) and relative humidity (SRH) increased at a rate of (3.9e-4)/a and (1.9e-3)/a respectively, while the sensitivity coefficient of air temperature (ST) waved with a tiny decrease trend. The values of ST and Sn in southern were larger than in northern region. The values of SWS in southern and northeast region were smaller than that in the northern area. SRH in the central region was lower than other area, opposite to what were observed in coastal areas.

  8. Status of EXO-200

    SciTech Connect

    Ackerman, Nicole; /SLAC

    2011-12-06

    EXO-200 is the first phase of the Enriched Xenon Observatory (EXO) experiment, which searches for neutrinoless double beta decay in {sup 136}Xe to measure the mass and probe the Majorana nature of the neutrino. EXO-200 consists of 200 kg of liquid Xe enriched to 80% in {sup 136}Xe in an ultra-low background TPC. Energy resolution is enhanced through the simultaneous collection of scintillation light using Large Area Avalanche Photodiodes (LAAPD's) and ionization charge. It is being installed at the WIPP site in New Mexico, which provides a 2000 meter water-equivalent overburden. EXO-200 will begin taking data in 2009, with the expected two-year sensitivity to the half-life for neutrinoless double beta decay of 6.4 x 10{sup 25} years. According to the most recent nuclear matrix element calculations, this corresponds to an effective Majorana neutrino mass of 0.13 to 0.19 eV. It will also measure the two neutrino mode for the first time in {sup 136}Xe.

  9. First-Principles Study of Phosphorene and Graphene Heterostructure as Anode Materials for Rechargeable Li Batteries.

    PubMed

    Guo, Gen-Cai; Wang, Da; Wei, Xiao-Lin; Zhang, Qi; Liu, Hao; Lau, Woon-Ming; Liu, Li-Min

    2015-12-17

    There is a great desire to develop the high-efficient anodes materials for Li batteries, which require not only large capacity but also high stability and mobility. In this work, the phosphorene/graphene heterostructure (P/G) was carefully explored based on first-principles calculations. The binding energy of Li on the pristine phosphorene is relatively weak (within 1.9 eV), whereas the phosphorene/graphene heterostructure (P/G) can greatly improve the binding energy (2.6 eV) without affecting the high mobility of Li within the layers. The electronic structures show that the large Li adsorption energy and fast diffusion ability of the P/G origin from the interfacial synergy effect. Interestingly, the P/G also displays ultrahigh stiffness (Cac = 350 N/m, Czz = 464 N/m), which can effectively avoid the distortion of the pristine phosphorene after the insertion of lithium. Thus, P/G can greatly enhance the cycle life of the battery. Owing to the high capacity, good conductivity, excellent Li mobility, and ultrahigh stiffness, P/G is a very promising anode material in Li-ion batteries (LIBs). PMID:26623923

  10. Electrochromic properties of poly (1-(phenyl)-2,5-di(2-thienyl)-1H-pyrrole-co-3,4-ethylenedioxy thiophene) and its application in electrochromic devices

    NASA Astrophysics Data System (ADS)

    Tarkuc, S.; Sahmetlioglu, E.; Tanyeli, C.; Akhmedov, I. M.; Toppare, L.

    2008-06-01

    Electrochemical copolymerization of 1-(phenyl)-2,5-di(2-thienyl)-1H-pyrrole (PTP) with 3,4-ethylenedioxy thiophene (EDOT) was carried out in acetonitrile (AN)/NaClO4/LiClO4 (0.1 M) solvent-electrolyte couple via potentiodynamic electrolysis. Characterizations of the resulting copolymer were performed via cyclic voltammetry (CV), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and spectroelectrochemical analysis. Spectroelectrochemical analyses show that the copolymer of PTP with EDOT has an electronic band gap (due to π to π∗ transition) of 1.9 eV at 480 nm, with a claret red in the fully reduced form and a blue color in the fully oxidized form. Via kinetic studies, the optical contrast (ΔT %) was found to be 8% for P(PTP-co-EDOT). Results showed that the time required to reach 95% of the ultimate transmittance was 1.7 s for the copolymer. The P(PTP-co-EDOT) film was used to construct a dual type polymer electrochromic device (ECDs) with poly(3,4-ethylenedioxy thiophene) (PEDOT). Spectroelectrochemistry, electrochromic switching and open circuit memory of the device were investigated.

  11. Realization of a reversible switching in TaO2 polymorphs via Peierls distortion for resistance random access memory

    NASA Astrophysics Data System (ADS)

    Zhu, Linggang; Zhou, Jian; Guo, Zhonglu; Sun, Zhimei

    2015-03-01

    Transition-metal-oxide based resistance random access memory (RRAM) is a promising candidate for next-generation universal non-volatile memories. Searching and designing appropriate materials used in the memories becomes an urgent task. Here, a structure with the TaO2 formula was predicted using evolutionary algorithms in combination with first-principles calculations. This triclinic structure (T-TaO2) is both energetically and dynamically more favorable than the commonly believed rutile structure (R-TaO2). The metal-insulator transition (MIT) between metallic R-TaO2 and T-TaO2 (band gap: 1.0 eV) is via a Peierls distortion, which makes TaO2 a potential candidate for RRAM. The energy barrier for the reversible phase transition is 0.19 eV/atom and 0.23 eV/atom, respectively, suggesting low power consumption for the resistance switch. The present findings about the MIT as the resistance-switch mechanism in Ta-O system will stimulate experimental work to fabricate tantalum oxides based RRAM.

  12. Visible photon excited photoluminescence photometric characteristics of a green light emitting Zn2TiO4:Tb3+ nanophosphor for wLEDs

    NASA Astrophysics Data System (ADS)

    Girish, K. M.; Prashantha, S. C.; Naik, Ramachandra; Nagabhushana, H.; Nagaswarupa, H. P.; Premakumar, H. B.; Sharma, S. C.; Raju, K. S. Anantha

    2016-07-01

    A novel green light emitting Zn2TiO4:Tb3+ nanophosphor was synthesized via solution combustion synthesis and the final product was well characterized. From diffused reflectance spectra the energy band gap of the sample was estimated to be in the range 3.16–3.19 eV and the effect of Tb3+ on the electronic structure was calculated based on absolute electronegativity. The characteristic photoluminescence emission peak observed at 493 nm in the blue region was due to 5D3 → 7F3 and peaks at 515, 541, 579 and 620 nm corresponding to 5D4 → 7Fj (j = 6, 5, 4, 3), respectively, were due to f–f transitions of Tb3+ cations in the given host lattice upon 415 nm high energy visible photon excitation. Photometric characteristics suggest that the phosphors have a long lifetime, excellent color purity, color chromaticity coordinates and correlated color temperature values, so it is clearly evident that the optimized phosphor is quite useful for the green region of wLEDs, a ceramic pigment and for solid state display applications.

  13. On astrophysical solution to ultrahigh energy cosmic rays

    SciTech Connect

    Berezinsky, Veniamin; Gazizov, Askhat; Grigorieva, Svetlana

    2006-08-15

    We argue that an astrophysical solution to the ultrahigh energy cosmic ray (UHECR) problem is viable. The detailed study of UHECR energy spectra is performed. The spectral features of extragalactic protons interacting with the cosmic microwave background (CMB) are calculated in a model-independent way. Using the power-law generation spectrum {proportional_to}E{sup -{gamma}{sub g}} as the only assumption, we analyze four features of the proton spectrum: the GZK cutoff, dip, bump, and the second dip. We found the dip, induced by electron-positron production on the CMB, to be the most robust feature, existing in energy range 1x10{sup 18}-4x10{sup 19} eV. Its shape is stable relative to various phenomena included in calculations: discreteness of the source distribution, different modes of UHE proton propagation (from rectilinear to diffusive), local overdensity or deficit of the sources, large-scale inhomogeneities in the universe, and interaction fluctuations. The dip is well confirmed by observations of the AGASA, HiRes, Fly's Eye, and Yakutsk detectors. With two free parameters ({gamma}{sub g} and flux normalization constant) the dip describes about 20 energy bins with {chi}{sup 2}/d.o.f.{approx_equal}1 for each experiment. The best fit is reached at {gamma}{sub g}=2.7, with the allowed range 2.55-2.75. The dip is used for energy calibration of the detectors. For each detector independently, the energy is shifted by factor {lambda} to reach the minimum {chi}{sup 2}. We found {lambda}{sub Ag}=0.9, {lambda}{sub Hi}=1.2, and {lambda}{sub Ya}=0.75 for the AGASA, HiRes, and Yakutsk detectors, respectively. Remarkably, after this energy shift the fluxes and spectra of all three detectors agree perfectly, with discrepancy between AGASA and HiRes at E>1x10{sup 20} eV being not statistically significant. The excellent agreement of the dip with observations should be considered as confirmation of UHE proton interaction with the CMB. The dip has two flattenings. The high

  14. Statistical analysis of the correlation between active galactic nuclei and ultra-high energy cosmic rays

    SciTech Connect

    Kim, Hang Bae; Kim, Jihyun E-mail: jihyunkim@hanyang.ac.kr

    2011-03-01

    We develop the statistical methods for comparing two sets of arrival directions of cosmic rays in which the two-dimensional distribution of arrival directions is reduced to the one-dimensional distributions so that the standard one-dimensional Kolmogorov-Smirnov test can be applied. Then we apply them to the analysis of correlation between the ultra-high energy cosmic rays (UHECR) with energies above 5.7 × 10{sup 19} eV, observed by Pierre Auger Observatory (PAO) and Akeno Giant Air Shower Array (AGASA), and the active galactic nuclei (AGN) within the distance 100 Mpc. For statistical test, we set up the simple AGN model for UHECR sources in which a certain fraction of observed UHECR are originated from AGN within a chosen distance, assuming that all AGN have equal UHECR luminosity and smearing angle, and the remaining fraction are from the isotropic background contribution. For the PAO data, our methods exclude not only a hypothesis that the observed UHECR are simply isotropically distributed but also a hypothesis that they are completely originated from the selected AGN. But, the addition of appropriate amount of isotropic component either through the background contribution or through the large smearing effect improves the correlation greatly and makes the AGN hypothesis for UHECR sources a viable one. We also point out that restricting AGN within the distance bin of 40–60 Mpc happens to yield a good correlation without appreciable isotropic component and large smearing effect. For the AGASA data, we don't find any significant correlation with AGN.

  15. Charge transfer fluorescence and 34 nm exciton diffusion length in polymers with electron acceptor end traps

    DOE PAGESBeta

    Zaikowski, Lori; Mauro, Gina; Bird, Matthew; Karten, Brianne; Asaoka, Sadayuki; Wu, Qin; Cook, Andrew R.; Miller, John R.

    2014-12-22

    Photoexcitation of conjugated poly-2,7-(9,9-dihexylfluorene) polyfluorenes with naphthylimide (NI) and anthraquinone (AQ) electron-acceptor end traps produces excitons that form charge transfer states at the end traps. Intramolecular singlet exciton transport to end traps was examined by steady state fluorescence for polyfluorenes of 17 to 127 repeat units in chloroform, dimethylformamide (DMF), tetrahydrofuran (THF), and p-xylene. End traps capture excitons and form charge transfer (CT) states at all polymer lengths and in all solvents. The CT nature of the end-trapped states is confirmed by their fluorescence spectra, solvent and trap group dependence and DFT descriptions. Quantum yields of CT fluorescence are asmore » large as 46%. This strong CT emission is understood in terms of intensity borrowing. Energies of the CT states from onsets of the fluorescence spectra give the depths of the traps which vary with solvent polarity. For NI end traps the trap depths are 0.06 (p-xylene), 0.13 (THF) and 0.19 eV (CHCl3). For AQ, CT fluorescence could be observed only in p-xylene where the trap depth is 0.27 eV. Quantum yields, emission energies, charge transfer energies, solvent reorganization and vibrational energies were calculated. Fluorescence measurements on chains >100 repeat units indicate that end traps capture ~50% of the excitons, and that the exciton diffusion length LD =34 nm, which is much larger than diffusion lengths reported in polymer films or than previously known for diffusion along isolated chains. As a result, the efficiency of exciton capture depends on chain length, but not on trap depth, solvent polarity or which trap group is present.« less

  16. ULTRA-HIGH-ENERGY COSMIC RAYS FROM CENTAURUS A: JET INTERACTION WITH GASEOUS SHELLS

    SciTech Connect

    Gopal-Krishna; Biermann, Peter L.; De Souza, Vitor; Wiita, Paul J.

    2010-09-10

    Ultra-high-energy cosmic rays (UHECRs), with energies above {approx}6 x 10{sup 19} eV, seem to show a weak correlation with the distribution of matter relatively near to us in the universe. It has earlier been proposed that UHECRs could be accelerated in either the nucleus or the outer lobes of the nearby radio galaxy Cen A. We show that UHECR production at a spatially intermediate location about 15 kpc northeast from the nucleus, where the jet emerging from the nucleus is observed to strike a large star-forming shell of gas, is a plausible alternative. A relativistic jet is capable of accelerating lower energy heavy seed cosmic rays (CRs) to UHECRs on timescales comparable to the time it takes the jet to pierce the large gaseous cloud. In this model, many CRs arising from a starburst, with a composition enhanced in heavy elements near the knee region around PeV, are boosted to ultra-high energies by the relativistic shock of a newly oriented jet. This model matches the overall spectrum shown by the Auger data and also makes a prediction for the chemical composition as a function of particle energy. We thus predict an observable anisotropy in the composition at high energy in the sense that lighter nuclei should preferentially be seen toward the general direction of Cen A. Taking into consideration the magnetic field models for the Galactic disk and a Galactic magnetic wind, this scenario may resolve the discrepancy between HiRes and Auger results concerning the chemical composition of UHECRs.

  17. The Extreme Universe Space Observatory

    NASA Technical Reports Server (NTRS)

    Adams, Jim; Six, N. Frank (Technical Monitor)

    2002-01-01

    This talk will describe the Extreme Universe Space Observatory (EUSO) mission. EUSO is an ESA mission to explore the most powerful energy sources in the universe. The mission objectives of EUSO are to investigate EECRs, those with energies above 3x10(exp 19) eV, and very high-energy cosmic neutrinos. These objectives are directly related to extreme conditions in the physical world and possibly involve the early history of the big bang and the framework of GUTs. EUSO tackles the basic problem posed by the existence of these extreme-energy events. The solution could have a unique impact on fundamental physics, cosmology, and/or astrophysics. At these energies, magnetic deflection is thought to be so small that the EECR component would serve as the particle channel for astronomy. EUSO will make the first measurements of EAS from space by observing atmospheric fluorescence in the Earth's night sky. With measurements of the airshower track, EUSO will determine the energy and arrival direction of these extreme-energy events. EUSO will make high statistics observations of CRs beyond the predicted GZK cutoff energy and widen the channel for high-energy neutrino astronomy. The energy spectra, arrival directions, and shower profiles will be analyzed to distinguish the nature of these events and search for their sources. With EUSO data, we will have the possibility to discover a local EECR source, test Z-burst scenarios and other theories, and look for evidence of the breakdown of the relativity principle at extreme Lorentz factors.

  18. Rhabdomyolysis-Associated Mutations in Human LPIN1 Lead to Loss of Phosphatidic Acid Phosphohydrolase Activity.

    PubMed

    Schweitzer, George G; Collier, Sara L; Chen, Zhouji; Eaton, James M; Connolly, Anne M; Bucelli, Robert C; Pestronk, Alan; Harris, Thurl E; Finck, Brian N

    2015-01-01

    Rhabdomyolysis is an acute syndrome due to extensive injury of skeletal muscle. Recurrent rhabdomyolysis is often caused by inborn errors in intermediary metabolism, and recent work has suggested that mutations in the human gene encoding lipin 1 (LPIN1) may be a common cause of recurrent rhabdomyolysis in children. Lipin 1 dephosphorylates phosphatidic acid to form diacylglycerol (phosphatidic acid phosphohydrolase; PAP) and acts as a transcriptional regulatory protein to control metabolic gene expression. Herein, a 3-year-old boy with severe recurrent rhabdomyolysis was determined to be a compound heterozygote for a novel c.1904T>C (p.Leu635Pro) substitution and a previously reported genomic deletion of exons 18-19 (E766-S838_del) in LPIN1. Western blotting with patient muscle biopsy lysates demonstrated a marked reduction in lipin 1 protein, while immunohistochemical staining for lipin 1 showed abnormal subcellular localization. We cloned cDNAs to express recombinant lipin 1 proteins harboring pathogenic mutations and showed that the E766-S838_del allele was not expressed at the RNA or protein level. Lipin 1 p.Leu635Pro was expressed, but the protein was less stable, was aggregated in the cytosol, and was targeted for proteosomal degradation. Another pathogenic single amino acid substitution, lipin 1 p.Arg725His, was well expressed and retained its transcriptional regulatory function. However, both p.Leu635Pro and p.Arg725His proteins were found to be deficient in PAP activity. Kinetic analyses demonstrated a loss of catalysis rather than diminished substrate binding. These data suggest that loss of lipin 1-mediated PAP activity may be involved in the pathogenesis of rhabdomyolysis in lipin 1 deficiency. PMID:25967228

  19. Natriuretic peptide receptors in the fetal rat.

    PubMed

    Brown, J; Zuo, Z

    1995-08-01

    In vitro autoradiography of rat fetuses from embryonic days 12-19 (E12-E19) showed widespread high-affinity specific binding sites for natriuretic peptides. The sites on E16 somites avidly bound C-type natriuretic peptide [CNP-(1-22)] as well as C-ANP, a synthetic ligand that selects the C-type natriuretic peptide receptor (NPR-C). Most somitic binding sites had high affinity for atrial natriuretic peptide [ANP-(1-28)], confirming their resemblance to NPR-C. A few had a lower apparent affinity for ANP-(1-28), suggesting that they might be NPR-B. CNP-(1-22) was more powerful than ANP-(1-28) as an agonist of guanosine 3',5'-cyclic monophosphate production in somites, and ATP augmented the action of CNP-(1-22). These observations further suggest the presence of NPR-B. However, with cross-linking of 3-[125I]iodo-0-tyrosyl rat CNP-(1-22) to somitic membranes followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, only a single 64-kDa binding protein was detected under reducing conditions. This is not consistent with intact approximately 120-kDa NPR-B. In vitro autoradiography of the binding of natriuretic peptides to E16 liver implied the presence of NPR-A and NPR-C-like receptors. Hepatic guanosine 3',5'-cyclic monophosphate production was most powerfully stimulated by ANP-(1-28), as expected for NPR-A. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis also identified NPR-A and NPR-C-like proteins in E16 hepatic membranes. Thus different NPRs are expressed by specific fetal tissues. This may be developmentally significant. PMID:7653543

  20. Electronic Structure and Optical Properties of Cu2ZnGeSe4 : First-Principles Calculations and Vacuum-Ultraviolet Spectroscopic Ellipsometric Studies

    NASA Astrophysics Data System (ADS)

    Choi, S. G.; Park, J.-S.; Donohue, A. L.; Christensen, S. T.; To, B.; Beall, C.; Wei, S.-H.; Repins, I. L.

    2015-11-01

    Cu2ZnGeSe4 is of interest for the development of next-generation thin-film photovoltaic technologies. To understand its electronic structure and related fundamental optical properties, we perform first-principles calculations for three structural variations: kesterite, stannite, and primitive-mixed CuAu phases. The calculated data are compared with the room-temperature dielectric function ɛ =ɛ1+i ɛ2 spectrum of polycrystalline Cu2ZnGeSe4 determined by vacuum-ultraviolet spectroscopic ellipsometry in the photon-energy range of 0.7 to 9.0 eV. Ellipsometric data are modeled with the sum of eight Tauc-Lorentz oscillators, and the best-fit model yields the band-gap and Tauc-gap energies of 1.25 and 1.19 eV, respectively. A comparison of overall peak shapes and relative intensities between experimental spectra and the calculated ɛ data for three structural variations suggests that the sample may not have a pure (ordered) kesterite phase. The complex refractive index N =n +i k , normal-incidence reflectivity R , and absorption coefficients α are calculated from the modeled ɛ spectrum, which are also compared with those of Cu2ZnSnSe4 . The spectral features for Cu2ZnGeSe4 appear to be weaker and broader than those for Cu2ZnSnSe4 , which is possibly due to more structural imperfections presented in Cu2ZnGeSe4 than Cu2ZnSnSe4 .

  1. SNP-SNP interaction analysis of NF-κB signaling pathway on breast cancer survival.

    PubMed

    Jamshidi, Maral; Fagerholm, Rainer; Khan, Sofia; Aittomäki, Kristiina; Czene, Kamila; Darabi, Hatef; Li, Jingmei; Andrulis, Irene L; Chang-Claude, Jenny; Devilee, Peter; Fasching, Peter A; Michailidou, Kyriaki; Bolla, Manjeet K; Dennis, Joe; Wang, Qin; Guo, Qi; Rhenius, Valerie; Cornelissen, Sten; Rudolph, Anja; Knight, Julia A; Loehberg, Christian R; Burwinkel, Barbara; Marme, Frederik; Hopper, John L; Southey, Melissa C; Bojesen, Stig E; Flyger, Henrik; Brenner, Hermann; Holleczek, Bernd; Margolin, Sara; Mannermaa, Arto; Kosma, Veli-Matti; Van Dyck, Laurien; Nevelsteen, Ines; Couch, Fergus J; Olson, Janet E; Giles, Graham G; McLean, Catriona; Haiman, Christopher A; Henderson, Brian E; Winqvist, Robert; Pylkäs, Katri; Tollenaar, Rob A E M; García-Closas, Montserrat; Figueroa, Jonine; Hooning, Maartje J; Martens, John W M; Cox, Angela; Cross, Simon S; Simard, Jacques; Dunning, Alison M; Easton, Douglas F; Pharoah, Paul D P; Hall, Per; Blomqvist, Carl; Schmidt, Marjanka K; Nevanlinna, Heli

    2015-11-10

    In breast cancer, constitutive activation of NF-κB has been reported, however, the impact of genetic variation of the pathway on patient prognosis has been little studied. Furthermore, a combination of genetic variants, rather than single polymorphisms, may affect disease prognosis. Here, in an extensive dataset (n = 30,431) from the Breast Cancer Association Consortium, we investigated the association of 917 SNPs in 75 genes in the NF-κB pathway with breast cancer prognosis. We explored SNP-SNP interactions on survival using the likelihood-ratio test comparing multivariate Cox' regression models of SNP pairs without and with an interaction term. We found two interacting pairs associating with prognosis: patients simultaneously homozygous for the rare alleles of rs5996080 and rs7973914 had worse survival (HRinteraction 6.98, 95% CI=3.3-14.4, P=1.42E-07), and patients carrying at least one rare allele for rs17243893 and rs57890595 had better survival (HRinteraction 0.51, 95% CI=0.3-0.6, P = 2.19E-05). Based on in silico functional analyses and literature, we speculate that the rs5996080 and rs7973914 loci may affect the BAFFR and TNFR1/TNFR3 receptors and breast cancer survival, possibly by disturbing both the canonical and non-canonical NF-κB pathways or their dynamics, whereas, rs17243893-rs57890595 interaction on survival may be mediated through TRAF2-TRAIL-R4 interplay. These results warrant further validation and functional analyses. PMID:26317411

  2. Characterization of molybdenum doped indium oxide/aluminum doped zinc oxide thin film stacks for optoelectronic applications

    NASA Astrophysics Data System (ADS)

    Elamurugu, Elangovan; Flores, Raquel; Janeiro, Ricardo; Dahlem, Marcus; Viegas, Jaime

    2014-03-01

    Multilayer (ML) thin films, based on indium molybdenum oxide (IMO) and aluminum zinc oxide (AZO), having different stacking were deposited using RF sputtering at room temperature (RT). The total-layer thickness of the MLs ranges between 93 nm and 98 nm. The deposited films were characterized by their structural, electrical, microstructural, and optical properties. X-ray diffraction (XRD) peaks obtained at 2θ of around 30.6° and 34.27° are matched with cubic-In2O3 (222) and hexagonal-ZnO (002), respectively. The MLs have both nano-crystalline and polycrystalline structures depending on the layer properties. A conspicuous feature of XRD analysis is the absence of diffraction peak from 50 nm thick IMO layer when it is stacked below 50 nm thick AZO, whereas it appears significantly when the stacking is reversed to place IMO above AZO layer. Hall measurements confirmed that the deposited MLs are n- type conducting and the electrical properties are varied as a function of layer properties. The deposited MLs show high shortwavelength infrared transmittance (SWIRT) even at 3300 nm, which is ranging as high as 75 % - 90 %. Overall, the MLs show high transmittance in the entire Vis-SWIR region. The optical band gap (Eg) calculated using the absorption coefficient (α) and photon energy (hν) of the deposited MLs is ranging between 3.19 eV and 3.56 eV, depending on the layer properties. Selected as- deposited films were annealed in open air at 400 °C for 1 h; the transmittance of annealed films was improved but their electrical properties deteriorated. Atomic force microscopy (AFM) analysis shows that the root-mean-square (RMS) roughness of the MLs ranges between 0.8 nm and 1.5 nm.

  3. Effects of Annealing on Electrical Characteristics and Current Transport Mechanisms of the Y/ p-GaN Schottky Diode

    NASA Astrophysics Data System (ADS)

    Reddy, V. Rajagopal; Asha, B.; Choi, Chel-Jong

    2016-07-01

    This study investigates the effects of annealing on the electrical properties and current transport mechanism of Y/ p-GaN Schottky barrier diodes (SBDs). We found no significant change in the surface morphology of the Y Schottky contacts during the annealing process. The Schottky barrier height (SBH) of the as-deposited Y/ p-GaN SBD was estimated to be 0.95 eV ( I- V)/1.19 eV ( C- V). The SBH increased upon annealing at 400°C and 500°C, and then decreased slightly with annealing at 600°C. Thus the maximum SBH of the Y/ p-GaN SBD was achieved at 500°C, with values of 1.01 eV ( I- V)/1.29 eV ( C- V). In addition, the SBH values were estimated by Cheung's, Norde, and Ψs- V plots and were found to be in good agreement with one another. Series resistance ( R S) values were also calculated by I- V, Cheung's, and Norde functions at different annealing temperatures, with results showing a decrease in the interface state density of the SBD with annealing at 500°C, followed by a slight increase upon annealing at 600°C. The forward-bias current transport mechanism of SBD was investigated by the log I-log V plot at different annealing temperatures. Our investigations revealed that the Poole-Frenkel emission mechanism dominated the reverse leakage current in Y/ p-GaN SBD at all annealing temperatures.

  4. Dobutamine stress--Doppler echocardiography before and after coronary angioplasty.

    PubMed

    el-Said, E S; Fioretti, P M; Roelandt, J R; McNeill, A J; Rijsterborgh, H; Forster, T; Di Mario, C; Linker, D T

    1993-08-01

    To determine if dobutamine-induced myocardial ischaemia causes abnormalities in Doppler parameters of left ventricular ejection and filling and to assess early effects of successful coronary angioplasty (PTCA) on these parameters, dobutamine stress echocardiography and Doppler studies were performed once in 11 normal volunteers and twice in 17 patients (within 1 day pre- and post-PTCA). Dobutamine induced wall motion abnormalities, ST changes and angina in 11, five and five patients, respectively, before and three, two and one patients, respectively, after PTCA. Doppler indices of both systolic and diastolic function were comparable at rest, before and after PTCA. Dobutamine induced similar increases in peak aortic velocity and average acceleration in healthy individuals (39% and 53%) and in patients with one-vessel disease both before (38% and 39%) and after PTCA (39% and 40%). In the three patients with multivessel disease, peak aortic velocity showed a blunted response (-0.3%) before PTCA but increased by 17% after PTCA, while acceleration decreased both before (12%) and after PTCA (14%). There were significant differences (P < 0.0001) between healthy individuals and pre-PTCA patients in the effect of dobutamine on peak early (E) filling velocity (+34% vs -19%), E-acceleration (+35% vs -26%), peak early to atrial filling velocity ratio (E/A) (-0.7% vs -37%) and diastolic time velocity integral (TVI) (+34% vs -22%). After PTCA, the response of Doppler diastolic indices improved during dobutamine, as shown by the increase in E and E-acceleration (+8%, +24%), respectively) and by the decline in the reduction of E/A and TVI (-17% and -10%, respectively). Thus, the response of Doppler diastolic parameters to dobutamine stress is a sensitive indicator of significant coronary disease and is superior to changes in ejection indices. Successful PTCA resulted in an improved diastolic filling response to dobutamine stress. PMID:8404930

  5. Study of low-lying electronic states of ozone by multireference Møller-Plesset perturbation method

    NASA Astrophysics Data System (ADS)

    Tsuneda, T.; Nakano, H.; Hirao, K.

    1995-10-01

    The geometry and relative energy of the seven low-lying electronic states of ozone and the ground state of ozonide anion have been determined in C2v symmetry by the complete active space self-consistent field (CASSCF) and the multireference Møller-Plesset perturbation (MRMP) methods. The results are compared with the photodetachment spectra of O-3 observed recently by Arnold et al. The theoretical electron affinity of ozone is 1.965 eV, which is 0.14 eV below the experimental result of 2.103 eV. The calculated adiabatic excitation energies (assignment of Arnold et al. in parentheses) of ozone are 3A2 0.90 eV (1.18 eV), 3B2, 1.19 eV (1.30 eV), 3B1, 1.18 eV (1.45 eV), 1A2, 1.15 eV (˜1.6 eV), 1B1, 1.65 eV (2.05 eV), and 1B2, 3.77 eV (3.41 eV), respectively. Overall the present theory supports the assignment of Arnold et al. However, the simple considerations of geometry and energy are insufficient to determine a specific assignment of the 3B2 and 3B1 states. The dissociation energy of the ground state of ozone is computed to be 0.834 eV at the present level of theory. The present theory also predicts that none of the excited states lies below the ground state dissociation limit of O3.

  6. The NDR Kinase Cbk1 Downregulates the Transcriptional Repressor Nrg1 through the mRNA-Binding Protein Ssd1 in Candida albicans

    PubMed Central

    Lee, Hye-Jeong; Kim, Jong-Myeong; Kang, Woo Kyu; Yang, Heebum

    2015-01-01

    NDR (nuclear Dbf2-related) kinases are essential components for polarized morphogenesis, cytokinesis, cell proliferation, and apoptosis. The NDR kinase Cbk1 is required for the hyphal growth of Candida albicans; however, the molecular functions of Cbk1 in hyphal morphogenesis are largely unknown. Here, we report that Cbk1 downregulates the transcriptional repressor Nrg1 through the mRNA-binding protein Ssd1, which has nine Cbk1 phosphorylation consensus motifs. We found that deletion of SSD1 partially suppressed the defective hyphal growth of the C. albicans cbk1Δ/Δ mutant and that Ssd1 physically interacts with Cbk1. Cbk1 was required for Ssd1 localization to polarized growth sites. The phosphomimetic SSD1 allele (ssd1-9E) allowed the cbk1Δ/Δ mutant to form short hyphae, and the phosphodeficient SSD1 allele (ssd1-9A) resulted in shorter hyphae than did the wild-type SSD1 allele, indicating that Ssd1 phosphorylation by Cbk1 is important for hyphal morphogenesis. Furthermore, we show that the transcriptional repressor Nrg1 does not disappear during hyphal initiation in the cbk1Δ/Δ mutant but is completely absent in the cbk1Δ/Δ ssd1Δ/Δ double mutant. Deletion of SSD1 also increased Als3 expression and internalization of the cbk1Δ/Δ mutant in the human embryonic kidney cell line HEK293T. Collectively, our results suggest that one of the functions of Cbk1 in the hyphal morphogenesis of C. albicans is to downregulate Nrg1 through Ssd1. PMID:26002720

  7. First results on neutrinoless double beta decay of 130Te with the calorimetric CUORICINO experiment

    NASA Astrophysics Data System (ADS)

    Arnaboldi, C.; Artusa, D. R.; Avignone, F. T.; Balata, M.; Bandac, I.; Barucci, M.; Beeman, J. W.; Brofferio, C.; Bucci, C.; Capelli, S.; Capozzi, F.; Carbone, L.; Cebrian, S.; Cremonesi, O.; Creswick, R. J.; de Waard, A.; Farach, H. A.; Fascilla, A.; Fiorini, E.; Frossati, G.; Giuliani, A.; Gorla, P.; Haller, E. E.; McDonald, R. J.; Morales, A.; Norman, E. B.; Nucciotti, A.; Olivieri, E.; Palmieri, E.; Pasca, E.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Pobes, C.; Previtali, E.; Pyle, M.; Risegari, L.; Rosenfeld, C.; Sangiorgio, S.; Sisti, M.; Smith, A. R.; Torres, L.; Ventura, G.

    2004-04-01

    The first results are reported on the limit for neutrinoless double decay of 130Te obtained with the new bolometric experiment CUORICINO. The set-up consists of 44 cubic crystals of natural TeO2, 5 cm on the side and 18 crystals of 3×3×6 cm3. Four of these latter crystals are made with isotopically enriched materials: two in 128Te and two others in 130Te. With a sensitive mass of ∼40 kg, our array is by far the most massive running cryogenic detector to search for rare events. The array is operated at a temperature of ∼10 mK in a dilution refrigerator under a heavy shield in the Gran Sasso Underground Laboratory at a depth of about 3500 m.w.e. The counting rate in the region of neutrinoless double beta decay is ∼0.2 counts keV-1 kg-1 y-1, among the lowest in this type of experiment. No evidence for neutrinoless double beta decay is found with the present statistics obtained in about three months with a live time of 72%. The corresponding lower limit for the lifetime of this process is of 5.5×1023 years at 90% C.L. The corresponding limit for the effective neutrino mass ranges between 0.37 to 1.9 eV depending on the theoretically calculated nuclear matrix elements used. This constraint is the most restrictive one except those obtained with Ge diodes, and is comparable to them.

  8. Ab initio molecular orbital calculations of DNA radical ions. 5. Scaling of calculated electron affinities and ionization potentials to experimental values

    SciTech Connect

    Sevilla, M.D.; Colson, A.O. ); Besler, B. )

    1995-01-19

    Ab initio molecular orbital calculations of the electron affinities (EAs) and ionization potentials (IPs) of the DNA bases are presented in this work. Comparisons of calculated and experimental values are made for a series of compounds of size and/or structure similar to the DNA bases. Excellent correlations between calculated and experimental values are found for both Koopmans EAs at the 6-31G[sup *] and D95v levels and calculated vertical EAs of the model compounds. Several basis sets are considered: 6-31G[sup *], 6-31+G(d), and D95v. Calculations at 6-31G[sup *] and 6-31+G(d) using both ROHF and ROMP2 theories show a consistent difference between calculated vertical and adiabatic EAs. This allows for a good estimate of DNA base adiabatic EAs. i.e., -0.7, -0.3, 0.2, 0.3, and 0.4 eV; from the vertical EAs -1.23, -0.74, -0.40, -0.32, and -0.19 eV for G, A, C, T, and U respectively. While EAs must be scaled, we find that Koopmans IPs calculated at the simple 3-21G level predict vertical IPs of the DNA bases with only a 0.15 eV average absolute deviation from the experimentally reported values and calculations at MP2/6-31+G(d)//6-31G[sup *] for the adiabatic ionization potentials of the DNA bases are all within 0.1 eV of experiment. 41 refs., 2 figs., 5 tabs.

  9. Charge transfer fluorescence and 34 nm exciton diffusion length in polymers with electron acceptor end traps

    SciTech Connect

    Zaikowski, Lori; Mauro, Gina; Bird, Matthew; Karten, Brianne; Asaoka, Sadayuki; Wu, Qin; Cook, Andrew R.; Miller, John R.

    2014-12-22

    Photoexcitation of conjugated poly-2,7-(9,9-dihexylfluorene) polyfluorenes with naphthylimide (NI) and anthraquinone (AQ) electron-acceptor end traps produces excitons that form charge transfer states at the end traps. Intramolecular singlet exciton transport to end traps was examined by steady state fluorescence for polyfluorenes of 17 to 127 repeat units in chloroform, dimethylformamide (DMF), tetrahydrofuran (THF), and p-xylene. End traps capture excitons and form charge transfer (CT) states at all polymer lengths and in all solvents. The CT nature of the end-trapped states is confirmed by their fluorescence spectra, solvent and trap group dependence and DFT descriptions. Quantum yields of CT fluorescence are as large as 46%. This strong CT emission is understood in terms of intensity borrowing. Energies of the CT states from onsets of the fluorescence spectra give the depths of the traps which vary with solvent polarity. For NI end traps the trap depths are 0.06 (p-xylene), 0.13 (THF) and 0.19 eV (CHCl3). For AQ, CT fluorescence could be observed only in p-xylene where the trap depth is 0.27 eV. Quantum yields, emission energies, charge transfer energies, solvent reorganization and vibrational energies were calculated. Fluorescence measurements on chains >100 repeat units indicate that end traps capture ~50% of the excitons, and that the exciton diffusion length LD =34 nm, which is much larger than diffusion lengths reported in polymer films or than previously known for diffusion along isolated chains. As a result, the efficiency of exciton capture depends on chain length, but not on trap depth, solvent polarity or which trap group is present.

  10. Structural and Magnetic Properties of Dilute Ca²⁺ Doped Iron Oxide Nanoparticles.

    PubMed

    Samar Layek; Rout, K; Mohapatra, M; Anand, S; Verma, H C

    2016-01-01

    Undoped and calcium substituted hematite (α-Fe₂O₃) nanoparticles are synthesized by surfactant-directed co-precipitation and post annealing method. The annealed nanoparticles were found to be in single phase in nature and crystallize in the rhombohedral structure with space group R3c as confirmed by Rietveld refinement of the X-ray diffraction (XRD) data. Average crystallite sizes are calculated to be 20 to 30 nm and 50 to 60 nm for the nanoparticles annealed at 400 and 600 °C respectively. Mössbauer spectra for all the nanoparticles could be fitted with a sextet corresponding to the single magnetic state of the iron atoms in its Fe³⁺ state in the hematite matrix. The FTIR and Raman spectra of all the samples correspond to specific modes of α-Fe₂O₃. UV-Vis spectra of annealed samples showed broad peaks in the range of 525-630 nm resulting from spin-forbidden ligand field transition together with the spin-flip transition among the 2t₂g states. The estimated band gap energies were in the range of 1.6 to 1.9 eV which are much lower than the reported values for nano hematite. From the room temperature magnetic hysteresis loop measurements, weak ferromagnetic behavior is observed in all undoped and Ca²⁺ doped hematite samples. Morin temperature (T(M)) is calculated to be 257 and 237 K for 1.45% doped samples with particle size 54 and 27 nm respectively. The sample with Ca content of 1.45 wt% when annealed at 400 °C showed that the particles were of different shapes which included both quasi spherical and rod shaped. On annealing the same sample at 600 °C, the nanorods collapsed to form bigger spherical and ellipsoidal particles. PMID:27398469

  11. Cytotoxic Compounds from the Saudi Red Sea Sponge Xestospongia testudinaria.

    PubMed

    El-Gamal, Ali A; Al-Massarani, Shaza M; Shaala, Lamiaa A; Alahdald, Abdulrahman M; Al-Said, Mansour S; Ashour, Abdelkader E; Kumar, Ashok; Abdel-Kader, Maged S; Abdel-Mageed, Wael M; Youssef, Diaa T A

    2016-01-01

    Bioassay-guided fractionation of the organic extract of the Red Sea sponge Xestospongia testudinaria led to the isolation of 13 compounds including two new sterol esters, xestosterol palmitate (2) and xestosterol ester of l6'-bromo-(7'E,11'E,l5'E)-hexadeca-7',11',l5'-triene-5',13'-diynoic acid (4), together with eleven known compounds: xestosterol (1), xestosterol ester of 18'-bromooctadeca-7'E,9'E-diene-7',15'-diynoic acid (3), and the brominated acetylenic fatty acid derivatives, (5E,11E,15E,19E)-20-bromoeicosa-5,11,15,19-tetraene-9,17-diynoic acid (5), 18,18-dibromo-(9E)-octadeca-9,17-diene-5,7-diynoic acid (6), 18-bromooctadeca-(9E,17E)-diene-7,15-diynoic acid (7), 18-bromooctadeca-(9E,13E,17E)-triene-7,15-diynoic acid (8), l6-bromo (7E,11E,l5E)hexadeca-7,11,l5-triene-5,13-diynoic acid (9), 2-methylmaleimide-5-oxime (10), maleimide-5-oxime (11), tetillapyrone (12), and nortetillapyrone (13). The chemical structures of the isolated compounds were accomplished using one- and two-dimensional NMR, infrared and high-resolution electron impact mass spectroscopy (1D, 2D NMR, IR and HREIMS), and by comparison with the data of the known compounds. The total alcoholic and n-hexane extracts showed remarkable cytotoxic activity against human cervical cancer (HeLa), human hepatocellular carcinoma (HepG-2), and human medulloblastoma (Daoy) cancer cell lines. Interestingly, the dibrominated C18-acetylenic fatty acid (6) exhibited the most potent growth inhibitory activity against these cancer cell lines followed by Compounds 7 and 9. Apparently, the dibromination of the terminal olefinic moiety has an enhanced effect on the cytotoxic activity. PMID:27128926

  12. The Saturn system viewed through the infrared eyes of Cassini CIRS

    NASA Astrophysics Data System (ADS)

    Flasar, F. M.

    2014-04-01

    CIRS thermal-infrared spectra have been used to retrieve temperatures and atmospheric composition within the Saturn system. We review several major findings, including: Saturn. a) The outburst of a major storm at northern latitudes, resulting in an enhancement of tropospheric phosphine [1] and a depletion of para-hydrogen [2], and a perturbed stratosphere, characterized by anticyclonic structure with high-temperatures, associated with largeamplitude vertical motions [3], and enhanced ethylene [4]. The perturbed structure of the stratosphere is long-lived, persisting after the visible tropospheric disturbance has decayed. b) The structure and descending pattern of a stratospheric oscillation at the equator [5], [6]. c) Evidence for descent over both winter and summer poles, leading to warm temperatures and depleted phosphine [7]. Titan. a) The structure and seasonal behavior of the circumpolar vortices, as seen in temperatures, zonal winds, trace gas distribution, and condensates [8], [9]. [10], [11], [12], [13], [14]. b) The polar offset of cyclostrophic flow in the stratosphere [15], [16]. c) The spatial variation of stratospheric methane [17]. d) The meridional and seasonal variation of surface temperatures [18], [19]. e) The first detection of propylene [20]. Rings. a) The existence of a population of ring particles in the main rings that are relatively large, spin slowly, and have a low enough thermal inertia to provide a thermal response that is rapid compared to the particle rotation period [21]. b) The determination of minimum ring temperatures, seen at equinox [22]. c) The temperature modulations in the A ring caused by self-gravity wakes [23], [24]. Icy Satellites. a) The discovery of warm temperatures and endogenic thermal emission in the major fissures around Enceladus's south pole [25], [26]. b) The identification of the pac-man features on Mimas and Tethys, indicative of variations in thermal inertia that are likely caused by electron bombardment over

  13. Studies of pure and nitrogen-incorporated hydrogenated amorphous carbon thin films and their possible application for amorphous silicon solar cells

    SciTech Connect

    Dwivedi, Neeraj; Kumar, Sushil; Malik, Hitendra K.

    2012-01-01

    Hydrogenated amorphous carbon (a-C:H) and nitrogen-incorporated a-C:H (a-C:N:H) thin films were deposited using radio frequency-plasma-enhanced chemical vapor deposition technique and studied for their electrical, optical, and nano-mechanical properties. Introduction of nitrogen and increase of self bias enhanced the conductivity of a-C:H and a-C:N:H films, whereas current-voltage measurement reveals heterojunction formation due to their rectifying behavior. The bandgap of these films was changed over wide range from 1.9 eV to 3.45 eV by varying self bias and the nitrogen incorporation. Further, activation energy was correlated with the electronic structure of a-C:H and a-C:N:H films, and conductivity was discussed as a function of bandgap. Moreover, a-C:N:H films exhibited high hardness and elastic modulus, with maximum values as 42 GPa and 430 GPa, respectively, at -100 V. Observed fascinating electrical, optical, and nano-mechanical properties made it a material of great utility in the development of optoelectronic devices, such as solar cells. In addition, we also performed simulation study for an a-Si:H solar cell, considering a-C:H and C:N:H as window layers, and compared their performance with the a-Si:H solar cell having a-SiC:H as window layer. We also proposed several structures for the development of a near full-spectrum solar cell. Moreover, due to high hardness, a-C:N:H films can be used as a protective and encapsulate layer on solar cells, especially in n-i-p configuration on metal substrate. Nevertheless, a-C:H and a-C:N:H as a window layer can avoid the use of additional hard and protective coating and, hence, minimize the cost of the product.

  14. The Effect of Mn Incorporation on the Structural, Morphological, Optical, and Electrical Features of Nanocrystalline ZnO Thin Films Prepared by Chemical Spray Pyrolysis Technique

    NASA Astrophysics Data System (ADS)

    Yilmaz, Mehmet; Aydoğan, Şakir

    2015-06-01

    Un-doped and Mn-doped ZnO nanocrystalline thin films and n-ZnO /n-Si heterojunction have been prepared by chemical spray pyrolysis technique. The microstructure, morphology, optical, and electrical properties have been studied. The X-ray analyses have revealed that all films are in single phase and have wurtzite structure. Besides, it has been indicated that there are not any secondary phases. The optical properties have been evaluated by UV-Vis measurement. It has shown that band gap decreases with Mn incorporation from 3.29 to 3.19 eV. Schottky diode applications of the films have been performed by evaporation of Au on pure and Mn-doped ZnO films. Current-voltage (I-V) and capacitance-voltage (C-V) measurements of the n-ZnO /n-Si heterojunction indicate good diode characteristic and the barrier heights have been calculated as 0.89 and 0.79 eV for un-doped and Mn 1 pct-doped ZnO films. Besides, schematic cross section of the Au/ n-ZnO/ n-Si/Al device and energy band diagram of n-ZnO/ n-Si heterojunction has been illustrated to clarify the transport mechanism. All results suggest that the characteristic properties of the ZnO thin films can be adjustable with the Mn doping and Al/ n-Si/ n-ZnO/Au diode can be used for UV detection application in photonic devices.

  15. 700 keV Ni+2 ions induced modification in structural, surface, magneto-optic and optical properties of ZnO thin films

    NASA Astrophysics Data System (ADS)

    Fiaz Khan, M.; Siraj, K.; Anwar, M. S.; Irshad, M.; Hussain, J.; Faiz, H.; Majeed, S.; Dosmailov, M.; Patek, J.; Pedarnig, J. D.; Rafique, M. S.; Naseem, S.

    2016-02-01

    We investigate the effect of 700 keV Ni+2 ions irradiation at different ion fluences (1 × 1013, 1 × 1014, 2 × 1014, 5 × 1014 ions/cm2) on the structural, surface, magneto-optic and optical properties of ZnO thin films. The X-ray diffraction (XRD) results show improved crystallinity when ion fluence is increased to 2 × 1014 ions/cm2, while deterioration is observed at the highest ion fluence of 5 × 1014 ions/cm2. Scanning electron micrographs (SEM) show the formation of small grains at ion fluence 1 × 1013 ions/cm2, micro-rods at fluences 1 × 1014 and 2 × 1014 ions/cm2 and ultimate fracturing of thin film surface at ion fluence 5 × 1014 ions/cm2. Faraday rotation measurements are also performed and show a decrease in Verdet constant from 53 to 31 rad/(T-m) when irradiated at 1 × 1013 ions/cm2, increasing up to 45 rad/(T-m) at 2 × 1014 ions/cm2, and then decreasing again to 36 rad/(T-m) at 5 × 1014 ions/cm2. The optical band gap energy of the films is determined using spectroscopic ellipsometry, which shows an increase in optical band gap energy (Eg) from 3.04 eV to 3.19 eV when the fluence increases to 2 × 1014 ions/cm2 and a decrease to 3 eV at fluence 5 × 1014 ions/cm2. We argue that these properties can be explained using ion heating effect of thin films.

  16. Correlation between electrical properties and thermodynamic stability of ACoO{sub 3-{delta}} perovskites (A= La, Pr, Nd, Sm, Gd)

    SciTech Connect

    Scherrer, Barbara; Harvey, Ashley S.; Martynczuk, Julia; Gauckler, Ludwig J.; Tanasescu, Speranta; Teodorescu, Florina; Botea, Alina; Conder, Kazimierz; Grundy, A. Nicholas

    2011-08-15

    For perovskites with the general formula ACoO{sub 3-{delta}} (A = La, Pr, Nd, Sm, and Gd) the influence of the A-site cation on the electrical conductivity, electronic structure, thermodynamic stability, and oxygen stoichiometry was studied. The perovskite oxide powders were produced by a combined citric acid and ethylenediaminetetraacetic acid complexing method. Ceramic specimens sintered at 1100 deg. C in air were single-phase perovskites. With increasing temperature, the electrical conductivity shows three discrete regimes. All compositions show semiconductivity up to a transition temperature of {approx}300 deg. C-450 deg. C and then behave like metallic conductors. The activation energies for the semiconductivity, as well as the transition temperatures to the metallic-like conduction, decrease monotonically with increasing pseudocubic lattice parameters, i.e., with increasing ionic radii of the A cation. This behavior correlates with decreasing oxygen nonstoichiometry and increased thermodynamic stability. The highest conductivity and the lowest activation energy of 0.66 eV were found for LaCoO{sub 3-{delta},} which also had the lowest semiconductor-metal transition temperature at 269 deg. C, the lowest oxygen nonstoichiometry of {delta}= 0.008, and the highest Gibbs free energy change for the decomposition reaction of 42.37 kJ/mol at 850 deg. C. GdCoO{sub 3-{delta}} had the highest oxygen nonstoichiometry with {delta}0.032, a high activation energy of 1.19 eV for the semiconductivity with a high transition temperature at 452 deg. C, and the lowest Gibbs free energy change of 26.54 kJ/mol at 850 deg. C. X-ray absorption spectroscopy data imply an increasing Co low-spin character with decreasing cation radius from La to Gd, while an increase in temperature increases the number of holes or Co 3d bandwidth. This correlates well with the electrical conductivity data.

  17. [THE DESCRIPTION OF MYXOBOLUS PELECICOLA SP. NOV. (MYXOZOA: MYXOBOLIDAE) FROM PELECUS CULTRATUS (CYPRINIFORMES, CYPRINIDAE)].

    PubMed

    Voronin, V N; Dudin, A S

    2015-01-01

    Morphological study of myxosporean parasites Myxobolus pelecicola sp. n. from Pele- cus cultratus (L., 1758), is presented. Presporogenic stage not observed. Polysporous, el- lipsoidal. plasmodia up to 1.2 mm in length and 0.1 to 0.4 mm in width develop in the ske- letal musculature. Mature spores elongate oval or oval form in frontal view, lens-shaped in sutural view. Length of spores 16.5 ± 0.83 (14.9-18.0), width 12.1 ± 0.63 (11.6-13.3) (n = 50), thickness 7.8 ± 0.3 (7.4-8.3) µm (n = 10). Polar capsules pyriform, unequal, length of large 8.0 ± 0.44 (7.5-8.8), small 7.6 ± 0.26 (7.2-7.8), width of large 4.5 ± 0.22 (4.2-4.7), small 4.0 ± 0.21 (3.8-4.3) µm. Five to 6 distinct filament coils oriented obli- quely to capsule length, found in polar capsule. The length of extruded (in water) filament up to 130 µm. Large, but indistinct triangular intercapsular appendix present in spores. Single rodlet inclusion is very often observed in the posterior part of spore. Mucous enve- lope is absent. The type host of Myxobolus pelecicola sp. n. is sabrefish Pelecus cultratus (L., 1758). Type locality: Finnish Bay (60°05' N 29°55' E) and Ladoga lake (60°07' N 32°19' E), Russia. PMID:26827485

  18. "Urban heat island" effect on tree growth at several cities of Northern Europe

    NASA Astrophysics Data System (ADS)

    Shumilov, O. I.; Kasatkina, E. A.; Timonen, M.; Herva, H.; Kirtsideli, I.; Kanatjev, A. G.

    2010-05-01

    We investigated growth of larches being planted at several cities of Northern Europe: St. Petersburg (59°57'N, 30°19'E), Rovaniemi (66°30'N, 25°44'E), Apatity (67°34'N, 33°23'E). The data were collected at several sites inside of each city, and at one site in the rural area outside of each cities (about 50 km apart). Totally we studied 10 series. The longest chronology was about 190 years (in St. Petersburg). However, the most others were not very long (about 50 - 70 years). Firstly, it was shown that tree-rings of planted (not typical) larch trees don't reflect the influence of external (solar) factors in contrast with natural species. That is it could not be possible to detect some warming for the 1930-1960 period and some cooling later on. This effect was observed for both series inside the cities and outside of them. Secondly, it was revealed that for both northern cities (Apatity and Rovaniemi) variability of tree-ring indexes was more pronounced in series collected inside of them. Another situation was found for St. Petersburg. Growth of larch trees was stable inside of this megapolis. The preliminary interpretation of the results obtained seems to be connected to different influence of "urban heat island" effect on planted trees inside and outside of the cities for megapolis and relatively small towns. This work is financially supported by the Russian Foundation for Basic Research (grant No. 09-04-98801), by the Program of the Russian Academy and by the Regional Scientific Program of Murmansk region.

  19. Recently Determined Light Elements for the delta Scuti Star ZZ Microscopii

    NASA Astrophysics Data System (ADS)

    Axelsen, R. A.; Napier-Munn, T.

    2015-06-01

    The delta Scuti star ZZ Microscopii (HD 199757) was studied by photoelectric photometry (PEP) on three nights in 2008 and by DSLR photometry on three nights in 2014. PEP yielded 51 magnitude measurements in V, including 4 peaks of the light curve, and DSLR photometry yielded 622 measurements, including 14 peaks of the light curve. Fourier analysis of the DSLR photometric data found a principle frequency F1 of 14.8853 (0.0001) c/d, and a harmonic frequency 2F1 of 29.7706 (0.0007) c/d, similar to the results of others. Another frequency F2 of 22.2049 (0.0025) c/d, of much lower amplitude than F1, was identified. F2 is higher than the frequency (19.15 c/d) previously reported in the literature, and its accuracy is regarded as uncertain as the semi-amplitude of F2 is low. Regression analysis of an O-C diagram, plotted from 33 historical times of maximum from 1960 to 2003, 4 times of maximum from our PEP in 2008, and 14 times of maximum light from our DSLR photometry in 2014 indicated that a cubic regression provided the best fit. The fitted curve confirms conclusions of others that the period of ZZ Mic was increasing at a constant rate during the years 1960 to 2003, and indicates that the period has decreased during more recent years. The following cubic ephemeris was derived, with zero epoch defined as the first peak of the DSLR photometry light curve on 19 July 2014: Tmax (HJD) = 2456858.0131 (0.0002) - 7.644 (2.532) • 10-19 E3 - 2.646 (0.973) • 10-13 E2 + 0.06717917 (0.00000001) E.

  20. The sorption property of As(III) and As(V) from aqueous solution using waste cast iron

    NASA Astrophysics Data System (ADS)

    Kim, Wooram; Lee, Yunsub; Kim, Yangsu; Choi, Jinyoung; Han*, Ohhyung

    2015-04-01

    The sorption property of As(III) and As(V) from aqueous solution was investigated using waste cast iron(WCI), which is a byproduct of the iron casting process in foundries. Two types of WCI were used in the experiment: grind precipitate dust (GPD) and cast iron shot (CIS). Non-equilibrium batch experiments were performed under different concentrations of As(III) and As(V). Results showed that waste cast iron was effective in the removal of As(III) and As(V). The phase changes of sorbed As species on the GPD using XPS (X-ray Photoelectron Spectroscopy) were investigated. The results showed the binding energy of 45.19eV for As(V) were obtained, whereas two of 45.3eV and 43.91eV for As(III) were shown in GPD. It can be strongly suggested that GPD mediated As(V) had no evidence for the reduction of ionized As(V) species into As(III), whereas GPD mediated As(III) showed a partial oxidation of As(III) into As(V). The qualitative and quantitative analysis of As distribution and metal containing phase in WCI surface through the XRF, XRD, EPMA, EDS patterns, BSE and SEM image were investigated. The GPD and CIS are a spherical shape with Fe0 composition in correspondence with XRF and XRD analysis results. Quantitative analysis for molar ratio of Fe and As indicated a 1.1% and 1.5% of As(V) and As(III) molar fractions were observed in GPD, while 5.1% and 0.9% fractions in CIS.

  1. Formation and diffusion of vacancy-polaron complex in olivine-type LiMnPO4 and LiFePO4

    NASA Astrophysics Data System (ADS)

    Asari, Yusuke; Suwa, Yuji; Hamada, Tomoyuki

    2011-10-01

    Formation and diffusion of a vacancy-polaron complex in olivine-type cathode-active materials, namely, LiMPO4 (M = Fe, Mn), were theoretically investigated by using the first-principles density functional theory within a framework of GGA + U method. It is shown that a lithium vacancy and a corresponding hole-polaron form the complex at the fully lithiated limit owing to lattice distortion and Coulomb interaction between them. It is also shown that the formation energy of the complex in LiMnPO4 is 0.19 eV higher than that in LiFePO4, since a hole polaron in LiMnPO4 is not sufficiently relaxed. As a result, the nucleation rate of MnPO4 phase in LiMnPO4 is 10-3 times slower than that in LiFePO4 and represents the main difference between the kinetics in the initial stage of charging of the two olivine materials. It was also found that the activation energy of the complex diffusion is limited by vacancy hopping in LiMnPO4, while it is determined by both vacancy hopping and polaron hopping in LiFePO4. The activation energy in LiMnPO4, 0.38 eV, is comparable with that in LiFePO4, 0.42 eV. The calculated potential energy profile, showed that the minimum energy path of the diffusing lithium in LiMnPO4 has the same winding shape as that in LiFePO4.

  2. Electronic Structure and Optical Properties of Cu2ZnGeSe4. First-Principles Calculations and Vacuum-Ultraviolet Spectroscopic Ellipsometric Studies

    SciTech Connect

    Choi, Sukgeun; Park, Ji-Sang; Donohue, Andrea; Christensen, Steven T.; To, Bobby; Beall, Carolyn; Wei, Su-Huai; Repins, Ingid L.

    2015-11-19

    Cu2ZnGeSe4 is of interest for the development of next-generation thin-film photovoltaic technologies. To understand its electronic structure and related fundamental optical properties, we perform first-principles calculations for three structural variations: kesterite, stannite, and primitive-mixed CuAu phases. The calculated data are compared with the room-temperature dielectric functionϵ=ϵ1+iϵ2 spectrum of polycrystalline Cu2ZnGeSe4 determined by vacuum-ultraviolet spectroscopic ellipsometry in the photon-energy range of 0.7 to 9.0 eV. Ellipsometric data are modeled with the sum of eight Tauc-Lorentz oscillators, and the best-fit model yields the band-gap and Tauc-gap energies of 1.25 and 1.19 eV, respectively. A comparison of overall peak shapes and relative intensities between experimental spectra and the calculated ϵ data for three structural variations suggests that the sample may not have a pure (ordered) kesterite phase. We found that the complex refractive index N=n+ik, normal-incidence reflectivity R, and absorption coefficients α are calculated from the modeled ϵ spectrum, which are also compared with those of Cu2ZnSnSe4 . The spectral features for Cu2ZnGeSe4 appear to be weaker and broader than those for Cu2ZnSnSe4 , which is possibly due to more structural imperfections presented in Cu2ZnGeSe4 than Cu2ZnSnSe4 .

  3. Search for resonances decaying to etac pi pi- in two-photon interactions

    SciTech Connect

    Lees, J.P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D.J.; Hearty, C.; Mattison, T.S.; McKenna, J.A.; So, R.Y.; Khan, A.; Blinov, V.E.; /more authors..

    2012-06-18

    We report a study of the process {gamma}{gamma} {yields} X {yields} {eta}{sub c}{pi}{sup +}{pi}{sup -}, where X stands for one of the resonances {chi}{sub c2}(1P), {eta}{sub c}(2S), X(3872), X(3915), or {chi}{sub c2}(2P). The analysis is performed with a data sample of 473.9 fb{sup -1} collected with the BABAR detector at the PEP-II asymmetric-energy electron-positron collider. We do not observe a significant signal for any channel, and calculate 90% confidence-level upper limits on the products of branching fractions and two-photon widths {Lambda}{sub X{yields}{gamma}{gamma}} {Beta}(X {yields} {eta}{sub c}{pi}{sup +}{pi}{sup -}): 15.7 eV for {chi}{sub c2}(1P), 133 eV for {eta}{sub c}(2S), 11.1 eV for X(3872) (assuming it to be a spin-2 state), 16 eV for X(3915) (assuming it to be a spin-2 state), and 19 eV for {chi}{sub c2}(2P). We also report upper limits on the ratios of branching fractions {Beta}({eta}{sub c}(2S) {yields} {eta}{sub c}{pi}{sup +}{pi}{sup -})/{Beta}({eta}{sub c}(2S) {yields} K{sub S}{sup 0}K{sup +}{pi}{sup -}) < 10.0 and {Beta}({chi}{sub c2}(1P) {yields} {eta}{sub c}{pi}{sup +}{pi}{sup -})/{Beta}({chi}{sub c2}(1P) {yields} K{sub S}{sup 0}K{sup +}{pi}{sup -}) < 32.9 at the 90% confidence level.

  4. GIGANTUS1 (GTS1), a member of Transducin/WD40 protein superfamily, controls seed germination, growth and biomass accumulation through ribosome-biogenesis protein interactions in Arabidopsis thaliana

    PubMed Central

    2014-01-01

    Background WD40 domains have been found in a plethora of eukaryotic proteins, acting as scaffolding molecules assisting proper activity of other proteins, and are involved in multi-cellular processes. They comprise several stretches of 44-60 amino acid residues often terminating with a WD di-peptide. They act as a site of protein-protein interactions or multi-interacting platforms, driving the assembly of protein complexes or as mediators of transient interplay among other proteins. In Arabidopsis, members of WD40 protein superfamily are known as key regulators of plant-specific events, biologically playing important roles in development and also during stress signaling. Results Using reverse genetic and protein modeling approaches, we characterize GIGANTUS1 (GTS1), a new member of WD40 repeat protein in Arabidopsis thaliana and provide evidence of its role in controlling plant growth development. GTS1 is highly expressed during embryo development and negatively regulates seed germination, biomass yield and growth improvement in plants. Structural modeling analysis suggests that GTS1 folds into a β-propeller with seven pseudo symmetrically arranged blades around a central axis. Molecular docking analysis shows that GTS1 physically interacts with two ribosomal protein partners, a component of ribosome Nop16, and a ribosome-biogenesis factor L19e through β-propeller blade 4 to regulate cell growth development. Conclusions Our results indicate that GTS1 might function in plant developmental processes by regulating ribosomal structural features, activities and biogenesis in plant cells. Our results suggest that GIGANTUS1 might be a promising target to engineer transgenic plants with higher biomass and improved growth development for plant-based bioenergy production. PMID:24467952

  5. Very high energy gamma rays from active galactic nuclei: Cascading on the cosmic background radiation fields and the formation of pair halos

    NASA Technical Reports Server (NTRS)

    Aharonian, F. A.; Coppi, P. S.; Voelk, H. J.

    1994-01-01

    Recent high-energy gamma-ray observations (E(sub gamma) greater than 100 MeV) of blazar Active Galactic Nuclei (AGNs) show emission spectra with no clear upper energy cutoff. AGNs, considered to be possible sources for the observed flux of cosmic rays beyond 10(exp 19) eV, may well have emission extending into the very high energy (VHE), (E(sub gamma) greater than 100 GeV) domain. Because VHE gamma-rays are absorbed by pair production on the intergalactic background radiation fields, much of this emission may not be directly visible. The electromagnetic cascades initiated by absorbed VHE gamma-rays, however, may be observable. Since, most probably, the velocities of (e(+), e(-)) pairs produced in a cascade are quickly isotropized by an ambient random magnetic field, extended 'halos' (R greater than 1 Mpc) of pairs will be formed around AGNs with VHE emission. The cascade radiation from these pair halos is emitted isotropically and should be observable at energies below a few TeV. The halo radiation can be distinguished by its characteristic variation in spectrum and intensity with angular distance from the central source. This variation depends weakly on the details of the central source model, e.g., the orientation and beaming/opening angle of an emitting jet. Limiting or determining the intensity of the pair halo can thus serve as a model-independent bound on or measure of the VHE power of AGNs. Next-generation Cherenkov telescopes may be able to image a pair halo.

  6. Antigenic Properties of the HIV Envelope on Virions in Solution

    PubMed Central

    Mengistu, Meron; Lewis, George K.; Lakowicz, Joseph R.

    2014-01-01

    The structural flexibility found in human immunodeficiency virus (HIV) envelope glycoproteins creates a complex relationship between antigenicity and sensitivity to antiviral antibodies. The study of this issue in the context of viral particles is particularly problematic as conventional virus capture approaches can perturb antigenicity profiles. Here, we employed a unique analytical system based on fluorescence correlation spectroscopy (FCS), which measures antibody-virion binding with all reactants continuously in solution. Panels of nine anti-envelope monoclonal antibodies (MAbs) and five virus types were used to connect antibody binding profiles with neutralizing activities. Anti-gp120 MAbs against the 2G12 or b12 epitope, which marks functional envelope structures, neutralized viruses expressing CCR5-tropic envelopes and exhibited efficient virion binding in solution. MAbs against CD4-induced (CD4i) epitopes considered hidden on functional envelope structures poorly bound these viruses and were not neutralizing. Anti-gp41 MAb 2F5 was neutralizing despite limited virion binding. Similar antigenicity patterns occurred on CXCR4-tropic viruses, except that anti-CD4i MAbs 17b and 19e were neutralizing despite little or no virion binding. Notably, anti-gp120 MAb PG9 and anti-gp41 MAb F240 bound to both CCR5-tropic and CXCR4-tropic viruses without exerting neutralizing activity. Differences in the virus production system altered the binding efficiencies of some antibodies but did not enhance antigenicity of aberrant gp120 structures. Of all viruses tested, only JRFL pseudoviruses showed a direct relationship between MAb binding efficiency and neutralizing potency. Collectively, these data indicate that the antigenic profiles of free HIV particles generally favor the exposure of functional over aberrant gp120 structures. However, the efficiency of virion-antibody interactions in solution inconsistently predicts neutralizing activity in vitro. PMID:24284318

  7. Boron-doped cadmium oxide composite structures and their electrochemical measurements

    SciTech Connect

    Lokhande, B.J.; Ambare, R.C.; Mane, R.S.; Bharadwaj, S.R.

    2013-08-01

    Graphical abstract: Conducting nano-fibrous 3% boron doped cadmium oxide thin films were prepared by SILAR and its super capacitive properties were studied. - Highlights: • Samples are of nanofibrous nature. • All samples shows pseudocapacitive behavior. • 3% B doped CdO shows good specific capacitance. • 3% B doped CdO shows maximum 74.93% efficiency at 14 mA/cm{sup 2}. • 3% B doped CdO shows 0.8 Ω internal resistance. - Abstract: Boron-doped and undoped cadmium oxide composite nanostructures in thin film form were prepared onto stainless steel substrates by a successive ionic layer adsorption and reaction method using aqueous solutions of cadmium nitrate, boric acid and 1% H{sub 2}O{sub 2}. As-deposited films were annealed at 623 K for 1 h. The X-ray diffraction study shows crystalline behavior for both doped and undoped films with a porous topography and nano-wires type architecture, as observed in SEM image. Wettability test confirms the hydrophilic surface with 58° contact angle value. Estimated band gap energy is around 1.9 eV. Electrochemical behavior of the deposited films is attempted in 1 M KOH electrolyte using cyclic voltammetry (CV), electrochemical impedance spectroscopy and galvanostatic charge–discharge tests. Maximum values of the specific capacitance, specific energy and specific power obtained for 3% B doped CdO film at 2 mV/s scan rate are 20.05 F/g, 1.22 Wh/kg and 3.25 kW/kg, respectively.

  8. Vitamin D Depletion in Pregnancy Decreases Survival Time, Oxygen Saturation, Lung Weight and Body Weight in Preterm Rat Offspring.

    PubMed

    Lykkedegn, Sine; Sorensen, Grith Lykke; Beck-Nielsen, Signe Sparre; Pilecki, Bartosz; Duelund, Lars; Marcussen, Niels; Christesen, Henrik Thybo

    2016-01-01

    Animal studies suggest a role of vitamin D in fetal lung development although not studied in preterm animals. We tested the hypothesis that vitamin D depletion aggravates respiratory insufficiency in preterm rat offspring. Furthermore, the effects of vitamin D depletion on growth and lung surfactant were investigated. Female Sprague-Dawley rats were randomly assigned low vitamin D (VDL) or control diet before mating and followed with serum 25-hydroxyvitamin D (s-25(OH)D) determinations. After cesarean section at gestational day 19 (E19) or day 22 (E22), placental weight, birth weight, crown-rump-length (CRL), oxygenation (SaO2) at 30 min and survival time were recorded. The pup lungs were analyzed for phospholipid levels, surfactant protein A-D mRNA and the expression of the vitamin D receptor (VDR). S-25(OH)D was significantly lower in the VDL group at cesarean section (12 vs. 30nmol/L, p<0.0001). Compared to the controls, E19 VDL pups had lower birth weight (2.13 vs. 2.29g, p<0.001), lung weight (0.09 vs. 0.10g, p = 0.002), SaO2 (54% vs. 69%, p = 0.002) as well as reduced survival time (0.50 vs. 1.25h, p<0.0001). At E22, the VDL-induced pulmonary differences were leveled out, but VDL pups had lower CRL (4.0 vs. 4.5cm, p<0.0001). The phospholipid levels and the surfactant protein mRNA expression did not differ between the dietary groups. In conclusion, Vitamin D depletion led to lower oxygenation and reduced survival time in the preterm offspring, associated with reduced lung weight and birth weight. Further studies of vitamin D depletion in respiratory insufficiency in preterm neonates are warranted. PMID:27571350

  9. BLAZARS AS ULTRA-HIGH-ENERGY COSMIC-RAY SOURCES: IMPLICATIONS FOR TeV GAMMA-RAY OBSERVATIONS

    SciTech Connect

    Murase, Kohta; Dermer, Charles D.; Takami, Hajime; Migliori, Giulia

    2012-04-10

    The spectra of BL Lac objects and Fanaroff-Riley I radio galaxies are commonly explained by the one-zone leptonic synchrotron self-Compton (SSC) model. Spectral modeling of correlated multiwavelength data gives the comoving magnetic field strength, the bulk outflow Lorentz factor, and the emission region size. Assuming the validity of the SSC model, the Hillas condition shows that only in rare cases such sources accelerate protons to much above 10{sup 19} eV, so {approx}> 10{sup 20} eV ultra-high-energy cosmic rays (UHECRs) are likely to be heavy ions if powered by this type of radio-loud active galactic nuclei (AGNs). Survival of nuclei is shown to be possible in TeV BL Lacs and misaligned counterparts with weak photohadronic emissions. Another signature of hadronic production is intergalactic UHECR-induced cascade emission, which is an alternative explanation of the TeV spectra of some extreme non-variable blazars such as 1ES 0229+200 or 1ES 1101-232. We study this kind of cascade signal, taking into account effects of the structured extragalactic magnetic fields in which the sources should be embedded. We demonstrate the importance of cosmic-ray deflections on the {gamma}-ray flux, and show that required absolute cosmic-ray luminosities are larger than the average UHECR luminosity inferred from UHECR observations and can even be comparable to the Eddington luminosity of supermassive black holes. Future TeV {gamma}-ray observations using the Cerenkov Telescope Array and the High Altitude Water Cerenkov detector array can test for UHECR acceleration by observing >25 TeV photons from relatively low redshift sources such as 1ES 0229+200, and {approx}>TeV photons from more distant radio-loud AGNs.

  10. Experimental investigation of moving surfaces for boundary layer and circulation control of airfoils and wings

    NASA Astrophysics Data System (ADS)

    Vets, Robert

    An experimental study was conducted to assess the application of a moving surface to affect boundary layers and circulation around airfoils for the purpose of altering and enhancing aerodynamic performance of finite wings at moderate Reynolds numbers. The moving surface was established by a wide, lightweight, nylon belt that enveloped a wing's symmetric airfoil profile articulated via a friction drive cylinder such that the direction of the upper surface was in the direction of the free stream. A water tunnel visualization study accompanied wind tunnel testing at the University of Washington, Kirsten Wind Tunnel of finite wings. An experimental study was conducted to assess the application of a moving surface to affect boundary layers and circulation around airfoils for the purpose of altering and enhancing aerodynamic performance of finite wings at moderate Reynolds numbers. The moving surface was established by a wide, lightweight, nylon belt that enveloped a wing's symmetric airfoil profile articulated via a friction drive cylinder such that the direction of the upper surface was in the direction of the free stream. A water tunnel visualization study accompanied wind tunnel testing at the University of Washington, Kirsten Wind Tunnel of finite wings. The defining non-dimensional parameter for the system is the ratio of the surface velocity to the free stream velocity, us/Uo. Results show a general increase in lift with increasing us/Uo. The endurance parameter served as an additional metric for the system's performance. Examining the results of the endurance parameter shows general increase in endurance and lift with the moving surface activated. Peak performance in terms of increased endurance along with increased lift occurs at or slightly above us/Uo = 1. Water tunnel visualization showed a marked difference in the downwash for velocity ratios greater than 1, supporting the measured data. Reynolds numbers for this investigation were 1.9E5 and 4.3E5, relevant to the class of fixed wing, Tier-1, Unmanned Aerial Vehicles (UAV).

  11. Repetitive auditory stimulation at a critical prenatal period modulates the postnatal functional development of the auditory as well as visual system in chicks (Gallus domesticus).

    PubMed

    Roy, Saborni; Nag, Tapas C; Upadhyay, Ashish Datt; Mathur, Rashmi; Jain, Suman

    2013-09-01

    The extrinsic sensory stimulation plays a crucial role in the formation and integration of sensory modalities during development. Postnatal behavior is thereby influenced by the type and timing of presentation of prenatal sensory stimuli. In this study, fertilized eggs of white Leghorn chickens during incubation were exposed to either species-specific calls or no sound. To find the prenatal critical period when auditory stimulation can modulate visual system development, the former group was divided into three subgroups: in subgroup A (SGA), the stimulus was provided during embryonic day (E)10 to E16, in SGB E17- hatching, and in SGC E10-hatching. The auditory and visual perceptual learning was recorded at posthatch day (PH) 1-3, whereas synaptic plasticity (evident from synaptophysin and PSD-95 expression), was observed at E19, E20, and PH 1-3. An increased number of responders were observed in both auditory and visual preference tests at PH 1 following stimulation. Although a decrease in latency of entry and an increase in total time spent were observed in all stimulated groups, it was most significant in SGC in auditory preference and in SGB and SGC in visual preference test. The auditory cortex of SGC and visual Wulst of SGB and SGC revealed higher expression of synaptic proteins, compared to control and SGA. A significant inter-hemispheric and gender-based difference in expression was also found in all groups. These results indicate facilitation of postnatal behaviour and synaptogenesis in both auditory and visual systems following prenatal repetitive auditory stimulation, only when given during prenatal critical period of development. PMID:23696545

  12. Hydrogen Passivation of N(+)P and P(+)N Heteroepitaxial InP Solar Cell Structures

    NASA Technical Reports Server (NTRS)

    Chatterjee, B.; Davis, W. C.; Ringel, S. A.; Hoffman, R., Jr.

    1995-01-01

    Dislocations and related point defect complexes caused by lattice mismatch currently limit the performance of heteroepitaxial InP cells by introducing shunting paths across the active junction and by the formation of deep traps within the base region. We have previously demonstrated that plasma hydrogenation is an effective and stable means to passivate the electrical activity of such defects in specially designed heteroepitaxial InP test structures to probe hydrogen passivation at typical base depths within a cell structure. In this work, we present our results on the hydrogen passivation of actual heteroepitaxial n(+)p and p(+)n InP cell structures grown on GaAs substrates by metalorganic chemical vapor deposition (MOCVD). We have found that a 2 hour exposure to a 13.56 MHz hydrogen plasma at 275 C reduces the deep level concentration in the base regions of both n(+)p and p(+)n heteroepitaxial InP cell structures from as-grown values of 5 - 7 x 10(exp 14)/cc, down to 3 - 5 x 10(exp 12)/cc. All dopants were successfully reactivated by a 400 C, 5 minute anneal With no detectable activation of deep levels. I-V analysis indicated a subsequent approx. 100 fold decrease In reverse leakage current at -1 volt reverse bias, and an improved built in voltage for the p(+)n structures. ln addition to being passivated,dislocations are also shown to participate in secondary interactions during hydrogenation. We find that the presence of dislocations enhances hydrogen diffusion into the cell structure, and lowers the apparent dissociation energy of Zn-H complexes from 1.19 eV for homoepitaxial Zn-doped InP to 1.12 eV for heteroepitaxial Zn-doped InP. This is explained by additional hydrogen trapping at dislocations subsequent to the reactivation of Zn dopants after hydrogenation.

  13. Hydrogen passivation of N(+)-P and P(+)-N heteroepitaxial InP solar cell structures

    NASA Technical Reports Server (NTRS)

    Chatterjee, Basab; Davis, William C.; Ringel, Steve A.; Hoffman, Richard, Jr.

    1996-01-01

    Dislocations and related point defect complexes caused by lattice mismatch currently limit the performance of heteroepitaxial InP cells by introducing shunting paths across the active junction and by the formation of deep traps within the base region. We have previously demonstrated that plasma hydrogenation is an effective and stable means to passivate the electrical activity of such defects in specially designed heteroepitaxial InP test structures to probe hydrogen passivation at typical base depths within a cell structure. In this work, we present our results on the hydrogen passivation of actual heteroepitaxial n-p and p-n InP cell structures grown on GaAs substrates by metalorganic chemical vapor deposition (MOCVD). We have found that a 2 hour exposure to a 13.56 MHz hydrogen plasma at 275 C reduces the deep level concentration in the base regions of both n(+)-p and p(+)-n heteroepitaxial InP cell structures from as-grown values of 5-7 x 10(exp 14) cm(exp -3), down to 3-5 x 10(exp 12) cm(exp -3). All dopants were successfully reactivated by a 400 C, 5 minute anneal with no detectable activation of deep levels. One to five analysis indicated a subsequent approximately 100 fold decrease in reverse leakage current at -1 volt reverse bias, and an improved built in voltage for the p(+)-n structures. In addition to being passivated, dislocations are also shown to participate in secondary interactions during hydrogenation. We find that the presence of dislocations enhances hydrogen diffusion into the cell structure, and lowers the apparent dissociation energy of Zn-H complexes from 1.19 eV for homoepitaxial Zn-doped InP to 1.12 eV for heteroepitaxial Zn-doped InP. This is explained by additional hydrogen trapping at dislocations subsequent to the reactivation of Zn dopants after hydrogenation.

  14. Geomicrobiology of subglacial meltwater samples from Store Landgletscher and Russell Glacier, West Greenland

    NASA Astrophysics Data System (ADS)

    Cameron, K. A.; Dieser, M.; Choquette, K.; Christner, B. C.; Hagedorn, B.; Harrold, Z.; Liu, L.; Sletten, R. S.; Junge, K.

    2012-12-01

    The melting of the Greenland Ice Sheet provides direct connections between atmospheric, supraglacial and subglacial environments. The intraglacial hydrological pathways that result are believed to accommodate the microbial colonization of subglacial environments; however, little is known about the abundance, diversity and activity of microorganisms within these niches. The Greenland Ice Sheet (1.7 million square kilometers) and its associated surpaglacial and subglacial ecosystems may contribute significantly to biogeochemical cycling processes. We analyzed subglacial microbial assemblages in subglacial outflows, near Thule and Kangerlussuaq, West Greenland. The investigative approach included correlating microbial diversity, inferred function, abundance, melt water chemistry, O-18 water isotope ratios, alkalinity and sediment load. Using Illumina sequencing, bacterial small subunit ribosomal RNA hypervariable regions have been targeted and amplified from both extracted DNA and reverse transcribed rRNA. Over 3 billion sequence reads have been generated to create a comprehensive diversity profile. Total abundances ranged from 2.24E+04 to 1.58E+06 cells mL-1. In comparison, the total abundance of supraglacial early season snow samples ranged from 3.35E+02 to 2.8E+04 cells mL-1. 65 % of samples incubated with cyano ditoyl tetrazolium chloride (CTC), used to identify actively respiring cells, contained CTC-positive cells. On average, these cells represented 1.9 % of the estimated total abundance (1.86E+02 to 2.19E+03 CTC positive cells mL-1; 1.39E+03 cells mL-1 standard deviation); comparative to those measured in temperate freshwater lakes. The overarching objective of our research is to provide data that indicates the role of microbial communities, associated with ice sheets, in elemental cycling and in the release of biomass and nutrients to the surrounding marine biome.

  15. Vitamin D Depletion in Pregnancy Decreases Survival Time, Oxygen Saturation, Lung Weight and Body Weight in Preterm Rat Offspring

    PubMed Central

    Lykkedegn, Sine; Sorensen, Grith Lykke; Beck-Nielsen, Signe Sparre; Pilecki, Bartosz; Duelund, Lars; Marcussen, Niels; Christesen, Henrik Thybo

    2016-01-01

    Animal studies suggest a role of vitamin D in fetal lung development although not studied in preterm animals. We tested the hypothesis that vitamin D depletion aggravates respiratory insufficiency in preterm rat offspring. Furthermore, the effects of vitamin D depletion on growth and lung surfactant were investigated. Female Sprague-Dawley rats were randomly assigned low vitamin D (VDL) or control diet before mating and followed with serum 25-hydroxyvitamin D (s-25(OH)D) determinations. After cesarean section at gestational day 19 (E19) or day 22 (E22), placental weight, birth weight, crown-rump-length (CRL), oxygenation (SaO2) at 30 min and survival time were recorded. The pup lungs were analyzed for phospholipid levels, surfactant protein A-D mRNA and the expression of the vitamin D receptor (VDR). S-25(OH)D was significantly lower in the VDL group at cesarean section (12 vs. 30nmol/L, p<0.0001). Compared to the controls, E19 VDL pups had lower birth weight (2.13 vs. 2.29g, p<0.001), lung weight (0.09 vs. 0.10g, p = 0.002), SaO2 (54% vs. 69%, p = 0.002) as well as reduced survival time (0.50 vs. 1.25h, p<0.0001). At E22, the VDL-induced pulmonary differences were leveled out, but VDL pups had lower CRL (4.0 vs. 4.5cm, p<0.0001). The phospholipid levels and the surfactant protein mRNA expression did not differ between the dietary groups. In conclusion, Vitamin D depletion led to lower oxygenation and reduced survival time in the preterm offspring, associated with reduced lung weight and birth weight. Further studies of vitamin D depletion in respiratory insufficiency in preterm neonates are warranted. PMID:27571350

  16. Supercontinuum spatial modulation spectroscopy: Detection and noise limitations

    SciTech Connect

    McDonald, M. P.; Vietmeyer, F.; Kuno, M.; Aleksiuk, D.

    2013-11-15

    Supercontinuum spatial modulation spectroscopy is a facile tool for conducting single molecule/particle extinction spectroscopy throughout the visible and near infrared (420–1100 nm). The technique's capabilities are benchmarked using individual Au nanoparticles (NPs) as a standard since they are well studied and display a prominent plasmon resonance in the visible. Extinction spectra of individual Au NPs with diameters (d) ranging from d ∼ 8 to 40 nm are resolved with extinction cross sections (σ{sub ext}) of σ{sub ext} ∼1 × 10{sup −13}–1 ×10{sup −11} cm{sup 2}. Corresponding signal-to-noise ratios range from ∼30 to ∼1400. The technique's limit of detection is determined to be 4.3 × 10{sup −14} cm{sup 2} (4.3 nm{sup 2}). To showcase supercontinuum spatial modulation spectroscopy's broader applicability, extinction spectra are acquired for other model systems, such as individual single-walled carbon nanotubes (SWCNTs) and CdSe nanowires. We show for the first time extinction spectra of individual (8,3) and (6,5) SWCNTs. For both chiralities, their E{sub 11} [(8,3) 1.30 eV (952 nm); (6,5) 1.26 eV (986 nm)] and E{sub 22} [(8,3) 1.86 eV (667 nm); (6,5) 2.19 eV (567 nm)] excitonic resonances are seen with corresponding cross sections of σ{sub ext} ∼ 10{sup −13} cm{sup 2} μm{sup −1}.

  17. Influence of Coding Variability in APP-Aβ Metabolism Genes in Sporadic Alzheimer's Disease.

    PubMed

    Sassi, Celeste; Ridge, Perry G; Nalls, Michael A; Gibbs, Raphael; Ding, Jinhui; Lupton, Michelle K; Troakes, Claire; Lunnon, Katie; Al-Sarraj, Safa; Brown, Kristelle S; Medway, Christopher; Lord, Jenny; Turton, James; Morgan, Kevin; Powell, John F; Kauwe, John S; Cruchaga, Carlos; Bras, Jose; Goate, Alison M; Singleton, Andrew B; Guerreiro, Rita; Hardy, John

    2016-01-01

    The cerebral deposition of Aβ42, a neurotoxic proteolytic derivate of amyloid precursor protein (APP), is a central event in Alzheimer's disease (AD)(Amyloid hypothesis). Given the key role of APP-Aβ metabolism in AD pathogenesis, we selected 29 genes involved in APP processing, Aβ degradation and clearance. We then used exome and genome sequencing to investigate the single independent (single-variant association test) and cumulative (gene-based association test) effect of coding variants in these genes as potential susceptibility factors for AD, in a cohort composed of 332 sporadic and mainly late-onset AD cases and 676 elderly controls from North America and the UK. Our study shows that common coding variability in these genes does not play a major role for the disease development. In the single-variant association analysis, the main hits, none of which statistically significant after multiple testing correction (1.9e-4

  18. Influence of Coding Variability in APP-Aβ Metabolism Genes in Sporadic Alzheimer’s Disease

    PubMed Central

    Sassi, Celeste; Ridge, Perry G.; Nalls, Michael A.; Gibbs, Raphael; Ding, Jinhui; Lupton, Michelle K.; Troakes, Claire; Lunnon, Katie; Al-Sarraj, Safa; Brown, Kristelle S.; Medway, Christopher; Lord, Jenny; Turton, James; Morgan, Kevin; Powell, John F.; Kauwe, John S.; Cruchaga, Carlos; Bras, Jose; Goate, Alison M.; Singleton, Andrew B.; Guerreiro, Rita; Hardy, John

    2016-01-01

    The cerebral deposition of Aβ42, a neurotoxic proteolytic derivate of amyloid precursor protein (APP), is a central event in Alzheimer’s disease (AD)(Amyloid hypothesis). Given the key role of APP-Aβ metabolism in AD pathogenesis, we selected 29 genes involved in APP processing, Aβ degradation and clearance. We then used exome and genome sequencing to investigate the single independent (single-variant association test) and cumulative (gene-based association test) effect of coding variants in these genes as potential susceptibility factors for AD, in a cohort composed of 332 sporadic and mainly late-onset AD cases and 676 elderly controls from North America and the UK. Our study shows that common coding variability in these genes does not play a major role for the disease development. In the single-variant association analysis, the main hits, none of which statistically significant after multiple testing correction (1.9e-4

  19. Short latency vestibular evoked potentials in the chicken embryo

    NASA Technical Reports Server (NTRS)

    Jones, S. M.; Jones, T. A.

    1996-01-01

    Electrophysiological responses to pulsed linear acceleration stimuli were recorded in chicken embryos incubated for 19 or 20 days (E19/E20). Responses occurred within the first 16 ms following the stimulus onset. The evoked potentials disappeared following bilateral labyrinthectomy, but persisted following cochlear destruction alone, thus demonstrating that the responses were vestibular. Approximately 8 to 10 response peaks could be identified. The first 4 positive and corresponding negative components (early peaks with latencies < 6.0 ms) were scored and latencies and amplitudes quantified. Vestibular response latencies were significantly longer (P < 0.01) and amplitudes significantly smaller (P < 0.001) than those observed in 2-week-old birds. Mean response threshold for anesthetized embryos was -15.9dBre 1.0 g/ms, which was significantly higher (P < 0.03) than those observed in 2-week-old birds (-23.0dBre 1.0 g/ms). Latency/intensity functions (that is, slopes) were not significantly different between embryos and 2-week-old animals, but amplitude/intensity functions for embryos were significantly shallower than those for 2-week-old birds (P < 0.001). We presume that these differences reflect the refinement of sensory function that occurs following 19 to 20 days of incubation. The recording of vestibular evoked potentials provides an objective, direct and noninvasive measure of peripheral vestibular function in the embryo and, as such, the method shows promise as an investigative tool. The results of the present study form the definitive basis for using vestibular evoked potentials in the detailed study of avian vestibular ontogeny and factors that may influence it.

  20. Neutron capture in s-wave resonances of iron-56, nickel-58, and nickel-60

    SciTech Connect

    Wisshak, K.; Fabbri, F.; Kappeler, F.; Reffo, G.

    1984-02-01

    The neutron capture widths of s-wave resonances in /sup 56/Fe (27.7 keV), /sup 58/Ni (15.4 keV), and /sup 60/Ni (12.5 keV) have been determined using a setup completely different from previous experiments. A pulsed 3-MV Van de Graaff accelerator and a kinematically collimated neutron beam, produced via the /sup 7/Li(p,n) reaction, were used in the experiments. Capture gamma rays were observed by three Moxon-Rae detectors with graphite, bismuth-graphite, and bismuth converters, respectively. The samples were positioned at a neutron flight path of only 9 cm. Thus, events due to capture of resonance-scattered neutrons in the detectors or in surrounding materials are completely discriminated by their additional time of flight. The high neutron flux at the sample position allowed the use of very thin samples (0.15 to 0.45 mm), avoiding large multiple scattering corrections. The data obtained with the individual detectors were corrected for the efficiency of the respective converter materials. For that purpose, detailed theoretical calculations of the capture gamma-ray spectra of the measured isotopes and of gold, which was used as a standard, were performed. The final results are GAMMA /SUB lg/ (27.7 keV, /sup 56/Fe) = 1.06 + or - 0.05 eV; GAMMA..gamma..(15.4 keV, /sup 58/Ni) = 1.53 + or - 0.10 eV; and GAMMA..gamma..(12.5 keV, /sup 60/Ni) = 2.92 + or - 0.19 eV. The accuracy obtained with the present experimental method represents an improvement by a factor 3 to 6 compared to previous experiments. The investigated s-wave resonances contribute 10 to 40% to the total capture rate of the respective isotopes in a typical fast reactor.

  1. Ocean circulation in the southern Benguela region from the Pliocene to the Pleistocene: tracking Agulhas leakage into the SE Atlantic

    NASA Astrophysics Data System (ADS)

    Petrick, Benjamin; McClymont, Erin; Felder, Sojna; Leng, Melanie

    2013-04-01

    The transition from the warmth of the middle Pliocene to the large amplitude, 100 kyr glacial-interglacial cycles of the late Pleistocene provides a way to understand the forcings and impacts of regional and global climate change. Here, we investigate changes in ocean circulation over the period from 3.5 Ma to present using a marine sediment core, ODP Site 1087 (31o28'S, 15o19'E, 1374m water depth). ODP 1087 is located in the South-east Atlantic Ocean, outside the Benguela upwelling region. Its location allows investigation of the history of the heat and salt transfer to the Atlantic Ocean from the Indian Ocean ("Agulhas leakage"), which plays an important part in the global thermohaline circulation. It is not known how this transfer reacted to generally warmer global temperatures during the mid-Pliocene, nor to the transition to a globally cooler climate in the early Pleistocene. Our approach is to apply several organic geochemistry proxies and foraminiferal analyses to reconstruct the history of ODP 1087. These include the U37K' index to reconstruct sea surface temperatures, pigment analysis for understanding productivity changes, and foraminifera assemblage analysis to detect the presence of different water masses at the site. We have identified changes in SSTs and biological productivity that we argue to reflect shifts in the position of the Benguela upwelling cells, and a changing influence of Agulhas leakage. Our new data reveal a different organization in the Southeast Atlantic. It shows that during the Pliocene ODP 1087 was dominated by Benguela upwelling which had shifted south. We find no evidence for Agulhas leakage during the mid Pliocene, which could mean that Agulhas Leakage was severely reduced during the mid Pliocene. The implications of these results for understanding Plio-Pleistocene climate changes will be explored here.

  2. Exploiting multi-proxy analysis of marine sediments in the southeast Atlantic: Intensification of Agulhas leakage tied to the start of the 100ka cycles.

    NASA Astrophysics Data System (ADS)

    Petrick, Benjamin; McClymont, Erin; Marret, Fabienne

    2013-04-01

    The transition in orbital forcing from a 41 ka world to a 100 ka world was a major change in the climate regime over the last 1.5 Ma but its causes and its impacts are still being investigated. Here, we present reconstructions of sea-surface temperature (SST), salinity, and plankton assemblages obtained from a single core, ODP site 1087 (31°28'S, 15°19'E, 1374m water depth) spanning the last 1.5 Ma. Our hypothesis is that the response and position of the Agulhas leakage, which transfers heat and salt to the SE Atlantic region, has shifted as a result of changes in the dominant periodicity of orbital forcing. We draw on evidence from the alkenone (U37K') proxy for SST, dinoflagllate species analysis, and foraminifera oxygen isotopes for salinity and ice volume, to identify changes in the input of the Agulhas leakage to the SE Atlantic. We present the first continuous record of SE Atlantic SSTs reaching to 1.5 Ma which spans both the 41 kyr and 100 kyr glacial cycles. We identify large changes in SST and salinity on glacial-interglacial timescales, but show that there is a consistent pattern of SSTs leading salinity and then global ice volume change, so that deglaciation occurs some 5-10 kyr after the onset of rapid warming in the SE Atlantic during the recent glacials and interglacials. This early warming pattern, which characterizes the most recent cycles, began to develop as early at 900 ka, as the 100 kyr cycles became dominant. Before this time there is little evidence of Agulhas leakage in the ODP1087 record. We also show that over the last 600 ka there has been a strengthening of the Agulhas Leakage which has led to warmer interglacials over this time period. Overall the record shows that the strength and location of the Agulhas leakage is sensitive to changes in the dominant cycles in the climate.

  3. Changes in ocean circulation in the South-east Atlantic Ocean during the Pliocene

    NASA Astrophysics Data System (ADS)

    Petrick, B. F.; McClymont, E.; Felder, S.; Leng, M. J.

    2013-12-01

    The Southeast Atlantic Ocean is an important ocean gateway because major oceanic systems interact with each other in a relatively small geographic area. These include the Benguela Current, Antarctic Circumpolar Current, and the input of warm and saline waters from the Indian Ocean via the Agulhas leakage. However, there remain questions about circulation change in this region during the Pliocene, including whether there was more or less Agulhas Leakage, which may have implications for the strength of the global thermohaline circulation. ODP Site 1087 (31°28'S, 15°19'E, 1374m water depth) is located outside the Benguela upwelling region and is affected by Agulhas leakage in the modern ocean. Sea-surface temperatures (SSTs) are thus sensitive to the influence of Agulhas Leakage at this site. Our approach is to apply several organic geochemistry proxies and foraminiferal analyses to reconstruct the Pliocene history of ODP 1087, including the UK37' index (SSTs), pigments (primary productivity) and planktonic foraminifera (water mass changes). SSTs during the Pliocene range from 17 to 22.5 °C (mean SSTs at 21 °C), and show variability on orbital and suborbital time scales. Our results indicate that the Benguela upwelling system had intensified and/or shifted south during the Pliocene. We find no evidence of Agulhas leakage, meaning that either Agulhas Leakage was severely reduced or displaced during the mid-Pliocene. Potential causes of the observed signals include changes to the local wind field and/or changes in the temperature of intermediate waters which upwell in the Benguela system. Pronounced cooling is observed during cold stages in the Pliocene, aligned with the M2 and KM2 events. These results may indicate that changes to the extent of the Antarctic ice sheet had impact on circulation in the south east Atlantic during the Pliocene via displacement of the Antarctic Circumpolar Currents.

  4. Pliocene Warm Period Upwelling in the Southern Benguela Region

    NASA Astrophysics Data System (ADS)

    Petrick, B. F.; McClymont, E.; Felder, S.; Leng, M. J.; Rosell Mele, A.; Rueda, G.

    2014-12-01

    The mid-Pliocene has been proposed as a possible analogue for understanding future climate change and testing climate models. Previous work has shown that during the Pliocene the major upwelling systems were relatively warm, and thus either inactive, contracted, or upwelling warmer waters than present. Here we examine evidence from a core site located on the margins of the modern Benguela upwelling system, to test whether the upwelling cells had migrated or contracted relative to present during the Pliocene. We applied several organic geochemistry proxies and foraminiferal analyses to reconstruct the Pliocene history of ODP site 1087 (31º28'S, 15º19'E, 1374m water depth), including the UK37' index and TEX86 index (for reconstructing sea surface temperatures), chlorins (for estimating primary productivity) and planktonic foraminifera assemblages (for inferring water mass changes). These proxies show that between 3.5 and 3.0 Ma the southern Benguela region was significantly cooler than the northern Benguela region, the latter where the main upwelling cells are found today. Coupled with higher primary production, a shift in planktonic foraminifera assemblage, and an offset between the UK37' index and TEX86 index, we infer that more extensive upwelling was present in the southern Benguela region during the Pliocene. We infer that the main Benguela upwelling cells had shifted southward relative to today, as a result of changes in the local wind field. We find evidence for pronounced cooling and a shift in the planktonic foraminifera assemblage during the M2 and KM2 glacial stages, showing a sensitivity of Benguela upwelling to these short-lived climate events.

  5. Genetic variation at the delta-sarcoglycan (SGCD) locus elevates heritable sympathetic nerve activity in human twin pairs

    PubMed Central

    Hightower, C. Makena; Zhang, Kuixing; Miramontes-González, José Pablo; Rao, Fangwen; Wei, Zhiyun; Schork, Andrew J.; Nievergelt, Caroline M.; Biswas, Nilima; Mahata, Manjula; Elkelis, Nina; Taupenot, Laurent; Stridsberg, Mats; Ziegler, Michael G.; O'Connor, Daniel T.

    2013-01-01

    The Syrian Cardiomyopathic Hamster (BIO-14.6/53.58 strains) model of cardiac failure, resulting from naturally occurring deletion at the SGCD (delta-sarcoglycan) locus, displays widespread disturbances in catecholamine metabolism. Rare Mendelian myopathy disorders of human SGCD occur, though common naturally occurring SGCD genetic variation has not been evaluated for effects on human norepinephrine (NE) secretion. This study investigated the effect of SGCD genetic variation on control of NE secretion in healthy twin pairs. Genetic associations profiled SNPs across the SGCD locus. Trait heritability (h2) and genetic covariance (pleiotropy; shared h2) were evaluated. Sympathochromaffin exocytosis in vivo was probed in plasma by both catecholamines and CHGB. Plasma NE is substantially heritable (P=3.19E-16, at 65.2±5.0% of trait variance), sharing significant (P<0.05) genetic determination with circulating and urinary catecholamines, CHGB, eGFR and several cardio-metabolic traits. Participants with higher pNE showed significant (P<0.05) differences in several traits, including increased BP and hypertension risk factors. Peak SGCD variant rs1835919 predicted elevated systemic vascular compliance, without changes in specifically myocardial traits. We used a chimeric regulated secretory pathway photoprotein (CHGA-EAP) to evaluate the effect of SGCD on the exocytotic pathway in transfected PC12 cells; in transfected cells, expression of SGCD augmented CHGA trafficking into the exocytotic regulated secretory pathway. Thus our investigation determined human NE secretion to be a highly heritable trait, influenced by common genetic variation within the SGCD locus. Circulating NE aggregates with BP and hypertension risk factors. Additionally, coordinate NE and CHGB elevation by rs1835919 implicates exocytosis as the mechanism of release. PMID:23786442

  6. Cosmological Constraints on Bose-Einstein-Condensed Scalar Field Dark Matter

    NASA Astrophysics Data System (ADS)

    Li, B.; Rindler-Daller, T.; Shapiro, P. R.

    2013-10-01

    We focus on the hypothesis that the darkmatter is comprised of ultralight bosons that form a Bose-Einstein Condensate (BEC), described by a complex scalar field. We calculate the evolution of the Friedmann-Robertson-Walker (FRW) universe in the presence of the BEC scalar field dark matter (SFDM).We find that, while WIMP CDM is non-relativistic at all times after it decouples, the equation of state of SFDM is found to be relativistic at early times, evolving from stiff (p¯ =r¯ ) to radiation-like (p¯ =r¯/3), before it becomes non-relativistic and CDM-like at late times (p¯ = 0. The stiff phase is a distinctive feature of our model. The timing of the transitions between these phases and regimes is shown to yield fundamental constraints on the SFDM model parameters, particle mass m and self-interaction coupling strength l . We show that SFDM is compatible with observations of the evolving background universe, by deriving the range of particle parameters required to match observations of the cosmic microwave background (CMB) and the abundances of the light elements produced by Big Bang nucleosynthesis (BBN), including Neff, the effective number of neutrino species, and the epoch of matter-radiation equality zeq. This yields m ≥ 2.4× 10-21eV/c2 and 9.5×10-19eV-1cm3 ≤l /(mc2)2 ≤ 4×10-17eV-1cm3. Indeed, our model can accommodate current observations in which Neff is higher at the BBN epoch than at zeq, probed by the CMB, which is otherwise unexplained by the standard CDM model involving WIMPs.

  7. Morphological and physicochemical properties of dip-coated poly {(2,5-diyl pyrrole) [4-nitrobenzylidène]} (PPNB) thin films: towards photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Mouchaal, Younes; Gherrass, Hamou; Bendoukha Reguig, Abdelkarim; Hachemaoui, Aïcha; Yahiaoui, Ahmed; Makha, Mohamed; Khelil, Abdelbacet; Bernede, Jean-Christian

    2015-02-01

    A new material: conjugated poly {(2,5-diyl pyrrole) [4-nitrobenzylidène]}, that we called (PPNB), has been synthesized and characterized. The cyclic voltammetry has been used in order to estimate first oxidation (Ep) and reduction (En) potentials of our polymer. These values have been assigned, respectively, to the position of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) and determination of the energy band gap which have been estimated to be 6.16, 3.89 and 2.27 eV respectively. Energy levels values of the HOMO and LUMO of the PPNB polymeric donor material were evaluated and the results are compatible with an electron transfer to C60 within an eventual junction, such values show that PPNB could be probed for applications in organic solar cells as donor material. PPNB Thin films have been deposited by dip-coating technique from Dichloromethane solvent with different polymer concentrations, and a dipping speed of 3.0 cm/min. For morphological characterization of the films scanning electron microscopy (SEM) was carried out. The samples, when observed by SEM, reveals that the films deposited are less dense, uniform. Cross-sectional SEM micrographs PPNB films show that thickness of the layers is homogeneous and has value of 35-40 nm. Optical characteristics of the polymer thin films were studied using UV-vis spectroscopy; absorption of wide range of wavelengths from 350 to 700 nm was observed. The optical band gap energy ranges between 1.9 eV and 1.94 eV. Based on these analyzes we realized heterojunction organic solar cells with the structure: ITO/Au/PPNB/C60/BCP/Al, the cells had a photovoltaique effect after J-V measuring, however the efficiency of photo generation under AM1.5 illumination was weak (about 0.02%) and needs to be improved.

  8. 42% 500X Bi-Facial Growth Concentrator Cells

    NASA Astrophysics Data System (ADS)

    Wojtczuk, S.; Chiu, P.; Zhang, X.; Pulver, D.; Harris, C.; Siskavich, B.

    2011-12-01

    Data are presented from three-junction concentrator photovoltaic cells using a new cell architecture (1.9 eV InGaP top cell lattice-matched to a 1.42 eV GaAs middle cells on one side of a infrared-transparent GaAs wafer with a lattice-mismatched 0.95 eV InGaAs bottom cell grown isolated on the wafer backside). The cell uses a new epitaxial bifacial growth (BFG) technique. The impetus is to replace the 0.67 eV Ge bottom cell in the standard three junction InGaP/GaAs/Ge tandems with a higher bandgap 0.95 eV InGaAs cell that boosts the bottom cell voltage by about 40% while maintaining a simple high-yield cell process without use of complex large area epitaxial liftoff or wafer bonding steps used to make similar cell stacks. Efficiency was independently-verified by NREL for a 1 cm×1 cm cell (42.3% at 406 suns, with Voc 3.452V, 87.1% FF and 1xJsc of 14.07 mA/cm2, at 25 °C AM1.5D, 100 mW/cm2), which was the world record at the time of the CPV-7 conference. No degradation was seen during concentrated solar operation after a 2000 hr 165C burn-in and PbSn solder tests. Average efficiency of 1 cm2 cells designed for 500 suns at 1018 suns was 40.5% (Spire test, 25 °C, spectrally corrected flash simulator). Measured efficiency temperature coefficient for gen2 cells is -0.06%/°C, similar to InGaP/GaAs/Ge tandems.

  9. Microscopic hole-transfer efficiency in organic thin-film transistors studied with charge-modulation spectroscopy

    NASA Astrophysics Data System (ADS)

    Miyata, Kiyoshi; Tanaka, Shunsuke; Ishino, Yuuta; Watanabe, Kazuya; Uemura, Takafumi; Takeya, Jun; Sugimoto, Toshiki; Matsumoto, Yoshiyasu

    2015-05-01

    While the microscopic transfer properties of carriers are of primary importance for carrier transport of organic semiconductors, the mesoscopic features including the morphologies of grains and the structure of grain boundaries limit the overall carrier transport particularly in polycrystalline organic thin films. Thus the conventional evaluation methods of carrier mobility that rely on macroscopic properties such as I -V curves of devices are not capable to determine carrier transfer probability at the molecular level. Here, we present a method for evaluating the relative strengths of transfer integrals using charge-modulation spectroscopy on thin-film transistors of dinaphtho[2 ,3 -b :2',3'-f ]thieno[3 ,2 -b ]thiophene (DNTT) and its alkylated derivatives (Cn-DNTT, n =8 , 10, and 12). The band edges of absorption spectra of holes at around 1.9 eV show bathochromic shifts with increasing length of alkyl chains introduced at both ends of a DNTT chromophore. Applying a two-dimensional model with Holstein-type Hamiltonians to electronic transitions of holes, we have been able to simulate the features of the absorption band edges observed. The simulations indicate that the bathochromic shifts are due to an increase in the transfer integrals of holes with increasing length of alkyl chains. Thus this analysis confirmed that the subtle changes in the mutual orientations between adjacent DNTT chromophores induced by alkyl chains enhance the microscopic hole transfer rate. Although this fastener effect has been suggested by hole mobility measurements by I -V curves, the spectral analysis in this study gives clear evidence of this effect at the molecular level.

  10. Photoelectrochemical salt water splitting using ternary silver-tin-selenide photoelectrodes

    NASA Astrophysics Data System (ADS)

    Cheng, Kong-Wei; Wu, Yu-Hsiang; Chiu, Ting-Hsuan

    2016-03-01

    Ternary AgSnSe2 and Ag8SnSe6 semiconductor photoelectrodes are prepared on various substrates via the selenization of thermally evaporation of silver-tin metal precursors. The structural, optical and electrical properties of ternary AgSnSe2 and Ag8SnSe6 samples are investigated as a function of the [Ag]/[Ag + Sn] molar ratio in the metal precursors. X-ray diffraction patterns of samples show that the phases of samples change from cubic AgSnSe2 to cubic Ag8SnSe6 phase at a selenization temperature of 410 °C when the molar ratio of [Ag]/[Ag + Sn] in silver-tin metal precursors increase from 0.51 to 0.68. The images obtained from a field-emission scanning electron microscopy show that the surface microstructures of samples change from plate-like microstructures with some pinholes to polygonal microstructures with increasing [Ag]/[Ag + Sn] molar ratios in samples. The energy bang gaps, carrier concentrations and mobilities of the samples are in the ranges of 0.86-1.19 eV, 1.27 × 1011-2.39 × 1012 cm-3 and 238-655 cm2 V-1 s-1, respectively. The highest photo-enhanced current densities of the samples in aqueous Na2S + K2SO3 and NaCl solutions are 3.34 and 0.61 mA cm-2 at an applied voltage of 0 and + 0.4 V vs. an Ag/AgCl electrode under 100 mW cm-2 light illumination from a Xe lamp source, respectively.

  11. The Potential of Spaced-based High-Energy Neutrino Measurements via the Airshower Cherenkov Signal

    NASA Technical Reports Server (NTRS)

    Krizmanic, John F.; Mitchell, John W.

    2011-01-01

    Future space-based experiments, such as (Orbiting Wide-angle Light Collectors (OWL) and JEM-EUSO, view large atmospheric and terrestrial neutrino targets. With energy thresholds slightly above 10(exp 19) eV for observing airshowers via air fluorescence, the potential for observing the cosmogenic neutrino flux associated with the GZK effect is limited. However, the forward Cherenkov signal associated with the airshower can be observed at much lower energies. A simulation was developed to determine the Cherenkov signal strength and spatial extent at low-Earth orbit for upward-moving airshowers. A model of tau neutrino interactions in the Earth was employed to determine the event rate of interactions that yielded a tau lepton which would induce an upward-moving airshower observable by a space-based instrument. The effect of neutrino attenuation by the Earth forces the viewing of the Earth's limb to observe the vT-induced Cherenkov airshower signal at above the OWL Cherenkov energy threshold of approximately 10(exp 16.5) eV for limb-viewed events. Furthermore, the neutrino attenuation limits the effective terrestrial neutrino target area to approximately 3 x 10(exp 5) square km at 10(exp 17) eV, for an orbit of 1000 km and an instrumental full Field-of-View of 45 deg. This translates into an observable cosmogenic neutrino event rate of approx. l/year based upon two different models of the cosmogenic neutrino flux, assuming neutrino oscillations and a 10% duty cycle for observation.

  12. In Vitro Drug Sensitivity Tests to Predict Molecular Target Drug Responses in Surgically Resected Lung Cancer

    PubMed Central

    Miyazaki, Ryohei; Anayama, Takashi; Hirohashi, Kentaro; Okada, Hironobu; Kume, Motohiko; Orihashi, Kazumasa

    2016-01-01

    Background Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and anaplastic lymphoma kinase (ALK) inhibitors have dramatically changed the strategy of medical treatment of lung cancer. Patients should be screened for the presence of the EGFR mutation or echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion gene prior to chemotherapy to predict their clinical response. The succinate dehydrogenase inhibition (SDI) test and collagen gel droplet embedded culture drug sensitivity test (CD-DST) are established in vitro drug sensitivity tests, which may predict the sensitivity of patients to cytotoxic anticancer drugs. We applied in vitro drug sensitivity tests for cyclopedic prediction of clinical responses to different molecular targeting drugs. Methods The growth inhibitory effects of erlotinib and crizotinib were confirmed for lung cancer cell lines using SDI and CD-DST. The sensitivity of 35 cases of surgically resected lung cancer to erlotinib was examined using SDI or CD-DST, and compared with EGFR mutation status. Results HCC827 (Exon19: E746-A750 del) and H3122 (EML4-ALK) cells were inhibited by lower concentrations of erlotinib and crizotinib, respectively than A549, H460, and H1975 (L858R+T790M) cells were. The viability of the surgically resected lung cancer was 60.0 ± 9.8 and 86.8 ± 13.9% in EGFR-mutants vs. wild types in the SDI (p = 0.0003). The cell viability was 33.5 ± 21.2 and 79.0 ± 18.6% in EGFR mutants vs. wild-type cases (p = 0.026) in CD-DST. Conclusions In vitro drug sensitivity evaluated by either SDI or CD-DST correlated with EGFR gene status. Therefore, SDI and CD-DST may be useful predictors of potential clinical responses to the molecular anticancer drugs, cyclopedically. PMID:27070423

  13. Thickness Effect on Properties of Sprayed In2S3 Films for Photovoltaic Applications

    NASA Astrophysics Data System (ADS)

    Bouguila, N.; Kraini, M.; Halidou, I.; Lacaze, E.; Bouchriha, H.; Bouzouita, H.

    2016-01-01

    Indium sulfide (In2S3) films have been deposited on soda-lime glass substrates using a spray technique (CSP). Indium chloride and thiourea were used as precursors at a molar ratio of S:In = 2. The substrate temperature was fixed at 340°C. The effect of film thickness on the structural, morphological and optical properties of the as-deposited films has been studied. These films were characterized by x-ray diffraction, scanning electron microscopy (SEM), atomic force microscopy (AFM) and optical absorption spectroscopy. As-prepared samples were polycrystalline with a cubic structure and (400) as preferential orientation. Their grain size increased from 35 nm to 41 nm with increasing thickness whereas the dislocation density and microstrain of the films decreased with the increase of thickness. Both SEM and AFM images showed that the films were homogenous with an increase of the surface roughness with the increase of thickness. The optical transmittance of the films decreased from 80% to 20% in the visible and infrared regions when the thickness was increased from 0.78 μm to 6.09 μm. The optical band gap E g was found to be in the range of 2.75-2.19 eV and showed a decrease with film thickness. Based on the measured optical constants (n and k), a Wemple-Didomenico model was used to determine the values of single oscillator energy ( E 0), dispersion energy ( E d), optical band gap ( E g) and high frequency dielectric constant ( \\varepsilon_{∞} ). In addition, these films exhibited n-type conductivity and were highly resistive. These results confirm that In2S3 thin films are a promising alternative as a buffer-layer material for CuInGa(S,Se)2-based solar cells.

  14. Bitter, sweet and umami taste receptors and downstream signaling effectors: Expression in embryonic and growing chicken gastrointestinal tract.

    PubMed

    Cheled-Shoval, Shira L; Druyan, Shelly; Uni, Zehava

    2015-08-01

    Taste perception is a crucial biological mechanism affecting food and water choices and consumption in the animal kingdom. Bitter taste perception is mediated by a G-protein-coupled receptor (GPCR) family-the taste 2 receptors (T2R)-and their downstream proteins, whereas sweet and umami tastes are mediated by the GPCR family -taste 1 receptors (T1R) and their downstream proteins. Taste receptors and their downstream proteins have been identified in extra-gustatory tissues in mammals, such as the lungs and gastrointestinal tract (GIT), and their GIT activation has been linked with different metabolic and endocrinic pathways in the GIT. The chicken genome contains three bitter taste receptors termed ggTas2r1, ggTas2r2, and ggTas2r7, and the sweet/umami receptors ggTas1r1 and ggTas1r3, but it lacks the sweet receptor ggTas1r2. The aim of this study was to identify and determine the expression of genes related to taste perception in the chicken GIT, both at the embryonic stage and in growing chickens. The results of this study demonstrate for the first time, using real-time PCR, expression of the chicken taste receptor genes ggTas2r1, ggTas2r2, ggTas2r7, ggTas1r1, and ggTas1r3 and of their downstream protein-encoding genes TRPM5, α-gustducin, and PLCβ2 in both gustatory tissues-the palate and tongue, and extra-gustatory tissues-the proventriculus, duodenum, jejunum, ileum, cecum, and colon of embryonic day 19 (E19) and growing (21 d old) chickens. Expression of these genes suggests the involvement of taste pathways for sensing carbohydrates, amino acids and bitter compounds in the chicken GIT. PMID:26049797

  15. Quantum Chemical Benchmark Studies of the Electronic Properties of the Green Fluorescent Protein Chromophore. 1. Electronically Excited and Ionized States of the Anionic Chromophore in the Gas Phase.

    PubMed

    Epifanovsky, Evgeny; Polyakov, Igor; Grigorenko, Bella; Nemukhin, Alexander; Krylov, Anna I

    2009-07-14

    We present the results of quantum chemical calculations of the electronic properties of the anionic form of the green fluorescent protein chromophore in the gas phase. The vertical detachment energy of the chromophore is found to be 2.4-2.5 eV, which is below the strongly absorbing ππ* state at 2.6 eV. The vertical excitation of the lowest triplet state is around 1.9 eV, which is below the photodetachment continuum. Thus, the lowest bright singlet state is a resonance state embedded in the photodetachment continuum, whereas the lowest triplet state is a regular bound state. Based on our estimation of the vertical detachment energy, we attribute a minor feature in the action spectrum as due to the photodetachment transition. The benchmark results for the bright ππ* state demonstrated that the scaled opposite-spin method yields vertical excitation within 0.1 eV (20 nm) from the experimental maximum at 2.59 eV (479 nm). We also report estimations of the vertical excitation energy obtained with the equation-of-motion coupled cluster with the singles and doubles method, a multireference perturbation theory corrected approach MRMP2 as well as the time-dependent density functional theory with range-separated functionals. Expanding the basis set with diffuse functions lowers the ππ* vertical excitation energy by 0.1 eV at the same time revealing a continuum of "ionized" states, which embeds the bright ππ* transition. PMID:26610014

  16. Deposition of nanostructured photocatalytic zinc ferrite films using solution precursor plasma spraying

    SciTech Connect

    Dom, Rekha; Sivakumar, G.; Hebalkar, Neha Y.; Joshi, Shrikant V.; Borse, Pramod H.

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Highly economic solution precursor route capable of producing films/coating even for mass scale production. Black-Right-Pointing-Pointer Pure spinel phase ZnFe{sub 2}O{sub 4} porous, immobilized films deposited in single step. Black-Right-Pointing-Pointer Parameter optimization yields access to nanostructuring in SPPS method. Black-Right-Pointing-Pointer The ecofriendly immobilized ferrite films were active under solar radiation. Black-Right-Pointing-Pointer Such magnetic system display advantage w.r.t. recyclability after photocatalyst extraction. -- Abstract: Deposition of pure spinel phase, photocatalytic zinc ferrite films on SS-304 substrates by solution precursor plasma spraying (SPPS) has been demonstrated for the first time. Deposition parameters such as precursor solution pH, concentration, film thickness, plasma power and gun-substrate distance were found to control physico-chemical properties of the film, with respect to their crystallinity, phase purity, and morphology. Alkaline precursor conditions (7 < pH {<=} 10) were found to favor oxide film formation. The nanostructured films produced under optimized conditions, with 500 mM solution at pH {approx} 8.0, yielded pure cubic phase ZnFe{sub 2}O{sub 4} film. Very high/low precursor concentrations yielded mixed phase, less adherent, and highly inhomogeneous thin films. Desired spinel phase was achieved in as-deposited condition under appropriately controlled spray conditions and exhibited a band gap of {approx}1.9 eV. The highly porous nature of the films favored its photocatalytic performance as indicated by methylene blue de-coloration under solar radiation. These immobilized films display good potential for visible light photocatalytic applications.

  17. Efficiency of generation of optical centers in KS-4V and KU-1 quartz glasses at neutron and gamma irradiation

    NASA Astrophysics Data System (ADS)

    Islamov, A. Kh.; Salikhbaev, U. S.; Ibragimova, E. M.; Nuritdinov, I.; Fayzullaev, B. S.; Vukolov, K. Yu.; Orlovskiy, I.

    2013-11-01

    Pure quartz glasses of KS-4V and KU-1 types are candidates for optical plasma diagnostic system in ITER. The purpose of experiment was to study the efficiency of defect production in these glasses under irradiation with 60Со γ-quanta (5.7 Gy/s) dose range of 102-107 Gy and the fission reactor neutrons in the fluency range of 1020-1023 n/m2 and gammas simulating the plasma influence. In KU-1 (1000 ppm OH) the accumulation kinetics of E‧-(5.75 eV) and NBO-(1.9 eV) centers at γ-doses⩾5×105 Gy and neutron fluencies <1021 n/m2 is faster, than that in KS-4V glasses (<0.1 ppm OH) that is caused by rupture of hydrogen bonds. At fluencies >1021 n/m2 the NBO accumulation kinetics is slower in KU-1 than in KS-4B, because highly mobile hydrogen atoms access to the generated NBO centers. In KS-4V irradiated to γ-doses102-5 × 103 Gy a new unstable absorption band at 1.8 eV was found, which is caused by the glass synthesis conditions and alkali metal impurities. The transparency at 3.5-6.2 eV at fluencies 1020-5 × 1021 n/m2 is higher in KS-4V than KU-1. However at fluencies >1021 n/m2 in KS-4V the photoluminescence band at 2.7 eV is more intensive and distorts a diagnosed signal. The transparency in 3.5-1.2 eV at fluencies >1021 n/m2 is higher in KU-1 than KS-4V.

  18. Genetic variation at the delta-sarcoglycan (SGCD) locus elevates heritable sympathetic nerve activity in human twin pairs.

    PubMed

    Hightower, C Makena; Zhang, Kuixing; Miramontes-González, José P; Rao, Fangwen; Wei, Zhiyun; Schork, Andrew J; Nievergelt, Caroline M; Biswas, Nilima; Mahata, Manjula; Elkelis, Nina; Taupenot, Laurent; Stridsberg, Mats; Ziegler, Michael G; O'Connor, Daniel T

    2013-12-01

    The Syrian Cardiomyopathic Hamster (BIO-14.6/53.58 strains) model of cardiac failure, resulting from naturally occurring deletion at the SGCD (delta-sarcoglycan) locus, displays widespread disturbances in catecholamine metabolism. Rare Mendelian myopathy disorders of human SGCD occur, although common naturally occurring SGCD genetic variation has not been evaluated for effects on human norepinephrine (NE) secretion. This study investigated the effect of SGCD genetic variation on control of NE secretion in healthy twin pairs. Genetic associations profiled SNPs across the SGCD locus. Trait heritability (h(2)) and genetic covariance (pleiotropy; shared h(2)) were evaluated. Sympathochromaffin exocytosis in vivo was probed in plasma by both catecholamines and Chromogranin B (CHGB). Plasma NE is substantially heritable (p = 3.19E-16, at 65.2 ± 5.0% of trait variance), sharing significant (p < 0.05) genetic determination with circulating and urinary catecholamines, CHGB, eGFR, and several cardio-metabolic traits. Participants with higher pNE showed significant (p < 0.05) differences in several traits, including increased BP and hypertension risk factors. Peak SGCD variant rs1835919 predicted elevated systemic vascular compliance, without changes in specifically myocardial traits. We used a chimeric-regulated secretory pathway photoprotein (CHGA-EAP) to evaluate the effect of SGCD on the exocytotic pathway in transfected PC12 cells; in transfected cells, expression of SGCD augmented CHGA trafficking into the exocytotic regulated secretory pathway. Thus, our investigation determined human NE secretion to be a highly heritable trait, influenced by common genetic variation within the SGCD locus. Circulating NE aggregates with BP and hypertension risk factors. In addition, coordinate NE and CHGB elevation by rs1835919 implicates exocytosis as the mechanism of release. PMID:23786442

  19. Ali Observatory in Tibet: a unique northern site for future CMB ground-based observations

    NASA Astrophysics Data System (ADS)

    Su, Meng

    2015-08-01

    Ground-based CMB observations have been performed at the South Pole and the Atacama desert in Chile. However, a significant fraction of the sky can not be observed from just these two sites. For a full sky coverage from the ground in the future, a northern site for CMB observation, in particular CMB polarization, is required. Besides the long-thought site in Greenland, the high altitude Tibet plateau provides another opportunity. I will describe the Ali Observatory in Tibet, located at N32°19', E80°01', as a potential site for ground-based CMB observations. The new site is located on almost 5100m mountain, near Gar town, where is an excellent site for both infrared and submillimeter observations. Study with the long-term database of ground weather stations and archival satellite data has been performed. The site has enough relative height on the plateau and is accessible by car. The Shiquanhe town is 40 mins away by driving, and a recently opened airport with 40 mins driving, the site also has road excess, electricity, and optical fiber with fast internet. Preliminary measurement of the Precipitable Water Vapor is ~one quarter less than 0.5mm per year and the long term monitoring is under development. In addition, surrounding higher sites are also available and could be further developed if necessary. Ali provides unique northern sky coverage and together with the South Pole and the Atacama desert, future CMB observations will be able to cover the full sky from ground.

  20. Calendars in the Gregorian Spirit

    NASA Astrophysics Data System (ADS)

    Lichtenberg, Heiner; Richter, Peter H.

    The Gregorian Calendar is an adaptable cyclic, lunisolar time-reckoning system [1]. It assumes the following equations: atrop &=& 1461/4 - s/(100 × P1) quad days msyn &=& atrop / (235/19 + e/(3000 × P2))quad day s for the average tropical year atrop and the average synodical month msyn, respectively [2]. s is the number of leap years reverting to common years at the secular boundaries of the period P1, measured in centuries. e is the number of (net) adjustments of the epact at the secular boundaries of the period P2, measured in centuries. The particular form of this rational approximation characterizes the Gregorian spirit; the standard integers s = 3, P1 = 4, e = -43, P2 = 100 are open for adjustment. Truncated continued fraction expansions should be used to successively improve the accuracy. For atrop = 365.2422 d and msyn = 29.530588 d, we find that s = 3, P1 = 4, e = -19, P2 = 44 is slightly better than the standard values. Its fundamental equation 2,508,000 atrop = 31,019,639 msyn = 916,028,190 d defines a period about half as long as for the usual Gregorian calendar, 5,700,000 atrop = 70,499,183 msyn = 2,081,882,250 d [3]. [1] Clavius, Chr., Rom. Cal. Explic., Rome 1603, (= Op. math., tom. V, Mainz 1612). [2] Lichtenberg, H., The Gregorian Calendar: An Adaptable Cyclic Lunisolar Time-reckoning System for the Millennia, Hum. Welf. Stud., vol. 2 (1999), pp. 137 - 148. [3] Explan. Suppl. Astron. Almanac, ed. P. K. Seidelmann, Mill Valley, Ca.,

  1. Naphthalene bisimides asymmetrically and symmetrically N-substituted with triarylamine--comparison of spectroscopic, electrochemical, electronic and self-assembly properties.

    PubMed

    Rybakiewicz, Renata; Zapala, Joanna; Djurado, David; Nowakowski, Robert; Toman, Petr; Pfleger, Jiri; Verilhac, Jean-Marie; Zagorska, Malgorzata; Pron, Adam

    2013-02-01

    Two semiconducting naphthalene bisimides were comparatively studied: NBI-(TAA)(2), symmetrically N-substituted with triaryl amine and asymmetric NBI-TAA-Oc with triaryl amine and octyl N-substituents. Both compounds show very similar spectroscopic and redox properties but differ in their supramolecular organization. As evidenced by STM, in monolayers on HOPG they form ordered 2D structures, however of different packing patterns. NBI-(TAA)(2) does not form ordered 3D structures, yielding amorphous thin films whereas films of NBI-TAA-Oc are highly crystalline. DFT calculations predict the ionization potential (IP) of 5.22 eV and 5.18 eV for NBI-TAA-Oc and NBI-(TAA)(2), respectively, as well as the electron affinity values (EA) of -3.25 eV and -3.22 eV. These results are consistent with the cyclic voltammetry data which yield similar values of IP (5.20 eV and 5.19 eV) and somehow different values of EA (-3.80 eV and -3.83 eV). As judged from these data, both semiconductors should exhibit ambipolar behavior. Indeed, NBI-TAA-Oc is ambipolar, showing hole and electron mobilities of 4.5 × 10(-5) cm(2)/(V s) and of 2.6 × 10(-4) cm(2)/(V s), respectively, in the field effect transistor configuration. NBI-(TAA)(2) is not ambipolar and yields field effect only in the p-channel configuration. This different behavior is rationalized on the basis of structural factors. PMID:23243662

  2. Evidence for strong f -d hybridization in the intermetallic ferromagnet CePdIn2

    NASA Astrophysics Data System (ADS)

    Carleschi, E.; Doyle, B. P.; Snyman, J. L.; Magnano, E.; Nappini, S.; Pis, I.; Bondino, F.; Peratheepan, P.; Strydom, A. M.

    2015-12-01

    We have investigated the contribution of Ce 4 f states to the electronic structure of the intermetallic ferromagnet CePdIn2 by means of x-ray absorption spectroscopy and resonant and nonresonant photoemission spectroscopy. The line shape of the Ce M5 ,4 absorption edge reveals the localized nature of the 4 f states, and is consistent with a predominantly 3+ ionic state for Ce ions. Fitting of the Ce 3 d core level gives a Ce 4 f occupation number at room temperature of 0.92, which is in good agreement with the Ce effective magnetic moment of 2.20 μB (corresponding to ˜87 % of the free-electron moment) as calculated from the inverse magnetic susceptibility. Moreover, the hybridization strength between 4 f and conduction electrons is found to be ˜180 meV, revealing that CePdIn2 is a strongly hybridized system. This is consistent with the results from the analysis of the resonant valence band photoemission measurements at both the N5 ,4 and the M5 edges, showing that the Ce 4 f states are composed of the features predicted by the single-impurity Anderson model, i.e., a broad 4 f0 peak centered at 1.9 eV and two 4 f1 spin-orbit states much closer to the Fermi level. The same spectra also show that the Ce 4 f resonant spectral weight extends over a wide binding energy range, overlapping with that presumably occupied by the Pd 4 d ligand states. This energy overlap is interpreted as a signature of the strong hybridization governing the system, which could possibly favor the emergence of long-range ferromagnetism through the indirect exchange between localized 4 f states mediated by highly dispersive d electrons.

  3. First results on neutrinoless double beta decay of Te-130 with the calorimetric cuoricino experiment

    SciTech Connect

    Arnaboldi, C.; Artusa, D.R.; Avignone, F.T.; Balata, M.; Bandac, I.; Barucci, M.; Beeman, J.W.; Brofferio, C.; Bucci, C.; Capelli, S.; Capozzi, F.; Carbone, L.; Cebrian, S.; Cremonesi, O.; Creswick, R.J.; de Waard, A.; Farach, H.A.; Fascilla, A.; Fiorini, E.; Frossati, G.; Giuliani, A.; Gorla, P.; Haller, E.E.; McDonald, R.J.; Morales, A.; Norman, E.B.; Nucciotti, A.; Olivieri, E.; Palmieri, E.; Pasca, E.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Pobes, C.; Previtali, E.; Pyle, M.; Risegari, L.; Rosenfeld, C.; Sangiorgio, S.; Sisti, M.; Smith, A.R.; Torres, L.; Ventura, G.

    2003-12-04

    The first results are reported on the limit for neutrinoless double decay of {sup 130}Te obtained with the new bolometric experiment CUORICINO. The set-up consists of 44 cubic crystals of natural TeO{sub 2}, 5 cm on the side and 18 crystals of 3 x 3 x 6 cm{sup 3}. Four of these latter crystals are made with isotopically enriched materials: two in {sup 128}Te and two others in {sup 130}Te . With a sensitive mass of {approx}40 kg, our array is by far the most massive running cryogenic detector to search for rare events. The array is operated at a temperature of {approx}10 mK in a dilution refrigerator under a heavy shield in the Gran Sasso Underground Laboratory at a depth of about 3500 m.w.e. The counting rate in the region of neutrinoless double beta decay is {approx}0.2 counts keV{sup -1} kg{sup -1} year{sup -1}, among the lowest in this type of experiment. No evidence for neutrinoless double beta decay is found with the present statistics obtained in about three months with a live time of 72%. The corresponding lower limit for the lifetime of this process is of 5.5 x 10{sup 23} years at 90% C.L. The corresponding limit for the effective neutrino mass ranges between 0.37 to 1.9 eV depending on the theoretically calculated nuclear matrix elements used. This constraint is the most restrictive one except those obtained with Ge diodes, and is comparable to them.

  4. A functional variant that affects exon-skipping and protein expression of SP140 as genetic mechanism predisposing to multiple sclerosis.

    PubMed

    Matesanz, Fuencisla; Potenciano, Victor; Fedetz, Maria; Ramos-Mozo, Priscila; Abad-Grau, María del Mar; Karaky, Mohamad; Barrionuevo, Cristina; Izquierdo, Guillermo; Ruiz-Peña, Juan Luis; García-Sánchez, María Isabel; Lucas, Miguel; Fernández, Óscar; Leyva, Laura; Otaegui, David; Muñoz-Culla, Maider; Olascoaga, Javier; Vandenbroeck, Koen; Alloza, Iraide; Astobiza, Ianire; Antigüedad, Alfredo; Villar, Luisa María; Álvarez-Cermeño, José Carlos; Malhotra, Sunny; Comabella, Manuel; Montalban, Xavier; Saiz, Albert; Blanco, Yolanda; Arroyo, Rafael; Varadé, Jezabel; Urcelay, Elena; Alcina, Antonio

    2015-10-01

    Several variants in strong linkage disequilibrium (LD) at the SP140 locus have been associated with multiple sclerosis (MS), Crohn's disease (CD) and chronic lymphocytic leukemia (CLL). To determine the causal polymorphism, we have integrated high-density data sets of expression quantitative trait loci (eQTL), using GEUVADIS RNA sequences and 1000 Genomes genotypes, with MS-risk variants of the high-density Immunochip array performed by the International Multiple Sclerosis Genetic Consortium (IMSGC). The variants most associated with MS were also correlated with a decreased expression of the full-length RNA isoform of SP140 and an increase of an isoform lacking exon 7. By exon splicing assay, we have demonstrated that the rs28445040 variant was the causal factor for skipping of exon 7. Western blots of peripheral blood mononuclear cells from MS patients showed a significant allele-dependent reduction of the SP140 protein expression. To confirm the association of this functional variant with MS and to compare it with the best-associated variant previously reported by GWAS (rs10201872), a case-control study including 4384 MS patients and 3197 controls was performed. Both variants, in strong LD (r(2) = 0.93), were found similarly associated with MS [P-values, odds ratios: 1.9E-9, OR = 1.35 (1.22-1.49) and 4.9E-10, OR = 1.37 (1.24-1.51), respectively]. In conclusion, our data uncover the causal variant for the SP140 locus and the molecular mechanism associated with MS risk. In addition, this study and others previously reported strongly suggest that this functional variant may be shared with other immune-mediated diseases as CD and CLL. PMID:26152201

  5. Ferromagnetism and semiconducting of boron nanowires

    PubMed Central

    2012-01-01

    More recently, motivated by extensively technical applications of carbon nanostructures, there is a growing interest in exploring novel non-carbon nanostructures. As the nearest neighbor of carbon in the periodic table, boron has exceptional properties of low volatility and high melting point and is stronger than steel, harder than corundum, and lighter than aluminum. Boron nanostructures thus are expected to have broad applications in various circumstances. In this contribution, we have performed a systematical study of the stability and electronic and magnetic properties of boron nanowires using the spin-polarized density functional calculations. Our calculations have revealed that there are six stable configurations of boron nanowires obtained by growing along different base vectors from the unit cell of the bulk α-rhombohedral boron (α-B) and β-rhombohedral boron (β-B). Well known, the boron bulk is usually metallic without magnetism. However, theoretical results about the magnetic and electronic properties showed that, whether for the α-B-based or the β-B-based nanowires, their magnetism is dependent on the growing direction. When the boron nanowires grow along the base vector [001], they exhibit ferromagnetism and have the magnetic moments of 1.98 and 2.62 μB, respectively, for the α-c [001] and β-c [001] directions. Electronically, when the boron nanowire grows along the α-c [001] direction, it shows semiconducting and has the direct bandgap of 0.19 eV. These results showed that boron nanowires possess the unique direction dependence of the magnetic and semiconducting behaviors, which are distinctly different from that of the bulk boron. Therefore, these theoretical findings would bring boron nanowires to have many promising applications that are novel for the boron bulk. PMID:23244063

  6. Whole-Genome Analyses of Enterococcus faecium Isolates with Diverse Daptomycin MICs

    PubMed Central

    Diaz, Lorena; Tran, Truc T.; Munita, Jose M.; Miller, William R.; Rincon, Sandra; Carvajal, Lina P.; Wollam, Aye; Reyes, Jinnethe; Panesso, Diana; Rojas, Natalia L.; Shamoo, Yousif; Murray, Barbara E.; Weinstock, George M.

    2014-01-01

    Daptomycin (DAP) is a lipopeptide antibiotic frequently used as a “last-resort” antibiotic against vancomycin-resistant Enterococcus faecium (VRE). However, an important limitation for DAP therapy against VRE is the emergence of resistance during therapy. Mutations in regulatory systems involved in cell envelope homeostasis are postulated to be important mediators of DAP resistance in E. faecium. Thus, in order to gain insights into the genetic bases of DAP resistance in E. faecium, we investigated the presence of changes in 43 predicted proteins previously associated with DAP resistance in enterococci and staphylococci using the genomes of 19 E. faecium with different DAP MICs (range, 3 to 48 μg/ml). Bodipy-DAP (BDP-DAP) binding to the cell membrane assays and time-kill curves (DAP alone and with ampicillin) were performed. Genetic changes involving two major pathways were identified: (i) LiaFSR, a regulatory system associated with the cell envelope stress response, and (ii) YycFGHIJ, a system involved in the regulation of cell wall homeostasis. Thr120→Ala and Trp73→Cys substitutions in LiaS and LiaR, respectively, were the most common changes identified. DAP bactericidal activity was abolished in the presence of liaFSR or yycFGHIJ mutations regardless of the DAP MIC and was restored in the presence of ampicillin, but only in representatives of the LiaFSR pathway. Reduced binding of BDP-DAP to the cell surface was the predominant finding correlating with resistance in isolates with DAP MICs above the susceptibility breakpoint. Our findings suggest that genotypic information may be crucial to predict response to DAP plus β-lactam combinations and continue to question the DAP breakpoint of 4 μg/ml. PMID:24867964

  7. [Atypical BCR-ABL transcripts in patients with chronic myeloid leukemia--the scheme for the diagnosis and monitoring of minimal residual disease].

    PubMed

    Link-Lenczowska, Dorota; Sacha, Tomasz; Zawada, Magdalena; Czekalska, Sylwia; Florek, Izabela; Skotnicki, Aleksander B

    2014-01-01

    More than 95% of patients with detected translocation t(9;22), is characterized by the fusion between exons e13 or e14 of BCR gene, which are located in major breakpoint cluster region (M-bcr) and exon a2 of ABL gene. These fusions are described as b2a2 (e13a2) and b3a2 (e14a2). Other fusions of exons e1, e6, e8, e12, e19, e20 of BCR gene with exons a2 or a3 of ABL gene occur very rarely and lead to formation of so called unusual fusion BCR-ABL genes. The aim of this study is to describe long-term observations of the occurrence and routine procedure in the diagnosis of atypical variants of the fusion gene BCR-ABL in a population of patients with chronic myeloid leukemia (CML). It was found that the vast majority of patients with detected BCR-ABL transcripts were b3a2 and b2a2. Other detected variants, which are described as rare were: e1a2, b2a3, b3a3, c3a2, e6a2, e6a3. At the stage of diagnosis as well as during monitoring of the effects of treatment, molecular methods which are based on polymerase chain reaction were used (multiplex RT-PCR, nested RT-PCR, RQ-PCR). Multiplex RT-PCR reaction gave possibility to detect variants of the fusion BCR-ABL gene in one reaction and was crucial in the selection of appropriate test used for further monitoring of the disease and the effectiveness of treatment. This paper proposes a scheme for dealing with the diagnosis and monitoring of minimal residual disease (MRD) in patients with CML treated with tyrosine kinase inhibitors (TKIs) in the presence of rare fusion of the BCR and ABL genes. PMID:25248240

  8. SNP-SNP interaction analysis of NF-κB signaling pathway on breast cancer survival

    PubMed Central

    Jamshidi, Maral; Fagerholm, Rainer; Khan, Sofia; Aittomäki, Kristiina; Czene, Kamila; Darabi, Hatef; Li, Jingmei; Andrulis, Irene L.; Chang-Claude, Jenny; Devilee, Peter; Fasching, Peter A.; Michailidou, Kyriaki; Bolla, Manjeet K.; Dennis, Joe; Wang, Qin; Guo, Qi; Rhenius, Valerie; Cornelissen, Sten; Rudolph, Anja; Knight, Julia A.; Loehberg, Christian R.; Burwinkel, Barbara; Marme, Frederik; Hopper, John L.; Southey, Melissa C.; Bojesen, Stig E.; Flyger, Henrik; Brenner, Hermann; Holleczek, Bernd; Margolin, Sara; Mannermaa, Arto; Kosma, Veli-Matti; Dyck, Laurien Van; Nevelsteen, Ines; Couch, Fergus J.; Olson, Janet E.; Giles, Graham G.; McLean, Catriona; Haiman, Christopher A.; Henderson, Brian E.; Winqvist, Robert; Pylkäs, Katri; Tollenaar, Rob A.E.M.; García-Closas, Montserrat; Figueroa, Jonine; Hooning, Maartje J.; Martens, John W.M.; Cox, Angela; Cross, Simon S.; Simard, Jacques; Dunning, Alison M.; Easton, Douglas F.; Pharoah, Paul D.P.; Hall, Per; Blomqvist, Carl; Schmidt, Marjanka K.; Nevanlinna, Heli

    2015-01-01

    In breast cancer, constitutive activation of NF-κB has been reported, however, the impact of genetic variation of the pathway on patient prognosis has been little studied. Furthermore, a combination of genetic variants, rather than single polymorphisms, may affect disease prognosis. Here, in an extensive dataset (n = 30,431) from the Breast Cancer Association Consortium, we investigated the association of 917 SNPs in 75 genes in the NF-κB pathway with breast cancer prognosis. We explored SNP-SNP interactions on survival using the likelihood-ratio test comparing multivariate Cox’ regression models of SNP pairs without and with an interaction term. We found two interacting pairs associating with prognosis: patients simultaneously homozygous for the rare alleles of rs5996080 and rs7973914 had worse survival (HRinteraction 6.98, 95% CI=3.3-14.4, P = 1.42E-07), and patients carrying at least one rare allele for rs17243893 and rs57890595 had better survival (HRinteraction 0.51, 95% CI=0.3-0.6, P = 2.19E-05). Based on in silico functional analyses and literature, we speculate that the rs5996080 and rs7973914 loci may affect the BAFFR and TNFR1/TNFR3 receptors and breast cancer survival, possibly by disturbing both the canonical and non-canonical NF-κB pathways or their dynamics, whereas, rs17243893-rs57890595 interaction on survival may be mediated through TRAF2-TRAIL-R4 interplay. These results warrant further validation and functional analyses. PMID:26317411

  9. Identification of rhenium donors and sulfur vacancy acceptors in layered MoS2 bulk samples

    NASA Astrophysics Data System (ADS)

    Brandão, F. D.; Ribeiro, G. M.; Vaz, P. H.; González, J. C.; Krambrock, K.

    2016-06-01

    MoS2 monolayers, a two-dimensional (2D) direct semiconductor material with an energy gap of 1.9 eV, offer many opportunities to be explored in different electronic devices. Defects often play dominant roles in the electronic and optical properties of semiconductor devices. However, little experimental information about intrinsic and extrinsic defects or impurities is available for this 2D system, and even for macroscopic 3D samples for which MoS2 shows an indirect bandgap of 1.3 eV. In this work, we evaluate the nature of impurities with unpaired spins using electron paramagnetic resonance (EPR) in different geological macroscopic samples. Regarding the fact that monolayers are mostly obtained from natural crystals, we expect that the majority of impurities found in macroscopic samples are also randomly present in MoS2 monolayers. By EPR at low temperatures, rhenium donors and sulfur vacancy acceptors are identified as the main impurities in bulk MoS2 with a corresponding donor concentration of about 108-12 defects/cm2 for MoS2 monolayer. Electrical transport experiments as a function of temperature are in good agreement with the EPR results, revealing a shallow donor state with an ionization energy of 89 meV and a concentration of 7 × 1015 cm-3, which we attribute to rhenium, as well as a second deeper donor state with ionization energy of 241 meV with high concentration of 2 × 1019 cm-3 and net acceptor concentration of 5 × 1018 cm-3 related to sulfur vacancies.

  10. Dealing with spatial heterogeneity

    NASA Astrophysics Data System (ADS)

    Marsily, Gh.; Delay, F.; Gonçalvès, J.; Renard, Ph.; Teles, V.; Violette, S.

    2005-03-01

    ès fins de barrières de perméabilité, qui ont une influence importante sur les écoulement, et, plus encore, sur le transport. Les modè les génétiques récemment apparus ont la capacité de mieux incorporer dans les modèles de faciès les observations géologiques, chose courante dans l'industrie pétrolière, mais insuffisamment développée en hydrogéologie. On conclut que les travaux de recherche ultérieurs devraient s'attacher à développer les modèles de faciès, à les comparer entre eux, et à mettre au point de nouvelles méthodes d'essais in situ, comprenant les méthodes géophysiques, capables de reconnaître la géométrie et les propriétés des faciès. La constitution d'un catalogue mondial de la géométrie et des propriétés des faciès aquifères, ainsi que des méthodes de reconnaissance utilisées pour arriver à la détermination de ces systèmes, serait d'une grande importance pratique pour les applications. La heterogeneidad se puede manejar por medio de la definición de características homogéneas equivalentes, conocidas como promediar o tratando de describir la variabilidad espacial de las características de las rocas a partir de observaciones geológicas y medidas locales. Las técnicas disponibles para estas descripciones son generalmente modelos geoestadísticos continuos o modelos de facies discontinuos como los modelos Boolean, de Indicador o de umbral de Gaussian y el modelo de cadena de Markow. Estos modelos de facies son mas adecuados para tratar la conectvidad de estratos geológicos (por ejemplo canales de alta permeabilidad enterrados o barreras de baja permeabilidad que tienen efectos importantes sobre el flujo y especialmente sobre el transporte en los acuíferos. Los modelos genéticos ofrecen nuevas formas de incorporar más geología en las descripciones de facies, un enfoque que está bien desarollado en la industria petrolera, pero insuficientemente en la hidrogeología. Se concluye que los trabajos futuros deber

  11. Dealing with spatial heterogeneity

    NASA Astrophysics Data System (ADS)

    Marsily, Gh.; Delay, F.; Gonçalvès, J.; Renard, Ph.; Teles, V.; Violette, S.

    2005-03-01

    ès fins de barrières de perméabilité, qui ont une influence importante sur les écoulement, et, plus encore, sur le transport. Les modè les génétiques récemment apparus ont la capacité de mieux incorporer dans les modèles de faciès les observations géologiques, chose courante dans l'industrie pétrolière, mais insuffisamment développée en hydrogéologie. On conclut que les travaux de recherche ultérieurs devraient s'attacher à développer les modèles de faciès, à les comparer entre eux, et à mettre au point de nouvelles méthodes d'essais in situ, comprenant les méthodes géophysiques, capables de reconnaître la géométrie et les propriétés des faciès. La constitution d'un catalogue mondial de la géométrie et des propriétés des faciès aquifères, ainsi que des méthodes de reconnaissance utilisées pour arriver à la détermination de ces systèmes, serait d'une grande importance pratique pour les applications. La heterogeneidad se puede manejar por medio de la definición de características homogéneas equivalentes, conocidas como promediar o tratando de describir la variabilidad espacial de las características de las rocas a partir de observaciones geológicas y medidas locales. Las técnicas disponibles para estas descripciones son generalmente modelos geoestadísticos continuos o modelos de facies discontinuos como los modelos Boolean, de Indicador o de umbral de Gaussian y el modelo de cadena de Markow. Estos modelos de facies son mas adecuados para tratar la conectvidad de estratos geológicos (por ejemplo canales de alta permeabilidad enterrados o barreras de baja permeabilidad que tienen efectos importantes sobre el flujo y especialmente sobre el transporte en los acuíferos. Los modelos genéticos ofrecen nuevas formas de incorporar más geología en las descripciones de facies, un enfoque que está bien desarollado en la industria petrolera, pero insuficientemente en la hidrogeología. Se concluye que los trabajos futuros deber

  12. Developpement d'une plateforme de calcul d'equilibres chimiques complexes et adaptation aux problemes electrochimiques et d'equilibres contraints

    NASA Astrophysics Data System (ADS)

    Neron, Alex

    Avec l'arrivée de l'environnement comme enjeu mondial, le secteur de l'efficacité énergétique prend une place de plus en plus importante pour les entreprises autant au niveau économique que pour l'image de la compagnie. Par le fait même, le domaine des technologies de l'énergie est un créneau de recherche dont les projets en cours se multiplient. D'ailleurs, un des problèmes qui peut survenir fréquemment dans certaines entreprises est d'aller mesurer la composition des matériaux dans des conditions difficiles d'accès. C'est le cas par exemple de l'électrolyse de l'aluminium qui se réalise à des températures très élevées. Pour pallier à ce problème, il faut créer et valider des modèles mathématiques qui vont calculer la composition et les propriétés à l'équilibre du système chimique. Ainsi, l'objectif global du projet de recherche est de développer un outil de calcul d'équilibres chimiques complexes (plusieurs réactions et plusieurs phases) et l'adapter aux problèmes électrochimiques et d'équilibres contraints. Plus spécifiquement, la plateforme de calcul doit tenir compte de la variation de température due à un gain ou une perte en énergie du système. Elle doit aussi considérer la limitation de l'équilibre due à un taux de réaction et enfin, résoudre les problèmes d'équilibres électrochimiques. Pour y parvenir, les propriétés thermodynamiques telles que l'énergie libre de Gibbs, la fugacité et l'activité sont tout d'abord étudiées pour mieux comprendre les interactions moléculaires qui régissent les équilibres chimiques. Ensuite, un bilan énergétique est inséré à la plateforme de calcul, ce qui permet de calculer la température à laquelle le système est le plus stable en fonction d'une température initiale et d'une quantité d'énergie échangée. Puis, une contrainte cinétique est ajoutée au système afin de calculer les équilibres pseudo-stationnaires en évolution dans le temps. De plus, la

  13. Environmental isotopes (18O, 2H, and 87Sr/86Sr) as a tool in groundwater investigations in the Keta Basin, Ghana

    NASA Astrophysics Data System (ADS)

    Jørgensen, Niels; Banoeng-Yakubo, Bruce

    2001-03-01

    Analyses of environmental isotopes (18O, 2H, and 87Sr/86Sr) are applied to groundwater studies with emphasis on saline groundwater in aquifers in the Keta Basin, Ghana. The 87Sr/86Sr ratios of groundwater and surface water of the Keta Basin primarily reflect the geology and the mineralogical composition of the formations in the catchments and recharge areas. The isotopic compositions of 18O and 2H of deep groundwater have small variations and plot close to the global meteoric water line. Shallow groundwater and surface water have considerably larger variations in isotopic compositions, which reflect evaporation and preservation of seasonal fluctuations. A significant excess of chloride in shallow groundwater in comparison to the calculated evaporation loss is the result of a combination of evaporation and marine sources. Groundwaters from deep wells and dug wells in near-coastal aquifers are characterized by relatively high chloride contents, and the significance of marine influence is evidenced by well-defined mixing lines for strontium isotopes, and hydrogen and oxygen stable isotopes, with isotopic compositions of seawater as one end member. The results derived from environmental isotopes in this study demonstrate that a multi-isotope approach is a useful tool to identify the origin and sources of saline groundwater. Résumé. L'analyse des isotopes du milieu (18O, 2H, et 87Sr/86Sr) a été mise en œuvre pour des études hydrogéologiques portant sur des eaux souterraines salées des aquifères du bassin de Keta (Ghana). Les rapports isotopiques 87Sr/86Sr de l'eau souterraine et de l'eau de surface du bassin de Keta reflètent principalement la géologie et la composition minéralogique des formations des bassins d'alimentation et des zones de recharge. Les compositions isotopiques en 18O et en 2H des eaux souterraines profondes présentent de faibles variations et se placent près de la droite des eaux météoriques mondiales. Les eaux des nappes peu profondes

  14. Environmental isotopes (18O, 2H, and 87Sr/86Sr) as a tool in groundwater investigations in the Keta Basin, Ghana

    NASA Astrophysics Data System (ADS)

    Jørgensen, Niels; Banoeng-Yakubo, Bruce

    2001-03-01

    Analyses of environmental isotopes (18O, 2H, and 87Sr/86Sr) are applied to groundwater studies with emphasis on saline groundwater in aquifers in the Keta Basin, Ghana. The 87Sr/86Sr ratios of groundwater and surface water of the Keta Basin primarily reflect the geology and the mineralogical composition of the formations in the catchments and recharge areas. The isotopic compositions of 18O and 2H of deep groundwater have small variations and plot close to the global meteoric water line. Shallow groundwater and surface water have considerably larger variations in isotopic compositions, which reflect evaporation and preservation of seasonal fluctuations. A significant excess of chloride in shallow groundwater in comparison to the calculated evaporation loss is the result of a combination of evaporation and marine sources. Groundwaters from deep wells and dug wells in near-coastal aquifers are characterized by relatively high chloride contents, and the significance of marine influence is evidenced by well-defined mixing lines for strontium isotopes, and hydrogen and oxygen stable isotopes, with isotopic compositions of seawater as one end member. The results derived from environmental isotopes in this study demonstrate that a multi-isotope approach is a useful tool to identify the origin and sources of saline groundwater. Résumé. L'analyse des isotopes du milieu (18O, 2H, et 87Sr/86Sr) a été mise en œuvre pour des études hydrogéologiques portant sur des eaux souterraines salées des aquifères du bassin de Keta (Ghana). Les rapports isotopiques 87Sr/86Sr de l'eau souterraine et de l'eau de surface du bassin de Keta reflètent principalement la géologie et la composition minéralogique des formations des bassins d'alimentation et des zones de recharge. Les compositions isotopiques en 18O et en 2H des eaux souterraines profondes présentent de faibles variations et se placent près de la droite des eaux météoriques mondiales. Les eaux des nappes peu profondes

  15. Rainforest Pharmacopeia in Madagascar Provides High Value for Current Local and Prospective Global Uses

    PubMed Central

    Golden, Christopher D.; Rasolofoniaina, B. J. Rodolph; Anjaranirina, E. J. Gasta; Nicolas, Lilien; Ravaoliny, Laurent; Kremen, Claire

    2012-01-01

    tropical forests for sustainable use. Botanique de la diversité apporte de la valeur à l’homme par la séquestration du carbone, de l’air et de purification de l’eau, et le provisionnement des aliments sauvages et ethnomedicines. Ici, nous calculons la valeur de ethnomedicines botaniques dans une région de forêt de Madagascar, la zone protégée de Makira, en utilisant une méthode de substitution qui combine les coûts de remplacement et la modélisation des choix. Le bassin versant de Makira peut comprendre environ 0,8% de la diversité botanique mondiale et possède une valeur énorme à la fois dans sa capacité à fournir ethnomedicines botaniques à la population locale et en tant que source de nouveaux médicaments potentiellement pharmaceutiques pour la société dans son ensemble. Environ 241 espèces localement reconnus sont utilisés comme ethnomedicines, y compris 113 espèces d’agricoles ou de mauvaises herbes. Nous assimilé chaque traitement ethnomédicales à la valeur monétaire d’un traitement comparable pharmaceutique ajusté en fonction des préférences personnelles en matière d’efficacité perçue (plutôt que de l’équivalence médicament connu ou supposé). La valeur de l’avantage de ces ethnomedicines botaniques par individu est de $5,40 à 7.90 par année lors de l’utilisation de la valeur des produits pharmaceutiques malgaches fortement subventionnés et de $100,60 à 287,40 lors de l’utilisation de la valeur des produits pharmaceutiques américains. Utilisation de produits pharmaceutiques locales comme des substituts, la valeur par ménage est de $30.24 à 44.30 par an, équivalent à 43–63% du revenu médian des ménages annuelle, ce qui démontre leur importance locale. Utilisation de la valeur des produits pharmaceutiques

  16. Apport de l’écho-doppler artériel des membres inférieurs dans la prise en charge du pied diabétique à l'hôpital Saint-Jean de Dieu de Thiès (Sénégal)

    PubMed Central

    Dia, Aliou Amadou; Affangla, Désiré Alain; Dione, Jean-Michel; Akpo, Géraud; Mbengue, Marie; Ka, Mamadou Mourtalla; Diop, Bernard Marcel

    2015-01-01

    Introduction Le pied diabétique se définit comme l'ensemble des manifestations trophiques du pied survenant chez le diabétique par atteinte nerveuse, artérielle et ou infectieuse. Le pied diabétique est un problème majeur de santé publique à l’échelle mondiale avec un taux d'amputation de membres inférieurs très élevé. L’écho-doppler artériel des membres inférieurs est de nos jours incontournable dans la prise en charge du pied diabétique. Le but de cette étude est de montrer la place prépondérante qu'occupe l’écho-doppler artériel dans le bilan lésionnel du pied diabétique. Méthodes Nous avons mené une étude rétrospective monocentrique incluant 46 patients sur une période de 24 mois, de mars 2012 à mars 2014 à l'hôpital Saint-Jean de Dieu, un des deux hôpitaux de référence de la région de Thiès, doté depuis juillet 2011 d'un centre moderne de traitement du diabète et des maladies cardio-métaboliques (Diabcarmet). Dans les critères d'inclusion, nous avons sélectionné tous les patients diabétiques adressés pour un écho-doppler artériel des membres inférieurs dans le cadre d'une prise en charge du pied diabétique. Etaient exclus de l’étude, les patients artéritiques non-diabétiques et les patients diabétiques asymptomatiques référés pour un bilan écho-doppler de routine. Résultats Le sex-ratio était de 1.42 (27 hommes pour 19 femmes). L’âge moyen des patients était de 62,86 ans avec des extrêmes de 23 et 88 ans. 60% des patients (n=28) étaient âgés entre 50 et 70 ans. Le diabète de type 2 était retrouvé chez 95% des patients (n=44) alors que le diabète de type 1 représentait 5% (n=2). La moyenne d’évolution du diabète était estimée à 8 ans, avec des extrêmes de 2 et 20 ans. On notait une atteinte du pied droit chez 24 patients, une atteinte du pied gauche chez 18 patients et une atteinte bilatérale chez 4 patients. La plupart du temps, les lésions du pied diabétique survenaient

  17. Relevé postnatal Rourke 2014

    PubMed Central

    Riverin, Bruno; Li, Patricia; Rourke, Leslie; Leduc, Denis; Rourke, James

    2015-01-01

    Résumé Objectif Mettre à jour la version de 2011 du Relevé postnatal Rourke (RPR) à la suite d’une révision des meilleures données probantes récentes sur le suivi de la santé des nourrissons et des enfants de la naissance jusqu’à l’âge de 5 ans. Qualité des données La qualité des données a été cotée en fonction de l’ancien système de classification du Groupe d’étude canadien sur les soins de santé préventifs (jusqu’à 2006) et l’approche de détermination, d’élaboration et d’évaluation des recommandations (GRADE). Message principal De nouveaux faits scientifiques ont été pris en compte dans les recommandations du RPR 2014 en ce qui a trait au suivi de la croissance, à la nutrition, à l’éducation et aux conseils, au développement, à l’examen physique et à l’immunisation. La croissance est surveillée à l’aide des courbes de l’Organisation mondiale de la Santé qui ont été révisées en 2014. On devrait introduire les aliments solides en fonction de l’état de préparation du nourrisson et ces produits devraient contenir du fer. Il n’est actuellement plus recommandé de retarder l’introduction des allergènes alimentaires courants pour prévenir les allergies. Il faut promouvoir l’utilisation d’une tasse sans couvercle au lieu d’une tasse à bec dès l’âge de 12 mois. La section sur l’éducation et les conseils porte sur les blessures causées par du mobilier instable, ainsi que l’utilisation d’un siège d’auto orienté vers l’arrière jusqu’à 2 ans. Elle comporte aussi de l’information sur les saines habitudes de sommeil, la prévention de la maltraitance des enfants, la vie saine et active et la sédentarité de la famille, de même que l’hygiène buccale. On a aussi ajouté à cette section une nouvelle catégorie consacrée à la santé environnementale pour tenir compte des effets des dangers environnementaux sur la santé des enfants. Le RPR a recours à une

  18. Préface

    NASA Astrophysics Data System (ADS)

    Ouerdane, Youcef; Laporte, Pierre

    2005-06-01

    L'objectif de la série de colloques UVX est de réunir, au rythme d'une fois tous les deux ans, les scientifiques et industriels travaillant dans le domaine du développement des sources de photon de grande énergie (UV, VUV, et X) et de leurs applications. En particulier cette manifestation est l'occasion de faire se rencontrer une communauté très pluridisciplinaire (physique, chimie, biologie, sciences de l'univers) liée à des domaines en forte évolution technologique (lasers et rayonnement synchrotron notamment). Le colloque UVX 2004 s'est tenu au Palais des Congrès de Saint-Étienne (42000) du 7 au 11 juin 2004. La période écoulée depuis l'édition précédente (Oléron 2002) a été particulièrement active dans tous les domaines concernés : grands projets de sources, méthodes de diagnostic au sens large. Une nouvelle fois on constate que le bref et l'ultra-bref ont une place privilégiée, qu'il s'agisse du travail sur les accélérateurs ou sur les lasers qui, bien sûr, dans la course aux temps courts remportent la palme avec la présence de spécialistes du domaine attoseconde. La communauté représentée a la chance d'être en prise directe avec de très grands projets en phase active de réalisation comme le Laser Megajoule (LMJ), la source SOLEIL, et un projet d'ampleur plus modeste mais remarquable dans son domaine : la source LASERIX d'Orsay/Palaiseau. On pourra citer aussi le projet Arc en Ciel qui, lui, est encore au stade de sa définition. - SOLEIL, source de nouvelle génération de rayonnement synchrotron (plateau de Saclay) est dans une phase active de réalisation : achèvement de l'infrastructure en 2005 et injection du 1o faisceau dans l'anneau de stockage prévu également en 2005. Cette source devrait être la meilleure au monde dans le domaine VUV/X mous, tout en restant très polyvalente (brillance, accordabilité, structure temporelle, polarisation) et complémentaire de l'ESRF. Au final on disposera de 21 lignes de lumi

  19. Crystallographic and optical properties and band structures of CuInSe2, CuIn3Se5, and CuIn5Se8 phases in Cu-poor Cu2Se-In2Se3 pseudo-binary system

    NASA Astrophysics Data System (ADS)

    Maeda, Tsuyoshi; Gong, Weiyan; Wada, Takahiro

    2016-04-01

    We prepared CuInSe2 and Cu-poor Cu-In-Se (CIS) phases such as CuIn3Se5 and CuIn5Se8 in the composition of (1 - x)Cu2Se-(x)In2Se3 with 0.5 ≤ x ≤ 1.0. The crystal structure of the sample changed from chalcopyrite-type CuInSe2 to hexagonal CuIn5Se8 through stannite-type CuIn3Se5 with increasing x (decreasing Cu/In ratio). The band-gap energies of Cu-poor CIS samples, i.e., CuIn3Se5 (1.17 eV) and CuIn5Se8 (1.22-1.24 eV), are larger than that of chalcopyrite-type CuInSe2 (0.99 eV). The energy levels of the valence band maxima (VBMs) were estimated from the ionization energy by photoemission yield spectroscopy (PYS) measurements. The energy levels of the VBMs of the Cu-poor CIS samples decrease rapidly with decreasing Cu/In ratio. The ionization energy of stannite-type CuIn3Se5 is 0.4 eV larger than that of chalcopyrite-type CuInSe2. The ionization energy of CuIn5Se8 is 0.1-0.3 eV larger than that of CuIn3Se5. These results show that the energy position of the VBM from the vacuum level of Cu-poor CIS phases, such as CuIn3Se5 and CuIn5Se8, is deeper than that of CuInSe2. To understand the electronic structure of Cu-poor CIS compounds, we performed first-principles band structure calculations on stannite-type CuIn5Se8 and a reference compound, tetragonal chalcopyrite-type CuInSe2, using the HSE06 nonlocal screened hybrid density functional. The calculated band-gap energy of tetragonal stannite-type CuIn5Se8 (1.19 eV) is larger than that of chalcopyrite-type CuInSe2 (0.94 eV).

  20. Direct ion flux measurements at high-pressure-depletion conditions for microcrystalline silicon deposition

    SciTech Connect

    Bronneberg, A. C.; Kang, X.; Palmans, J.; Janssen, P. H. J.; Lorne, T.; Creatore, M.; Sanden, M. C. M. van de

    2013-08-14

    The contribution of ions to the growth of microcrystalline silicon thin films has been investigated in the well-known high-pressure-depletion (HPD) regime by coupling thin-film analysis with plasma studies. The ion flux, measured by means of a capacitive probe, has been studied in two regimes, i.e., the amorphous-to-microcrystalline transition regime and a low-to-high power regime; the latter regime had been investigated to evaluate the impact of the plasma power on the ion flux in collisional plasmas. The ion flux was found not to change considerably under the conditions where the deposited material undergoes a transition from the amorphous to the microcrystalline silicon phase; for solar-grade material, an ion-to-Si deposition flux of ∼0.30 has been determined. As an upper-estimation of the ion energy, a mean ion energy of ∼19 eV has been measured under low-pressure conditions (<1 mbar) by means of a retarding field energy analyzer. Combining this upper-estimate with an ion per deposited Si atom ratio of ∼0.30, it is concluded that less than 6 eV is available per deposited Si atom. The addition of a small amount of SiH{sub 4} to an H{sub 2} plasma resulted in an increase of the ion flux by about 30% for higher power values, whereas the electron density, deduced from optical emission spectroscopy analysis, decreased. The electron temperature, also deduced from optical emission spectroscopy analysis, reveals a slight decrease with power. Although the dominant ion in the HPD regime is SiH{sub 3}{sup +}, i.e., a change from H{sub 3}{sup +} in pure hydrogen HPD conditions, the measured larger ion loss can be explained by assuming steeper electron density profiles. These results, therefore, confirm the results reported so far: the ion-to-Si deposition flux is relatively large but has neither influence on the microcrystalline silicon film properties nor on the phase transition. Possible explanations are the reported high atomic hydrogen to deposition flux ratio

  1. Placental Genome and Maternal-Placental Genetic Interactions: A Genome-Wide and Candidate Gene Association Study of Placental Abruption

    PubMed Central

    Denis, Marie; Enquobahrie, Daniel A.; Tadesse, Mahlet G.; Gelaye, Bizu; Sanchez, Sixto E.; Salazar, Manuel; Ananth, Cande V.; Williams, Michelle A.

    2014-01-01

    While available evidence supports the role of genetics in the pathogenesis of placental abruption (PA), PA-related placental genome variations and maternal-placental genetic interactions have not been investigated. Maternal blood and placental samples collected from participants in the Peruvian Abruptio Placentae Epidemiology study were genotyped using Illumina’s Cardio-Metabochip platform. We examined 118,782 genome-wide SNPs and 333 SNPs in 32 candidate genes from mitochondrial biogenesis and oxidative phosphorylation pathways in placental DNA from 280 PA cases and 244 controls. We assessed maternal-placental interactions in the candidate gene SNPS and two imprinted regions (IGF2/H19 and C19MC). Univariate and penalized logistic regression models were fit to estimate odds ratios. We examined the combined effect of multiple SNPs on PA risk using weighted genetic risk scores (WGRS) with repeated ten-fold cross-validations. A multinomial model was used to investigate maternal-placental genetic interactions. In placental genome-wide and candidate gene analyses, no SNP was significant after false discovery rate correction. The top genome-wide association study (GWAS) hits were rs544201, rs1484464 (CTNNA2), rs4149570 (TNFRSF1A) and rs13055470 (ZNRF3) (p-values: 1.11e-05 to 3.54e-05). The top 200 SNPs of the GWAS overrepresented genes involved in cell cycle, growth and proliferation. The top candidate gene hits were rs16949118 (COX10) and rs7609948 (THRB) (p-values: 6.00e-03 and 8.19e-03). Participants in the highest quartile of WGRS based on cross-validations using SNPs selected from the GWAS and candidate gene analyses had a 8.40-fold (95% CI: 5.8–12.56) and a 4.46-fold (95% CI: 2.94–6.72) higher odds of PA compared to participants in the lowest quartile. We found maternal-placental genetic interactions on PA risk for two SNPs in PPARG (chr3∶12313450 and chr3∶12412978) and maternal imprinting effects for multiple SNPs in the C19MC and IGF2/H19 regions

  2. Diffusion and the Thermal Stability of Amorphous Copper-Zirconium

    NASA Astrophysics Data System (ADS)

    Stelter, Eric Carl

    Measurements have been made of diffusion and thermal relaxation in amorphous Cu(,50)Zr(,50). Samples were prepared by melt-spinning under vacuum. Diffusion measurements were made over the temperature range from 317 to 385 C, using Ag and Au as substitutional impurities, by means of Auger electron spectrometry (AES) and Rutherford backscattering spectrometry (RBS). Thermal measurements were made by differential scanning calorimetry (DSC) up to 550 C. The diffusion coefficients of Ag and Au in amorphous Cu(,50)Zr(,50) are found to be somewhat higher than, but very close in magnitude to the coefficient of self-diffusion in crystalline Cu at the same temperatures. The activation energies for diffusion in the amorphous alloy are 0.72 to 1.55 eV/atom, much closer to the activation energy for self-diffusion in liquid Cu, 0.42 eV/atom, than that for the crystalline solid, 2.19 eV/atom. The mechanism for diffusion in the amorphous metal is presumably quite different from the monovacancy mechanism dominant in the crystalline solid. The pre-exponential terms are found to be extremely small, on the order of 10('-10) to 10('-11) cm('2)/sec for Ag diffusion. This indicates that diffusion in amorphous Cu(,50)Zr(,50) may involve an extended defect of 10 or more atoms. Analysis of the data in terms of the free -volume model also lends strength to this conclusion and indicates that the glass is composed of liquid-like clusters of 15 to 20 atoms. The initial stage of relaxation in amorphous CuZr occurs with a spectrum of activation energies. The lowest activation energy involved, 0.78 eV/atom, is almost identical to the average activation energy of Ag diffusion in the glass, 0.77 eV/atom, indicating that relaxation occurs primarily through diffusion. The activation energy of crystallization, determined by Kissinger's method, is 3.10 eV/atom. The large difference, on the order of 2.3 eV/atom, between the activation energies of crystallization and diffusion is attributed to the energy

  3. Cytotoxic Compounds from the Saudi Red Sea Sponge Xestospongia testudinaria

    PubMed Central

    El-Gamal, Ali A.; Al-Massarani, Shaza M.; Shaala, Lamiaa A.; Alahdald, Abdulrahman M.; Al-Said, Mansour S.; Ashour, Abdelkader E.; Kumar, Ashok; Abdel-Kader, Maged S.; Abdel-Mageed, Wael M.; Youssef, Diaa T. A.

    2016-01-01

    Bioassay-guided fractionation of the organic extract of the Red Sea sponge Xestospongia testudinaria led to the isolation of 13 compounds including two new sterol esters, xestosterol palmitate (2) and xestosterol ester of l6′-bromo-(7′E,11′E,l5′E)-hexadeca-7′,11′,l5′-triene-5′,13′-diynoic acid (4), together with eleven known compounds: xestosterol (1), xestosterol ester of 18′-bromooctadeca-7′E,9′E-diene-7′,15′-diynoic acid (3), and the brominated acetylenic fatty acid derivatives, (5E,11E,15E,19E)-20-bromoeicosa-5,11,15,19-tetraene-9,17-diynoic acid (5), 18,18-dibromo-(9E)-octadeca-9,17-diene-5,7-diynoic acid (6), 18-bromooctadeca-(9E,17E)-diene-7,15-diynoic acid (7), 18-bromooctadeca-(9E,13E,17E)-triene-7,15-diynoic acid (8), l6-bromo (7E,11E,l5E)hexadeca-7,11,l5-triene-5,13-diynoic acid (9), 2-methylmaleimide-5-oxime (10), maleimide-5-oxime (11), tetillapyrone (12), and nortetillapyrone (13). The chemical structures of the isolated compounds were accomplished using one- and two-dimensional NMR, infrared and high-resolution electron impact mass spectroscopy (1D, 2D NMR, IR and HREIMS), and by comparison with the data of the known compounds. The total alcoholic and n-hexane extracts showed remarkable cytotoxic activity against human cervical cancer (HeLa), human hepatocellular carcinoma (HepG-2), and human medulloblastoma (Daoy) cancer cell lines. Interestingly, the dibrominated C18-acetylenic fatty acid (6) exhibited the most potent growth inhibitory activity against these cancer cell lines followed by Compounds 7 and 9. Apparently, the dibromination of the terminal olefinic moiety has an enhanced effect on the cytotoxic activity. PMID:27128926

  4. Ethanol and Water Adsorption on Transition-Metal 13-Atom Clusters: A Density Functional Theory Investigation within van der Waals Corrections.

    PubMed

    Zibordi-Besse, Larissa; Tereshchuk, Polina; Chaves, Anderson S; Da Silva, Juarez L F

    2016-06-23

    Transition-metal (TM) nanoparticles supported on oxides or carbon black have attracted much attention as potential catalysts for ethanol steam reforming reactions for hydrogen production. To improve the performance of nanocatalysts, a fundamental understanding of the interaction mechanism between water and ethanol with finite TM particles is required. In this article, we employed first-principles density functional theory with van der Waals (vdW) corrections to investigate the interaction of ethanol and water with TM13 clusters, where TM = Ni, Cu, Pd, Ag, Pt, and Au. We found that both water and ethanol bind via the anionic O atom to onefold TM sites, while at higher-energy structures, ethanol binds also via the H atom from the CH2 group to the TM sites, which can play an important role at real catalysts. The putative global minimum TM13 configurations are only slightly affected upon the adsorption of water or ethanol; however, for few systems, the compact higher-energy icosahedron structure changes its configuration upon ethanol or water adsorption. That is, those configurations are only shallow local minimums in the phase space. Except few deviations, we found similar trends for the magnitude of the adsorption energies of water and ethanol, that is, Ni13 > Pt13 > Pd13 and Cu13 > Au13 > Ag13, which is enhanced by the addition of the vdW correction (i.e., from 4% to 62%); however, the trend is the same. We found that the magnitude of the adsorption energy increases by shifting the center of gravity of the d-states toward the highest occupied molecular orbital. On the basis of the Mulliken and Hirshfeld charge analysis, as well as electron density differences, we identified the location of the charge redistribution and a tiny charge transfer (from 0.01 e to 0.19 e) from the molecules to the TM13 clusters. Our vibrational analysis indicates the red shifts in the OH modes upon binding of both water and ethanol molecules to the TM13 clusters, suggesting a weakening of

  5. LOWER LIMITS ON ULTRAHIGH-ENERGY COSMIC RAY AND JET POWERS OF TeV BLAZARS

    SciTech Connect

    Razzaque, Soebur; Dermer, Charles D.; Finke, Justin D.

    2012-02-01

    Lower limits on the power emitted in ultrahigh-energy cosmic rays (UHECRs), which are assumed to be protons with energy {approx}> 10{sup 17}-10{sup 20} eV, are derived for TeV blazars with the assumption that the observed TeV {gamma}-rays are generated due to interactions of these protons with cosmic microwave photons. The limits depend on the spectrum of the injected UHECR protons. While for a -2.2 injection spectrum the lower limits on the powers emitted in UHECRs by 1ES 0229+200, 1ES 1101-232, and 1ES 0347-121 are lower than their respective synchrotron luminosities ({approx}10{sup 46} erg s{sup -1}), in the case of 1ES 1426+428 it exceeds the corresponding synchrotron luminosity by up to an order of magnitude. The proposed Auger North Observatory should be able to detect 4 Multiplication-Sign 10{sup 19} eV cosmic-ray (CR) protons from 1ES 1426+428 within a few years of operation and test the TeV {gamma}-ray production model by UHECR energy losses while propagating along the line of sight or constrain the intergalactic magnetic field to be larger than {approx}10{sup -16} G in case of no detection. The lower limits on the apparent-isotropic jet power from accelerated 10{sup 10}-10{sup 20} eV proton spectra in the blazar jet is of the order of the Eddington luminosity of a 10{sup 9} M{sub Sun} black hole for a CR injection spectrum -2.2 or harder for all blazars considered except for 1ES 1426+428. In the case of the latter, the apparent-isotropic jet power exceeds the Eddington luminosity by an order of magnitude. For an injection spectrum softer than -2.2, as is required to fit the observed CR data above {approx}10{sup 17}-10{sup 18} eV, the Eddington luminosity is exceeded by the lower limits on the jet power for all blazars considered.

  6. Synthesis, Structure, Multiband Optical, and Electrical Conductive Properties of a 3D Open Cubic Framework Based on [Cu8Sn6S24](z-) Clusters.

    PubMed

    Zhang, Xian; Wang, Qiuran; Ma, Zhimin; He, Jianqiao; Wang, Zhe; Zheng, Chong; Lin, Jianhua; Huang, Fuqiang

    2015-06-01

    Two compounds with the formulas of Na4Cu32Sn12S48·4H2O and K11Cu32Sn12S48·4H2O were synthesized via flux (with thiourea as reactive flux) and hydrothermal method, respectively. The black crystals of Na4Cu32Sn12S48·4H2O and K11Cu32Sn12S48·4H2O both crystallize in the cubic space group of Fm3̅c with the cell constants a = 17.921(2) Å and a = 18.0559(6) Å, respectively. The crystal structures feature a 3D open-framework with the unique [Cu8Sn6S24](z-) (z = 13 for Na4Cu32Sn12S48·4H2O; z = 14.75 for K11Cu32Sn12S48·4H2O) clusters acting as building blocks. The [Cu8Sn6S24](z-) cluster of the Th symmetry is built up by eight [CuS3] triangles and six [SnS4] tetrahedra. The powder samples were investigated by X-ray diffraction and optical absorption measurements. Both phase-pure compounds show multiabsorption character with a main absorption edge (2.0 eV for Na4Cu32Sn12S48·4H2O and 1.9 eV for K11Cu32Sn12S48·4H2O) and an additional absorption peak (1.61 eV for Na4Cu32Sn12S48·4H2O and 1.52 eV for K11Cu32Sn12S48·4H2O), which are perfectly consistent with the first-principle calculation results. The analyses of the density of states further reveal that the two optical absorption bands in each compound are attributed to the two transitions of Cu-3d-S-3p → Sn-5s. The multiband nature of two compounds also enhances photocatalytic activity under visible light irradiation, with which the degradation of methyl blue over Na4Cu32Sn12S48·4H2O reached 100% in 3 h. The 3D open-framework features also facilitate the ionic conductivity nature of the Na4Cu32Sn12S48·4H2O compound, which achieved ∼10(-5) S/cm at room temperature. PMID:25955506

  7. Energy Intake, Profile, and Dietary Sources in the Spanish Population: Findings of the ANIBES Study

    PubMed Central

    Ruiz, Emma; Ávila, José Manuel; Valero, Teresa; del Pozo, Susana; Rodriguez, Paula; Aranceta-Bartrina, Javier; Gil, Ángel; González-Gross, Marcela; Ortega, Rosa M.; Serra-Majem, Lluis; Varela-Moreiras, Gregorio

    2015-01-01

    Energy intake, and the foods and beverages contributing to that, are considered key to understanding the high obesity prevalence worldwide. The relative contributions of energy intake and expenditure to the obesity epidemic, however, remain poorly defined in Spain. The purpose of this study was to contribute to updating data of dietary energy intake and its main sources from food and beverages, according to gender and age. These data were derived from the ANIBES (“Anthropometry, Intake, and Energy Balance in Spain”) study, a cross-sectional study of a nationally representative sample of the Spanish population (from 9–75 years old). A three-day dietary record, collected by means of a tablet device, was used to obtain information about food and beverage consumption and leftovers. The final sample comprised 2009 individuals (1,013 men, 996 women). The observed mean dietary energy intake was 7.6 ± 2.11 MJ/day (8.2 ± 2.22 MJ/day for men and 6.9 ± 1.79 MJ/day for women). The highest intakes were observed among adolescents aged 13–17 years (8.4 MJ/day), followed by children 9–12 years (8.2 ± 1.80 MJ/day), adults aged 18–64 (7.6 ± 2.14 MJ/day) and older adults aged 65–75 years (6.8 ± 1.88 MJ/day). Cereals or grains (27.4%), meats and derivatives (15.2%), oils and fats (12.3%), and milk and dairy products (11.8%) contributed most to daily energy intake. Energy contributions from non-alcoholic beverages (3.9%), fish and shellfish (3.6%), sugars and sweets (3.3%) and alcoholic beverages (2.6%) were moderate to minor. Contributions to caloric profile were 16.8%E from proteins; 41.1%E from carbohydrates, including 1.4%E from fiber; 38.5%E from fats; and 1.9%E from alcohol intake. We can conclude that energy intake is decreasing in the Spanish population. A variety of food and beverage groups contribute to energy intake; however, it is necessary to reinforce efforts for better adherence to the traditional Mediterranean diet. PMID:26076230

  8. Measurements of radiative material properties for astrophysical plasmas.

    SciTech Connect

    Bailey, James E.

    2010-10-01

    . These profiles have been studied in past experiments, but puzzles emerging from recent white dwarf analysis have raised questions about the accuracy of the line profile models. Proof-of-principle data has been acquired that indicates radiation-heated quiescent plasmas can be produced with {approx} 1 eV temperature and 10{sup 17}-10{sup 19} e/cc densities, in an {approx} 20cm{sup 3} volume. Such plasmas would provide a valuable platform for investigating numerous line profile questions.

  9. Hybrid germanium iodide perovskite semiconductors: active lone pairs, structural distortions, direct and indirect energy gaps, and strong nonlinear optical properties.

    PubMed

    Stoumpos, Constantinos C; Frazer, Laszlo; Clark, Daniel J; Kim, Yong Soo; Rhim, Sonny H; Freeman, Arthur J; Ketterson, John B; Jang, Joon I; Kanatzidis, Mercouri G

    2015-06-01

    The synthesis and properties of the hybrid organic/inorganic germanium perovskite compounds, AGeI3, are reported (A = Cs, organic cation). The systematic study of this reaction system led to the isolation of 6 new hybrid semiconductors. Using CsGeI3 (1) as the prototype compound, we have prepared methylammonium, CH3NH3GeI3 (2), formamidinium, HC(NH2)2GeI3 (3), acetamidinium, CH3C(NH2)2GeI3 (4), guanidinium, C(NH2)3GeI3 (5), trimethylammonium, (CH3)3NHGeI3 (6), and isopropylammonium, (CH3)2C(H)NH3GeI3 (7) analogues. The crystal structures of the compounds are classified based on their dimensionality with 1–4 forming 3D perovskite frameworks and 5–7 1D infinite chains. Compounds 1–7, with the exception of compounds 5 (centrosymmetric) and 7 (nonpolar acentric), crystallize in polar space groups. The 3D compounds have direct band gaps of 1.6 eV (1), 1.9 eV (2), 2.2 eV (3), and 2.5 eV (4), while the 1D compounds have indirect band gaps of 2.7 eV (5), 2.5 eV (6), and 2.8 eV (7). Herein, we report on the second harmonic generation (SHG) properties of the compounds, which display remarkably strong, type I phase-matchable SHG response with high laser-induced damage thresholds (up to ∼3 GW/cm(2)). The second-order nonlinear susceptibility, χS(2), was determined to be 125.3 ± 10.5 pm/V (1), (161.0 ± 14.5) pm/V (2), 143.0 ± 13.5 pm/V (3), and 57.2 ± 5.5 pm/V (4). First-principles density functional theory electronic structure calculations indicate that the large SHG response is attributed to the high density of states in the valence band due to sp-hybridization of the Ge and I orbitals, a consequence of the lone pair activation. PMID:25950197

  10. Phenotypic and molecular antibiotic resistance profile of Enterococcus faecalis and Enterococcus faecium isolated from different traditional fermented foods.

    PubMed

    Sánchez Valenzuela, Antonio; Lavilla Lerma, Leyre; Benomar, Nabil; Gálvez, Antonio; Pérez Pulido, Rubén; Abriouel, Hikmate

    2013-02-01

    A collection of 55 enterococci (41 Enterococcus faecium and 14 E. faecalis strains) isolated from various traditional fermented foodstuffs of both animal and vegetable origins, and water was evaluated for resistance against 15 antibiotics. Lower incidence of resistance was observed with gentamicin, ampicillin, penicillin and teicoplanin. However, a high incidence of antibiotic resistance was detected for rifampicin (12 out of 14 of isolates), ciprofloxacin (9/14), and quinupristin/dalfopristin (8/14) in E. faecalis strains. Enterococcus faecium isolates were resistant to rifampicin (25/41), ciprofloxacin (23/41), erythromycin (18/41), levofloxacin (16/41), and nitrofurantoin (15/41). One Enterococcus faecalis and two E. faecium strains were resistant to vancomycin (MIC>16 μg/mL). Among 55 isolates, 27 (19 E. faecium and eight E. faecalis) were resistant to at least three antibiotics. High level of multidrug resistance to clinically important antibiotics was detected in E. faecalis strains (57% of E. faecalis versus 46% of E. faecium), which showed resistance to six to seven antibiotics, especially those isolated from foods of animal origin. So, it is necessary to re-evaluate the use of therapeutic antibiotics in stock farms at both regional and international levels due to the high number of multiple resistant (MR) bacteria. Fifty-six MR E. faecalis and E. faecium strains selected from this and previous studies (Valenzuela et al., 2008, 2010) were screened by polymerase chain reaction for antibiotic resistance genes, revealing the presence of tet(L), tet(M), ermB, cat, efrA, efrB, mphA, or msrA/B genes. The ABC Multidrug Efflux Pump EfrAB was detected in 96% of E. faecalis strains and also in 13% of E. faecium strains; this is the first report describing EfrAB in this enterococcal species. The efflux pump-associated msrA/B gene was detected in 66.66% of E. faecium strains, but not in E. faecalis strains. PMID:23259502

  11. Zn-VI/Cu2O Heterojunctions for Earth-Abundant Photovoltaics

    NASA Astrophysics Data System (ADS)

    Wilson, Samantha

    The need for sustainable energy production motivates the study of photovoltaic materials, which convert energy from sunlight directly into electricity. This work has focused on the development of Cu2O as an earth-abundant solar absorber due to the abundance of its constituent elements in the earth's crust, its suitable band gap, and its potential for low cost processing. Crystalline wafers of Cu2O with minority carrier diffusion lengths on the order of microns can be manufactured in a uniquely simple fashion --- directly from copper foils by thermal oxidation. Furthermore, Cu2Ohas an optical band gap of 1.9 eV, which gives it a detailed balance energy conversion efficiency of 24.7% and the possibility for an independently connected Si/Cu 2O dual junction with a detailed balance efficiency of 44.3%. However, the highest energy conversion efficiency achieved in a photovoltaic device with a Cu2O absorber layer is currently only 5.38% despite the favorable optical and electronic properties listed above. There are several challenges to making a Cu2O photovoltaic device, including an inability to dope the material, its relatively low chemical stability compared to other oxides, and a lack of suitable heterojunction partners due to an unusually small electron affinity. We have addressed the low chemical stability, namely the fact that Cu2O is an especially reactive oxide due to its low enthalpy of formation (DeltaHf0 = -168.7 kJ/mol), by developing a novel surface preparation technique. We have addressed the lack of suitable heterojunction partners by investigating the heterojunction band alignment of several Zn-VI materials with Cu 2O. Finally, We have addressed the typically high series resistance of Cu2O wafers by developing methods to make very thin, bulk Cu 2O, including devices on Cu2O wafers as thin as 20 microns. Using these methods we have been able to achieve photovoltages over 1 V, and have demonstrated the potential of a new heterojunction material, Zn(O,S).

  12. Field Analogues of Shallow-water Hydrocarbon Seepages in the Pleistocene Argille Azzurre Formation: the Chimneys Field of Enza River, Northern Apennines, Italy

    NASA Astrophysics Data System (ADS)

    Oppo, D.; Capozzi, R.; Dinelli, E.; Negri, A.; Montagna, P.; Picotti, V.; Scarponi, D.; Taviani, M.

    2012-12-01

    The geologically young Northern Apennines contain various natural seeps documenting a variability of reservoirs and fluids in terms of origin, age and evolution. Hydrocarbon and saline water seepages are controlled by the structures of the chain and the foredeep. In the geological record, the witness of these natural seepages are represented by authigenic carbonates. Their isotopic content allows to understand the carbon source and the processes of carbonate precipitation. The better known regional examples of Methane Derived Authigenic Carbonates (MDAC) and chemoherm build-ups, clustered in the Upper Miocene and Lower-Upper Pliocene successions, are formed in deep water (> 300 m) sediments. Occurrences in shallow water (shelf) settings have never been reported. Our case study describes the palisade chimneys field, recently exposed along the Enza riverbanks in the Northern Apennines in the Argille Azzurre Formation (blue mudstones) of Pleistocene age. The paleontological content (mainly bivalves) documents that this unit was deposited in an open marine muddy shelfal setting, in a bathymetric range of about 50-70 m, with local anoxic condition, documented by benthic foraminifer assemblages. The succession is biostratigraphically dated at the Early Pleistocene (Calabrian, nannoplancton zone MNN19e). A number of subvertical, metric-high columnar chimneys, ranging in diameter from 10 to 35 cm, in association with discontinuous planar carbonate concretions, intervening along the bedding planes, outcrop within the mudstones. Such concretions are clearly formed by the moderate cementation of the hosting pelitic sediments. The tubular concretions show central conduits running along the whole length, locally filled by sediments. The grain size within the concretions is homogeneous, both in the chimneys and planar concretions and irrespective of the bedding planes, suggesting a process of transport and homogenization prior to the cementation. Within the Enza river succession

  13. Low-temperature self-limiting atomic layer deposition of wurtzite InN on Si(100)

    NASA Astrophysics Data System (ADS)

    Haider, Ali; Kizir, Seda; Biyikli, Necmi

    2016-04-01

    In this work, we report on self-limiting growth of InN thin films at substrate temperatures as low as 200 °C by hollow-cathode plasma-assisted atomic layer deposition (HCPA-ALD). The precursors used in growth experiments were trimethylindium (TMI) and N2 plasma. Process parameters including TMI pulse time, N2 plasma exposure time, purge time, and deposition temperature have been optimized for self-limiting growth of InN with in ALD window. With the increase in exposure time of N2 plasma from 40 s to 100 s at 200 °C, growth rate showed a significant decrease from 1.60 to 0.64 Å/cycle. At 200 °C, growth rate saturated as 0.64 Å/cycle for TMI dose starting from 0.07 s. Structural, optical, and morphological characterization of InN were carried out in detail. X-ray diffraction measurements revealed the hexagonal wurtzite crystalline structure of the grown InN films. Refractive index of the InN film deposited at 200 °C was found to be 2.66 at 650 nm. 48 nm-thick InN films exhibited relatively smooth surfaces with Rms surface roughness values of 0.98 nm, while the film density was extracted as 6.30 g/cm3. X-ray photoelectron spectroscopy (XPS) measurements depicted the peaks of indium, nitrogen, carbon, and oxygen on the film surface and quantitative information revealed that films are nearly stoichiometric with rather low impurity content. In3d and N1s high-resolution scans confirmed the presence of InN with peaks located at 443.5 and 396.8 eV, respectively. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) further confirmed the polycrystalline structure of InN thin films and elemental mapping revealed uniform distribution of indium and nitrogen along the scanned area of the InN film. Spectral absorption measurements exhibited an optical band edge around 1.9 eV. Our findings demonstrate that HCPA-ALD might be a promising technique to grow crystalline wurtzite InN thin films at low substrate temperatures.

  14. Sea surface temperatures from the southern Benguela region from the Pliocene and Pleistocene: tracking Agulhas Current input into the SE Atlantic

    NASA Astrophysics Data System (ADS)

    Petrick, B. F.; McClymont, E.; Felder, S.; Lloyd, J. M.; Leng, M. J.

    2011-12-01

    The Pliocene and-Pleistocene epochs provide a way to understand the effect of past climate changes on key ocean currents. Here, we show results from ODP Site1087 (31.28'S, 15.19'E, 1374m water depth) to investigate changes in ocean circulation over the period of the mid-Pliocene warm period 3.0-3.5 Ma and compare these to the time of the 100 kyr Pleistocene glacial cycles. ODP 1087 is located in the South-eastern Atlantic Ocean, outside of the Benguela upwelling region; reconstructing the temperature history of the site will therefore provide an important data set from a part of the ocean that has few orbital-scale and continuous Pliocene temperature reconstructions. ODP 1087 can be used to investigate the history of the heat and salt transfer to the Atlantic Ocean from the Indian Ocean via the Agulhas Retroflection, which plays an important part in the global thermohaline circulation (Lutjeharms, 2007). Climate models and reconstructions for the most recent glacial-interglacial cycles have shown that changes to the strength of the heat transfer may cause major climatic changes and may play a role in transitions from glacial to interglacial events (Knorr & Lohmann, 2003). It is unknown how this transfer reacted to generally warmer global temperatures during the mid-Pliocene. Because the mid-Pliocene is seen as a model for future climate change it might provide a model for ocean circulations in a warmer world. Our approach is to apply several organic geochemistry proxies and foraminiferal analyses to reconstruct the history of ODP 1087. The UK37' index records differences in the unsaturated bonds in the C37 alkenones to reconstruct sea surface temperatures (Brassell et al., 1986). We present SSTs generated for the mid-Pliocene Warm period with a resolution of 4000 years. We compare this data to the time of the 100 kyr glacial cycles during the late Pleistocene. Even though ODP 1087 is located outside the Benguela upwelling system, it has lower Pliocene temperatures

  15. Permeability of the South Ellwood Fault, Offshore Santa Barbara, California

    NASA Astrophysics Data System (ADS)

    Boles, J. R.; Horner, S.; Garven, G.

    2009-12-01

    Natural methane migrates from faulted and fractured siliceous Miocene-age shale hydrocarbon reservoirs to the seabed of the Santa Barbara channel in southern California. At one locality near Platform Holly, about 2 km offshore, where seepage is monitored from two steel and concrete tents on the seabed (area~1860 m2), seepage rate can be related to wells producing 1 km beneath the tents. A new well, perforated at 914 m (3000 ft) beneath the collection tents, directly affects the seepage into the tents. When the well is shut down, seepage production rates increase at a constant rate of 45.3 m3 day/day (1.6 MCF/day/day) to 31.2 m3 day/day (1.1 MCF/day/day) over shutdown periods ranging from 21 days in 2003 to 45 days in 2005, respectively. Using seismic and well data, a fault with about 60 m (200 ft) of throw has been identified running along the crest of the South Ellwood anticline. Using these changes in flow rate, the estimated pressure differences between the seep tent and the perforation intervals in the well, we have calculated the permeability with respect to gas for the 914 m fracture/fault flow path, assuming steady Darcian flow, to be about 3.0E-14 m2 (30 millidarcys, md). In another well, no longer in production, we observe tidal-cycle pressure variations indicating communication with the seabed and anomalous pressure build up that indicates influx of about 5 m3 (25 barrels) of seawater per day. Chemical and isotopic analysis confirms seawater mixing into the reservoir. Using an estimated fault volume of 6.3E+05 m3, we calculate a permeability of 1.9E-14 m2 (19 md) from the Darcy equation (Boles and Horner, 2003) for this well. These two permeability estimates, calculated by different methods, are remarkably similar and indicate that large fault conduits can have permeability of 10’s of md over kilometer length scales. Note: MCF= thousand cubic feet

  16. Electron and hole trap distribution and transport in titanium dioxide nanotubes

    NASA Astrophysics Data System (ADS)

    Mercado, Candy Cadang

    Titanium dioxide functions as an electron transport medium in dye sensitized solar cells. Nanotubular anatase titanium dioxide is expected to be a better photoanode because of the direct path of the electrons from injection to the working electrode due to the ordered nanotube walls. However, the performance of titanium dioxide nanotube-based solar cells lags behind the nanoparticulate-based. In this work, the crystallographic and defect properties of titanium dioxide nanotubes are examined with spectroscopic and materials characterization techniques in order to understand its electrical properties. Defects in the crystal structure lead to trap states within the bandgap which either assist or hinder electron collection. Shallow traps, those within the range of kT from the conduction band help in increasing the density of states thus increasing conduction. Deep traps capture the electrons and increase the probability of recombination with the oxidized form of the electrolyte. To probe these intra-band states, intra-band photoluminescence spectroscopy was used. Nanotube photoluminescence consists of three types of emission at approximate peak positions of 425 nm (2.9 eV), 550 nm (2.2 eV), and 650 nm (1.9 eV), which are attributed to recombination of the following nature: exciton, mobile electrons to trapped holes, and mobile holes to trapped electrons, respectively. These defects are similar to that found in nanoparticulate anatase. Although the nature of the defects is the same, the emission intensity in nanotubes is lower than nanoparticles. However, comparison with single nanotube photoluminescence revealed that quenching in "bulk" array is caused by significant charge transport in the lateral direction (between neighboring nanotubes). The orientation of the nanotube wall length is parallel (with slight angular deviations) to the c-axis direction of the unit cell as shown by electron backscatter diffraction. This leads to exposed planes of (100), (110), and (101). Single nanotube photoluminescence in epi-illumination showed that the walls are uniform with respect to defect densities. However, a focused laser beam gave satellite emissions from the ends of a nanotube that show recombination of mobile electrons with trapped holes giving a visual indication of electron transport in the nanostructure.

  17. Modulation of neuronal activity in dorsal column nuclei by upper cervical spinal cord stimulation in rats

    PubMed Central

    Qin, Chao; Yang, Xiaoli; Wu, Mingyuan; Farber, Jay P.; Linderoth, Bengt; Foreman, Robert D.

    2009-01-01

    Clinical human and animal studies show that upper cervical spinal cord stimulation (cSCS) has beneficial effects in treatment of some cerebral disorders, including those due to deficient cerebral circulation. However, the underlying mechanisms and neural pathways activated by cSCS using clinical parameters remain unclear. We have shown that a cSCS-induced increase in cerebral blood flow is mediated via rostral spinal dorsal column fibers implying that the dorsal column nuclei (DCNs) are involved. The aim of this study was to examine how cSCS modulated neuronal activity of DCNs.. A spring-loaded unipolar ball electrode was placed on the left dorsal column at cervical (C2) spinal cord in pentobarbital anesthetized, ventilated and paralyzed male rats. Stimulation with frequencies of 1, 10, 20, 50 Hz (0.2 ms, 10 s) and an intensity of 90% of motor threshold was applied. Extracellular potentials of single neurons in DCNs were recorded and examined for effects of cSCS. In total, 109 neurons in DCNs were isolated and tested for effects of cSCS. Out of these, 56 neurons were recorded from the cuneate nucleus and 53 from the gracile nucleus. Mechanical somatic stimuli altered activity of 87/109 (83.2%) examined neurons. Of the neurons receiving somatic input, 62 were classified as low-threshold and 25 as wide dynamic range. The cSCS at 1 Hz changed the activity of 96/109 (88.1%) of the neurons. Neuronal responses to cSCS exhibited multiple patterns of excitation and/or inhibition: excitation (E, n=21), inhibition (I, n=19), E-I (n=37), I-E (n=8) and E-I-E (n=11). Furthermore, cSCS with high-frequency (50 Hz) altered the activity of 92.7% (51/55) of tested neurons, including 30 E, 24 I, and 2 I-E responses to cSCS. These data suggested that cSCS significantly modulates neuronal activity in dorsal column nuclei. These nuclei might serve as a neural relay for cSCS-induced effects on cerebral dysfunction and diseases. PMID:19665525

  18. F-box/LRR-repeat protein 7 is genetically associated with Alzheimer’s disease

    PubMed Central

    Tosto, Giuseppe; Fu, Hongjun; Vardarajan, Badri N; Lee, Joseph H; Cheng, Rong; Reyes-Dumeyer, Dolly; Lantigua, Rafael; Medrano, Martin; Jimenez-Velazquez, Ivonne Z; Elkind, Mitchell S V; Wright, Clinton B; Sacco, Ralph L; Pericak-Vance, Margaret; Farrer, Lindsay; Rogaeva, Ekaterina; St George-Hyslop, Peter; Reitz, Christiane; Mayeux, Richard

    2015-01-01

    Objective In the context of late-onset Alzheimer’s disease (LOAD) over 20 genes have been identified but, aside APOE, all show small effect sizes, leaving a large part of the genetic component unexplained. Admixed populations, such as Caribbean Hispanics, can provide a valuable contribution because of their unique genetic profile and higher incidence of the disease. We aimed to identify novel loci associated with LOAD. Methods About 4514 unrelated Caribbean Hispanics (2451 cases and 2063 controls) were selected for genome-wide association analysis. Significant loci were further tested in the expanded cohort that also included related family members (n = 5300). Two AD-like transgenic mice models (J20 and rTg4510) were used to study gene expression. Independent data sets of non-Hispanic Whites and African Americans were used to further validate findings, along with publicly available brain expression data sets. Results A novel locus, rs75002042 in FBXL7 (5p15.1), was found genome-wide significant in the case–control cohort (odd ratio [OR] = 0.61, P = 6.19E-09) and confirmed in the related members cohorts (OR = 0.63, P = 4.7E-08). Fbxl7 protein was overexpressed in both AD-like transgenic mice compared to wild-type littermates. Publicly available microarray studies also showed significant overexpression of Fbxl7 in LOAD brains compared to nondemented controls. single-nucleotide polymorphism (SNP) rs75002042 was in complete linkage disequilibrium with other variants in two independent non-Hispanic White and African American data sets (0.0005 < P < 0.02) used for replication. Interpretation FBXL7, encodes a subcellular protein involved in phosphorylation-dependent ubiquitination processes and displays proapoptotic activity. F-box proteins also modulate inflammation and innate immunity, which may be important in LOAD pathogenesis. Further investigations are needed to validate and understand its role in this and other populations. PMID:26339675

  19. High density Schottky barrier IRCCD sensors for SWIR applications at intermediate temperature

    NASA Technical Reports Server (NTRS)

    Elabd, H.; Villani, T. S.; Tower, J. R.

    1982-01-01

    Monolithic 32 x 64 and 64 x 1:128 palladium silicide (Pd2Si) interline transfer infrared charge coupled devices (IRCCDs) sensitive in the 1 to 3.5 micron spectral band were developed. This silicon imager exhibits a low response nonuniformity of typically 0.2 to 1.6% rms, and was operated in the temperature range between 40 to 140 K. Spectral response measurements of test Pd2Si p-type Si devices yield quantum efficiencies of 7.9% at 1.25 microns, 5.6% at 1.65 microns 2.2% at 2.22 microns. Improvement in quantum efficiency is expected by optimizing the different structural parameters of the Pd2Si detectors. The spectral response of the Pd2Si detectors fit a modified Fowler emission model. The measured photo-electric barrier height for the Pd2Si detectors is 0.34 eV and the measured quantum efficiency coefficient, C1, is 19%/eV. The dark current level of Pd2Si Schottky barrier focal plane arrays (FPAs) is sufficiently low to enable operation at intermediate temperatures at TV frame rates. Typical dark current level measured at 120 K on the FPA is 2 nA/sq cm. The operating temperature of the Pd2Si FPA is compatible with passive cooler performance. In addition, high density Pd2Si Schottky barrier FPAs are manufactured with high yield and therefore represent an economical approach to short wavelength IR imaging. A Pd2Si Schottky barrier image sensor for push-broom multispectral imaging in the 1.25, 1.65, and 2.22 micron bands is being studied. The sensor will have two line arrays (dual band capability) of 512 detectors each, with 30 micron center-to-center detector spacing. The device will be suitable for chip-to-chip abutment, thus providing the capability to produce large, multiple chip focal planes with contiguous, in-line sensors.

  20. Hydraulic Shuttle Irradiation System (HSIS) Recently Installed in the Advanced Test Reactor (ATR)

    SciTech Connect

    A. Joseph Palmer; Gerry L. McCormick; Shannon J. Corrigan

    2010-06-01

    2010 International Congress on Advances in Nuclear Power Plants (ICAPP’10) ANS Annual Meeting Imbedded Topical San Diego, CA June 13 – 17, 2010 Hydraulic Shuttle Irradiation System (HSIS) Recently Installed in the Advanced Test Reactor (ATR) Author: A. Joseph Palmer, Mechanical Engineer, Irradiation Test Programs, 208-526-8700, Joe.Palmer@INL.gov Affiliation: Idaho National Laboratory P.O. Box 1625, MS-3840 Idaho Falls, ID 83415 INL/CON-10-17680 ABSTRACT Most test reactors are equipped with shuttle facilities (sometimes called rabbit tubes) whereby small capsules can be inserted into the reactor and retrieved during power operations. With the installation of Hydraulic Shuttle Irradiation System (HSIS) this capability has been restored to the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). The general design and operating principles of this system were patterned after the hydraulic rabbit at Oak Ridge National Laboratory’s (ORNL) High Flux Isotope Reactor (HFIR), which has operated successfully for many years. Using primary coolant as the motive medium the HSIS system is designed to simultaneously transport fourteen shuttle capsules, each 16 mm OD x 57 mm long, to and from the B-7 position of the reactor. The B-7 position is one of the higher flux positions in the reactor with typical thermal and fast (>1 Mev) fluxes of 2.8E+14 n/cm2/sec and 1.9E+14 n/cm2/sec respectively. The available space inside each shuttle is approximately 14 mm diameter x 50 mm long. The shuttle containers are made from titanium which was selected for its low neutron activation properties and durability. Shuttles can be irradiated for time periods ranging from a few minutes to several months. The Send and Receive Station (SRS) for the HSIS is located 2.5 m deep in the ATR canal which allows irradiated shuttles to be easily moved from the SRS to a wet loaded cask, or transport pig. The HSIS system first irradiated (empty) shuttles in September 2009 and has since completed a Readiness Assessment in November 2009. The HSIS is a key component of the ATR National Scientific User Facility (NSUF) operated by Battelle Energy Alliance, LLC and is available to a wide variety of university researchers for nuclear fuels and materials experiments as well as medical isotope research and production.

  1. Vibrational and optical properties of MoS2: From monolayer to bulk

    NASA Astrophysics Data System (ADS)

    Molina-Sánchez, Alejandro; Hummer, Kerstin; Wirtz, Ludger

    2015-12-01

    Molybdenum disulfide, MoS2, has recently gained considerable attention as a layered material where neighboring layers are only weakly interacting and can easily slide against each other. Therefore, mechanical exfoliation allows the fabrication of single and multi-layers and opens the possibility to generate atomically thin crystals with outstanding properties. In contrast to graphene, it has an optical gap of ~1.9 eV. This makes it a prominent candidate for transistor and opto-electronic applications. Single-layer MoS2 exhibits remarkably different physical properties compared to bulk MoS2 due to the absence of interlayer hybridization. For instance, while the band gap of bulk and multi-layer MoS2 is indirect, it becomes direct with decreasing number of layers. In this review, we analyze from a theoretical point of view the electronic, optical, and vibrational properties of single-layer, few-layer and bulk MoS2. In particular, we focus on the effects of spin-orbit interaction, number of layers, and applied tensile strain on the vibrational and optical properties. We examine the results obtained by different methodologies, mainly ab initio approaches. We also discuss which approximations are suitable for MoS2 and layered materials. The effect of external strain on the band gap of single-layer MoS2 and the crossover from indirect to direct band gap is investigated. We analyze the excitonic effects on the absorption spectra. The main features, such as the double peak at the absorption threshold and the high-energy exciton are presented. Furthermore, we report on the the phonon dispersion relations of single-layer, few-layer and bulk MoS2. Based on the latter, we explain the behavior of the Raman-active A1g and E2g1 modes as a function of the number of layers. Finally, we compare theoretical and experimental results of Raman, photoluminescence, and optical-absorption spectroscopy.

  2. [Evaluation of a new medium, eggplant (Solanum melongena) agar as a screening medium for Cryptococcus neoformans in environmental samples].

    PubMed

    Sengul, Mustafa; Ergin, Cağrı; Kartal, Tuğba

    2014-04-01

    Cryptococcus neofomans is an encapsulated yeast-like fungus that causes life-threatening infections, especially in immunosuppresive patients. C.neoformans infection is believed to be acquired via inhalation of aerosolized particles from the environment. Avian guano, decaying tree hollows and soil are the related known environmental niches. Brown pigmented yeast growth from the precursors in growth media is an important step for the identification and isolation of C.neoformans. Seeds of plants in nature are preferred owing to easy accessibility and low costs for the preparation of such media. Guizotia abysinicca (Niger seed) as Staib agar, Helianthus annus (Sunflower) as Pal's medium, Brassica nigra (Mustard) agar, tobacco agar, Mucuna pruriens (Velvet bean) seed agar, Perilla frutescens (Beefsteak plant) seed agar, Rubus fruticosus (Blackberry) agar and ground red hot pepper agar are pigment-based selective media for the differentiation of C.neoformans. The aim of this study was to observe the pigment production of C.neoformans in a new medium based on eggplant (Solanum melongena) and also to compare its performance with the simplified Staib, Pal's and tobacco agar for isolation from the environment. Three different eggplant-based medium (S.melongena Melanzaza viserba, S.melongena Pinstripe F1 and S.ovigerum Ivory F1) were included in the study. Pigment-forming eggplant medium, simplified Staib agar, Pal's agar and tobacco agar were used for the cultivation of the environmental swabbed samples from 19 Eucalyptus camaldulensis trunk hollows in continuous colonization region. While pigment formation were observed with S.melongena Melanzaza viserba and S.melongena Pinstripe F1 containing media, S.ovigerum Ivory F1 medium was found to be non-reactive. In colonization area (Gökova-Akyaka, Turkey), 11 (57.9%) out of 19 E.camaldulensis samples were positive with simplified Staib agar, Pal's agar and eggplant agar while 10 (52.6%) of them are positive with tobacco agar. C

  3. Comparison of single junction AlGaInP and GaInP solar cells grown by molecular beam epitaxy

    SciTech Connect

    Masuda, T; Tomasulo, S; Lang, JR; Lee, ML

    2015-03-07

    We have investigated similar to 2.0 eV (AlxGa1-x)(0.51)In0.49P and similar to 1.9 eV Ga0.51In0.49P single junction solar cells grown on both on-axis and misoriented GaAs substrates by molecular beam epitaxy (MBE). Although lattice-matched (AlxGa1-x)(0.51)In0.49P solar cells are highly attractive for space and concentrator photovoltaics, there have been few reports on the MBE growth of such cells. In this work, we demonstrate open circuit voltages (V-oc) ranging from 1.29 to 1.30 V for Ga0.51In0.49P cells, and 1.35-1.37 V for (AlxGa1-x)(0.51)In0.49P cells. Growth on misoriented substrates enabled the bandgap-voltage offset (W-oc = E-g/q - V-oc) of Ga0.51In0.49P cells to decrease from similar to 575 mV to similar to 565 mV, while that of (AlxGa1-x)(0.51)In0.49P cells remained nearly constant at 620 mV. The constant Woc as a function of substrate offcut for (AlxGa1-x)(0.51)In0.49P implies greater losses from non-radiative recombination compared with the Ga0.51In0.49P devices. In addition to larger Woc values, the (AlxGa1-x)(0.51)In0.49P cells exhibited significantly lower internal quantum efficiency (IQE) values than Ga0.51In0.49P cells due to recombination at the emitter/window layer interface. A thin emitter design is experimentally shown to be highly effective in improving IQE, particularly at short wavelengths. Our work shows that with further optimization of both cell structure and growth conditions, MBE-grown (AlxGa1-x)(0.51)In0.49P will be a promising wide-bandgap candidate material for high-efficiency, lattice-matched multi-junction solar cells. (C) 2015 AIP Publishing LLC.

  4. Relationship between Working Hours and Power of Attention, Memory, Fatigue, Depression and Self-Efficacy One Year after Diagnosis of Clinically Isolated Syndrome and Relapsing Remitting Multiple Sclerosis

    PubMed Central

    Jongen, Peter Joseph; Wesnes, Keith; van Geel, Björn; Pop, Paul; Schrijver, Hans; Visser, Leo H.; Gilhuis, H. Jacobus; Sinnige, Ludovicus G.; Brands, Augustina M.

    2014-01-01

    The role of cognitive domain dysfunction with respect to vocational changes in persons with Clinically Isolated Syndrome (CIS) and early Relapsing Remitting Multiple Sclerosis (eRRMS) is insufficiently known. We investigated thirty-three patients - 14 CIS, 19 eRRMS -, mean (standard deviation [SD]) time since diagnosis 13.5 (4.8) months and mean (SD) Expanded Disability Status Scale (EDSS) score 1.3 (1.1). Patients were assessed on the CDR System, a set of automated tests of cognitive function, which yielded scores for Power of Attention (ms), Continuity of Attention (#), Working Memory (SI), Episodic Memory (#) and Speed of Memory (ms). Work-related items and the confounding variables fatigue, depression, disease impact and self-efficacy, were assessed by self-report questionnaires. Patients had poorer Power of Attention compared to normative data (1187 [161.5] vs. 1070 [98.6]; P<0.0001) and slower Speed of Memory (4043 [830.6]) vs. 2937 [586.1]; P<0.0001). Power of Attention (Pearson r = −0.42; P<0.04), Working Memory (r = 0.42; P<0.04) and depression r = −0.41; P<0.05) correlated with number of days worked per week. Fatigue (r = −0.56; P<0.005), self-efficacy (r = 0.56; P<0.005) and disease impact (r = −0.46; P<0.05) correlated with number of hours worked per week. Persons who wished to work less had poorer Power of Attention (1247 vs. 1116 ms; P<0.02), those who wished to change job had poorer Episodic Memory (1.35 vs. 1.57; p<0.03). People who reduced working hours within 12 months after diagnosis had higher fatigue and disease impact, and lower self-efficacy. The findings of this pilot study indicate that one year after the diagnosis of CIS and RRMS Power of Attention and Speed of Memory are reduced, that Power of Attention and Memory are associated with a capability of working less hours, and that fatigue, depression and disease impact may negatively, and self-efficacy positively affect working hours. PMID:24787714

  5. Effect of the substituents on the photophysical, electrochemical and electroluminescence properties of OLED dopant Iridium bis(2-phenylbenzothiozolato- N,C2')(acetylacetonate)

    NASA Astrophysics Data System (ADS)

    Ivanov, P.; Tomova, R.; Petrova, P.

    2014-12-01

    The effect of two substituents: clorine and 1,3-diphenylpropane-1,3-dionate, placed on different position in the molecule of Iridium (III) bis(2-phenylbenzothiozolato-N,C2')- (acetylacetonate) (bt)2Ir(acac), on its electrochemical behaviour, photophysical and electroluminescence properties were investigated. Three complexes (bt)2Ir(acac), Iridium (III) bis[2-(4-chlorophenyl)benzothiazolato-N,C2']-acetylacetonate (Clbt)2Ir(acac), in which the Cl atom was introduced on the 4-position in the benzothiazole ring, and the new Iridium (Ill) bis[2 -phenylbenzothiazolato -N,C2'] -(1,3 -diphenylpropane-1,3 -dionate) (bt)2Ir(dbm), where ancillary acetylacetonate ligand was replaced by 1,3-diphenylpropane-1,3-dionate, were synthesized and characterised by 1H-NMR and elemental analysis. The HOMO/LUMO energy levels of the complexes were determined by cyclic voltammetry (CV) and their properties were established by UV-Visible and fluorescence spectroscopy. The application of (Clbt)2Ir(acac), (bt)2Ir(bsm) and (bt)2Ir(acac) as dopants in hole transporting layer (HTL) of Organic light- emitting diodes(OLEDs). It was found that with respect to the reference (bt)2Ir(acac): both LUMO and HOMO of the substituted complexes were shifted to more positive values accordingly with 0.23 and 0.19 eV for (Clbt)2Ir(acac) and 0.14 and 0.12 eV for (bt)2Ir(dbm). OLEDs doped with 1 w% of the complexes irradiated the warm white light with Commission internationale de l'eclairage (CIE) coordinates: 0.24;0.38 for (Clbt)2Ir(acac), 0.30;0.44 for (bt)2Ir(acac) and 0.28;0.46 for (bt)2Ir(dbm). Devices doped with 10 w% of all complexes irradiated in the yellow orange region of the spectrum.

  6. Ab initio continuum model for the influence of local stress on cross-slip of screw dislocations in fcc metals

    NASA Astrophysics Data System (ADS)

    Ramírez, Benjamín R.; Ghoniem, Nasr; Po, Giacomo

    2012-09-01

    We develop a model of cross-slip in face-centered cubic (fcc) metals based on an extension of the Peierls-Nabarro representation of the dislocation core. The dissociated core is described by a group of parametric fractional Volterra dislocations, subject to their mutual elastic interaction and a lattice-restoring force. The elastic interaction between them is computed from a nonsingular expression, while the lattice force is derived from the γ surface obtained directly from ab initio calculations. Using a network-based formulation of dislocation dynamics, the dislocation core structure is not restricted to be planar, and the activation energy is determined for a path where the core has three-dimensional equilibrium configurations. We show that the activation energy for cross-slip in Cu is 1.9eV when the core is represented by only two Shockley partials, while this value converges to 1.43eV when the core is distributed over a bundle of 20 Volterra partial fractional dislocations. The results of the model compare favorably with the experimental value of 1.15±0.37eV [J. Bonneville and B. Escaig, Acta Metall.AMETAR0001-616010.1016/0001-6160(79)90170-6 27, 1477 (1979)]. We also show that the cross-slip activation energy decreases significantly when the core is in a particular local stress field. Results are given for a representative uniform “Escaig” stress and for the nonuniform stress field at the head of a dislocation pileup. A local homogeneous stress field is found to result in a significant reduction of the cross-slip energy. Additionally, for a nonhomogeneous stress field at the head of a five-dislocation pileup compressed against a Lomer-Cottrell junction, the cross-slip energy is found to decrease to 0.62eV. The relatively low values of the activation energy in local stress fields predicted by the proposed model suggest that cross-slip events are energetically more favorable in strained fcc crystals.

  7. Dispersion of the linear and nonlinear optical susceptibilities of the CuAl(S{sub 1–x}Se{sub x})₂ mixed chaclcopyrite compounds

    SciTech Connect

    Reshak, A. H.; Brik, M. G.; Auluck, S.

    2014-09-14

    Based on the electronic band structure, we have calculated the dispersion of the linear and nonlinear optical susceptibilities for the mixed CuAl(S{sub 1–x}Se{sub x})₂ chaclcopyrite compounds with x=0.0, 0.25, 0.5, 0.75, and 1.0. Calculations are performed within the Perdew-Becke-Ernzerhof general gradient approximation. The investigated compounds possess a direct band gap of about 2.2 eV (CuAlS₂), 1.9 eV (CuAl(S₀.₇₅Se₀.₂₅)₂), 1.7 eV (CuAl(S₀.₅Se₀.₅)₂), 1.5 eV (CuAl(S₀.₂₅Se₀.₇₅)₂), and 1.4 eV (CuAlSe₂) which tuned to make them optically active for the optoelectronics and photovoltaic applications. These results confirm that substituting S by Se causes significant band gaps' reduction. The optical function's dispersion ε₂{sup xx}(ω) and ε₂{sup zz}(ω)/ε₂{sup xx}(ω), ε₂{sup yy}(ω), and ε₂{sup zz}(ω) was calculated and discussed in detail. To demonstrate the effect of substituting S by Se on the complex second-order nonlinear optical susceptibility tensors, we performed detailed calculations for the complex second-order nonlinear optical susceptibility tensors, which show that the neat parents compounds CuAlS₂ and CuAlSe₂ exhibit | χ₁₂₂²}(-2ω;ω;ω) | as the dominant component, while the mixed alloys exhibit | χ₁₁₁²(-2ω;ω;ω) | as the dominant component. The features of | χ₁₂₃²}(-2ω;ω;ω) | and | χ{sub 111}²}(-2ω;ω;ω) | spectra were analyzed on the basis of the absorptive part of the corresponding dielectric function ε₂(ω) as a function of both ω/2 and ω.

  8. Holocene climate variability, vegetation dynamics and fire regime in the central Pyrenees: the Basa de la Mora sequence (NE Spain)

    NASA Astrophysics Data System (ADS)

    Pérez-Sanz, A.; González-Sampériz, P.; Moreno, A.; Valero-Garcés, B.; Gil-Romera, G.; Rieradevall, M.; Tarrats, P.; Lasheras-Álvarez, L.; Morellón, M.; Belmonte, A.; Sancho, C.; Sevilla-Callejo, M.; Navas, A.

    2013-08-01

    High resolution multiproxy data (pollen, sedimentology, geochemistry, chironomids and charcoal) from the Basa de la Mora (BSM) lake sequence (42° 32' N, 0° 19' E, 1914 m a.s.l.) show marked climate variability in the central southern Pyrenees throughout the Holocene. A robust age model based on 15 AMS radiocarbon dates underpins the first precise reconstruction of rapid climate changes during the Holocene from this area. During the Early Holocene, increased winter snowpack and high snowmelt during summer, as a consequence of high seasonality, led to higher lake levels, a chironomid community dominated by non-lacustrine taxa (Orthocladiinae) related to higher inlet streams, and a forested landscape with intense run-off processes in the watershed. From 9.8 to 8.1 cal ka BP, climate instability is inferred from rapid and intense forest shifts and high fluctuation in surface run-off. Shifts among conifers and mesophytes reveal at least four short-lived dry events at 9.7, 9.3, 8.8 and 8.3 cal ka BP. Between 8.1 and 5.7 cal ka BP a stable climate with higher precipitation favoured highest lake levels and forest expansion, with spread of mesophytes, withdrawal of conifers and intensification of fires, coinciding with the Holocene Climate Optimum. At 5.7 cal ka BP a major change leading to drier conditions contributed to a regional decline in mesophytes, expansion of pines and junipers, and a significant lake level drop. Despite drier conditions, fire activity dropped as consequence of biomass reduction. Two arid intervals occurred between 2.9 and 2.4 cal ka BP and at 1.2-0.7 cal ka BP (800-1300 AD). The latter coincides with the Medieval Climate Anomaly and is one of the most arid phases of the Holocene in BSM sequence. Anthropogenic disturbances were small until 700 AD, when human pressure over landscape intensified, with Olea cultivation in the lowlands and significant deforestation in highlands. Colder and unfavourable weather conditions during the second part of the

  9. DOES GALACTIC MAGNETIC FIELD DISTURB THE CORRELATION OF THE HIGHEST ENERGY COSMIC RAYS WITH THEIR SOURCES?

    SciTech Connect

    Takami, Hajime; Sato, Katsuhiko

    2010-12-01

    The propagation trajectories of the highest energy cosmic rays (HECRs) are deflected by not only intergalactic magnetic field but also Galactic magnetic field (GMF). These magnetic fields can weaken the positive correlation between the arrival directions of HECRs and the positions of their sources. In order to explore the effect of GMF on the expected correlation, we simulate the arrival distribution of protons with energy above 6 x 10{sup 19} eV taking several GMF models into account, and then test the correlation between the protons and their sources assumed in the simulation. The dependence of the correlation signals on GMF models is also investigated. The correlation can be observed by accumulating {approx}200 protons in a half-hemisphere. The typical angular scale at which the positive signal of the correlation is maximized depends on the spiral component of the GMF model. That angular scale is {approx}5{sup 0} for bisymmetric spiral (BS) GMF models and {approx}7{sup 0} for axisymmetric spiral (AS) GMF models if the number density of HECR sources, n{sub s} , is {approx}10{sup -4} Mpc{sup -3}. An additional vertical (dipole) component of GMF affects these angular scales by 0.{sup 0}5-1{sup 0}. The difference between the correlation signal for the BS models and that for the AS models is prominent in the northern sky. The significance of the positive correlation depends on source distribution. The probability that the number of simulated HECR events correlating with sources is smaller than the number of random events correlating with the same sources by chance is much less than 10{sup -3} ({approx}3{sigma}) in almost all the source distributions with n{sub s} = 10{sup -4} Mpc{sup -3} for detection of under 200 protons, but {approx}10% of source distributions predict a chance probability more than 10{sup -3} in the AS GMF model. In addition, we also briefly discuss the effect of GMF for heavy-nuclei-dominated composition.

  10. Mitigation of Water Stress on Apple Trees under Rotational Irrigation Conditions by Increasing the Application Rate of Organic Fertilizers to Sandy Soils

    NASA Astrophysics Data System (ADS)

    Hamed, Lamy Mamdoh Mohamed; Ramadan Eid, Abdelraouf; Mohsmed Rabie Abdellatif Abdelaziz, Adel; Fathy Abdelsalam Essa, El-Sayed

    2016-04-01

    Egypt, as part of Mediterranean regions, is characterized by irregular and low rainfall amount which varies between (30-150 mm.year‑1), and characterized also by high temperature which increase the rate of evapotranspiration from the cultivated soil. On the other hand, New reclaimed soils are mostly occupies around 84 % of total area of Egypt, which is mainly sandy soils. These soils generally characterized by low water capacity holding, soil organic matter, and weak in nutrients retention. Under these conditions which have a great influence on crop production, there is a great needing to increase the crop water use efficiency and increasing of nutrient retention in sandy soils. In this context, two field experiments were carried out on sand soil located in north Cairo-Egypt at the experimental farm of National Research Center, El-NUBARIA, (latitude 30° 30' N, and longitude 30° 19' E). The effect of compost rates on soil hydraulic characteristics, fruit yields, quality traits, and water use efficiency and productivity of apple tree (Apple Anna Cultivar), was studied under deficit irrigation conditions. Four rates of compost [I1: control, I2: 12 ton.ha‑1., I3: 24 ton.ha‑1., I4: 36 ton.ha‑1. and I5:48 ton.ha‑1.] were applied under irrigation frequencies of (IF1 :once per week; IF2 :twice per week, IF3 :three times per week). The obtained results indicated that by increasing the application rate of compost, the available water capacity and saturated water content of sandy soil have been enhanced. In the same time, the fruit yield, quality traits and water productivity were increased by increasing the application rate of compost. It is worthy to mention that the I5IF3 treatment gave the highest values of fruit yield, quality traits and water productivity, whereas I1IF1 treatment gave the lowest values of all the above mentioned variables. As result, for apple cultivation in El-NUBARIA region, the recommended rate of compost is 48 ton.ha‑1 and irrigation

  11. Recovery of bacteria from broiler carcass respiratory tracts before and after immersion scalding.

    PubMed

    Buhr, R J; Berrang, M E; Cason, J A; Bourassa, D V

    2005-11-01

    Occlusion of the trachea and decapitation were compared with a conventional unilateral neck cut for effects on bacteria entering into the respiratory tract of broiler carcasses during scalding. In experiment 1, the trachea was occluded prior to the carcass entering the scalder to determine if bacterial recovery from the respiratory tract could be diminished. The first carcass was removed at the end of bleeding, and a plastic cable tie was placed around the neck of a second carcass and tightened to occlude the trachea. After proceeding through the triple-tank immersion scalder, the second carcass (trachea occluded) was removed, and a third carcass (without the trachea occluded during scalding) was removed. In experiment 2, after being stunned, carcasses were unilaterally bled or decapitated. Unilaterally bled and decapitated carcasses were removed at the end of bleeding and after scalding. In both experiments, trachea were cannulated, and respiratory tract rinses were collected. For experiment 1, the numbers of bacteria recovered (log10 cfu/mL of rinse) from prescald nonoccluded carcass respiratory tract rinses were 2.5 Escherichia coli, 2.6 coliforms, and 3.2 total aerobes. Respiratory tract rinses from carcasses sampled postscald (without occluding the trachea) had higher bacteria numbers at 4.6 E. coli, 5.0 coliforms, and 5.4 total aerobes. Respiratory tract rinses from carcasses with the trachea occluded prior to scalding had the lowest number of bacteria at 1.9 E. coli, 2.3 coliforms, and 2.7 total aerobes. In experiment 2, the numbers of bacteria recovered from respiratory tract rinses of unilaterally bled or decapitated carcasses did not differ prescald or postscald, although all postscald values were higher (P < 0.05). Results confirmed that bacteria numbers increased within the respiratory tract during immersion scalding, the increase could have been prevented by occluding the trachea prior to scalding, and decapitation did not alter the number of bacteria recovered from respiratory tract rinses prior to or following immersion scalding. PMID:16463975

  12. Fracture hydraulic conductivity in the Mexico City clayey aquitard: Field piezometer rising-head tests

    NASA Astrophysics Data System (ADS)

    Vargas, Carlos; Ortega-Guerrero, Adrián

    A regional lacustrine aquitard covers the main aquifer of the metropolitan area of Mexico City. The aquitard's hydraulic conductivity (K') is fundamental for evaluating the natural protection of the aquifer against a variety of contaminants present on the surface and its hydraulic response. This study analyzes the distribution and variation of K' in the plains of Chalco, Texcoco and Mexico City (three of the six former lakes that existed in the Basin of Mexico), on the basis of 225 field-permeability tests, in nests of existing piezometers located at depths of 2-85 m. Tests were interpreted using the Hvorslev method and some by the Bouwer-Rice method. Results indicate that the distribution of K' fits log-Gaussian regression models. Dominant frequencies for K' in the Chalco and Texcoco plains range between 1E-09 and 1E-08 m/s, with similar population means of 1.19E-09 and 1.7E-09 m/s, respectively, which are one to two orders of magnitude higher than the matrix conductivity. In the Mexico City Plain the population mean is near by one order of magnitude lower; K'=2.6E-10 m/s. The contrast between the measured K' and that of the matrix is attributed to the presence of fractures in the upper 25-40 m, which is consistent with the findings of previous studies on solute migration in the aquitard. Un imperméable régional d'origine lacustre recouvre le principal aquifère de la zone urbaine de la ville de Mexico. La conductivité hydraulique K' de cet imperméable est fondamentale pour évaluer la protection naturelle de l'aquifère, contre les différents contaminants présents en surface, et sa réponse hydraulique. Cette étude analyse et les variations de K' dans les plaines de Chalco, Texcoco et Mexico (trois des six anciens lacs qui existaient dans le Bassin de Mexico), sur la base de 225 essais de perméabilité sur le terrain, réalisés en grappes dans des piézomètres existants entre 2 et 85 m de profondeur. Les essais ont été interprétés avec la m

  13. SPECIAL ANALYSIS AIR PATHWAY MODELING OF E-AREA LOW-LEVEL WASTE FACILITY

    SciTech Connect

    Hiergesell, R.; Taylor, G.

    2011-08-30

    This Special Analysis (SA) was initiated to address a concern expressed by the Department of Energy's Low Level Waste Disposal Facility Federal Review Group (LFRG) Review Team during their review of the 2008 E-Area Performance Assessment (PA) (WSRC, 2008). Their concern was the potential for overlapping of atmospheric plumes, emanating from the soil surface above SRS LLW disposal facilities within the E-Area, to contribute to the dose received by a member of the public during the Institutional Control (IC) period. The implication of this concern was that the dose to the maximally-exposed individual (MEI) located at the SRS boundary might be underestimated during this time interval. To address this concern a re-analysis of the atmospheric pathway releases from E-Area was required. In the process of developing a new atmospheric release model (ARM) capable of addressing the LFRG plume overlap concern, it became obvious that new and better atmospheric pathway disposal limits should be developed for each of the E-Area disposal facilities using the new ARM. The scope of the SA was therefore expanded to include the generation of these new limits. The initial work conducted in this SA was to develop a new ARM using the GoldSim{reg_sign} program (GTG, 2009). The model simulates the subsurface vapor diffusion of volatile radionuclides as they release from E-Area disposal facility waste zones and migrate to the land surface. In the process of this work, many new features, including several new physical and chemical transport mechanisms, were incorporated into the model. One of the most important improvements was to incorporate a mechanism to partition volatile contaminants across the water-air interface within the partially saturated pore space of the engineered and natural materials through which vapor phase transport occurs. A second mechanism that was equally important was to incorporate a maximum concentration of 1.9E-07 Ci/m{sup 3} of {sup 14}CO{sub 2} in the air-filled pores of cementitious materials. The ARM also combines the individual transport models constructed for each E-Area disposal facility into a single model, and was ultimately used to analyze the LFRG concern regarding the potential for atmospheric plume overlap at the SRS boundary during the IC period. To evaluate the plume overlap issue, a conservative approach was adopted whereby the MEI at the SRS boundary was exposed to the releases from all E-Area disposal facilities simultaneously. This is equivalent to a 100% overlap of all atmospheric plumes emanating from E-Area. Should the dose received from this level of atmospheric plume overlap still fall below the permissible exposure level of 10 mrem/yr, then the LFRG concern would be alleviated. The structuring of the ARM enables this evaluation to be easily performed. During the IC period, the peak of the 'total plume overlap dose' was computed to be 1.9E-05 mrem/yr, which is five orders of magnitude lower than the 10 mrem/yr PA performance objective for the atmospheric release pathway. The main conclusion of this study is that for atmospheric releases from the E-Area disposal facilities, plume overlap does not cause the total dose to the MEI at the SRS boundary during the IC to exceed the Performance Assessment (PA) performance objective. Additionally, the potential for plume overlap was assessed in the post-Institutional Control period. Atmospheric plume overlap is less likely to occur during this period but conceivably could occur if the prevailing wind direction shifted so as to pass directly over all EArea disposal facilities and transport airborne radionuclides to the MEI at the 100 m point of compliance (POC). This concern was also demonstrated of little concern, as the maximum plume overlap dose was found to be 1.45E+00 mrem/yr (or {approx}15% of the performance measure) during this period and under these unlikely conditions.

  14. Two VLT 8.2-m Unit Telescopes in Action

    NASA Astrophysics Data System (ADS)

    1999-04-01

    454 pix - 86k] [Normal - JPEG: 800 x 907 pix - 301k] [High-Res - JPEG: 978 x 1109 pix - 282k] Caption to PR Photo 19c/99 : Somewhat further out in space, and right on the border between the southern constellations Hydra and Centaurus lies this knotty spiral galaxy, IC 4248 ; the distance is about 210 million light-years. It was imaged with KUEYEN on March 28, 1999, with the same filters and exposure times as used for Photo 19b/99. The image quality is 0.75 arcsec and the field is 90 x 90 arcsec 2. North is up and East is left. Caption to PR Photo 19d/99 : This is a close-up view of the double galaxy NGC 5090 (right) and NGC 5091 (left), in the southern constellation Centaurus. The first is a typical S0 galaxy with a bright diffuse centre, surrounded by a fainter envelope of stars (not resolved in this picture). However, some of the starlike objects seen in this region may be globular clusters (or dwarf galaxies) in orbit around NGC 5090. The other galaxy is of type Sa (the spiral structure is more developed) and is seen at a steep angle. The three-colour composite is based on frames obtained with KUEYEN on March 29, 1999, with the same filters and exposure times as used for Photo 19b/99. The image quality is 0.7 arcsec and the field is 90 x 90 arcsec 2. North is up and East is left. ( Note inserted on April 26: The original caption text identified the second galaxy as NGC 5090B - this error has now been corrected. ESO PR Photo 19e/99 ESO PR Photo 19e/99 [Preview - JPEG: 400 x 441 pix - 282k] [Normal - JPEG: 800 x 882 pix - 966k] [High-Res - JPEG: 3000 x 3307 pix - 6,4M] Caption to PR Photo 19e/99 : Wide-angle photo of the second 8.2-m VLT Unit Telescope, KUEYEN , obtained on March 10, 1999, with the main mirror and its cell in place at the bottom of the telescope structure. The Test Camera with which the astronomical images above were made, is positioned at the Cassegrain focus, inside this mirror cell. The Paranal Inauguration on March 5, 1999, took place under this

  15. Natural bog pine ecosystem in southern Germany is a steady and robust sink of CO2 but a minor source of CH4

    NASA Astrophysics Data System (ADS)

    Hommeltenberg, Janina; Schmid, Hans Peter; Droesler, Matthias; Werle, Peter

    2013-04-01

    Natural peatland ecosystems sequester carbon dioxide. They do this slowly but steadily, but also emit methane in small rates. Thus peatlands have both positive and negative greenhouse gas balance impacts on the climate system due to their influence on atmospheric CO2 and CH4 concentration. We present data of net ecosystem CO2 exchange (NEE) of almost three years (July 2010 to March 2013) and of methane fluxes over a period of nine months (July 2012 to March 2013), measured by eddy covariance technique in the bog forest "Schechenfilz". The site (47°48' N; 11°19' E, 590 m a.s.l.) is an ICOS-ecosystems associate site, located in the pre-alpine region of southern Germany, where a natural Pinus mugo rotundata forest grows on an undisturbed, almost 6 m thick peat layer. The slow growing bog pines and their low rates of carbon sequestration, in combination with high water table and thus low availability of oxygen, lead to low carbon dioxide fluxes. Photosynthesis as well as soil respiration are considerably attenuated compared to upland sites. Additionally, the high soil water content is damping the impact of dry and hot periods on CO2 exchange. Thus the CO2 balance is very robust to changing environmental parameters. While the CO2 exchange is clearly related to soil temperature and photosynthetic active radiation, we have not yet identified a parameter that governs variations in methane exchange. Various environmental parameters appear to be related to methane emissions (including soil moisture, soil and air temperature and wind direction), but the scatter with respect to half hourly methane fluxes is too large to be useful for gap modeling. Analysis of daily averages reduces the scatter, but since methane exchange exhibits considerable daily variation, daily averages are not useful to fill data gaps of half hourly fluxes. In consequence, as the daily course is the summary result of all environmental parameters having influence on the methane exchange at the half

  16. Magnesium Vacancy Segregation and Fast Pipe Diffusion for the ½<110>{110} Edge Dislocation in MgO

    NASA Astrophysics Data System (ADS)

    Walker, A. M.; Zhang, F.; Wright, K.; Gale, J. D.

    2009-12-01

    The movement of point defects in minerals plays a key role in determining their rheological properties, both by permitting diffusional creep and by allowing recovery by dislocation climb. Point defect diffusion can also control the kinetics of phase transitions and grain growth, and can determine the rate of chemical equilibration between phases. Because of this, and the difficulties associated with experimental studies of diffusion, the simulation of point defect formation and migration has been a subject of considerable interest in computational mineral physics. So far, studies have concentrated on point defects moving through otherwise perfect crystals. In this work we examine the behavior of magnesium vacancies close to the core of an edge dislocation in MgO and find that the dislocation dramatically changes the behavior of the point defect. An atomic scale model of the ½<110>{110} edge dislocation in MgO was constructed by applying the anisotropic linear elastic displacement field to the crystal structure and subsequently minimizing the energy of the crystal close to the dislocation core using a parameterized potential model. This process yielded the structure of an isolated edge dislocation in an otherwise perfect crystal. The energy cost associated with introducing magnesium vacancies around the dislocation was then mapped and compared to the formation energy of an isolated magnesium vacancy in bulk MgO. We find that the formation energy of magnesium vacancies around the dislocation mirrors the elastic strain field. Above the dislocation line σxx and σyy are negative and the strain field is compressional. Atoms are squeezed together to make room for the extra half plane effectively increasing the pressure in this region. Below the dislocation line σxx and σyy are positive and the strain field is dilatational. Planes of atoms are pulled apart to avoid a discontinuity across the glide plane and the effective pressure is decreased. In the region with a compressional strain field the vacancies become less stable than those in perfect MgO. In contrast, the region with a dilatational strain field hosts vacancies which are stabilized compared to the perfect crystal. This is in agreement with the previously observed tendency for increasing pressure to decrease the stability of vacancies in MgO. The most stable position for a magnesium vacancy was found to be 1.7 eV more stable than the vacancy in the bulk crystal, suggesting that vacancies will strongly partition to dislocations in MgO. Finally, the energy profile traced out by a vacancy moving through the bulk crystal was compared with that experienced by a vacancy moving along the dislocation core. A low energy pathway for vacancy migration along the dislocation line was found with a migration energy of 1.6 eV compared with a migration energy in the perfect crystal of 1.9 eV. This shows that vacancies segregated to the dislocation line will be significantly more mobile than vacancies in the perfect crystal. Dislocations will act as pipes, allowing material to be rapidly transported through crystals of MgO.

  17. Low-dielectric-constant fluorinated diamond-like carbon thin films by plasma-enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Yi, Jeong Woo

    Fluorinated amorphous carbon (a-C:F) thin films are developed for a low dielectric constant interlayer dielectric material from hexafluorobenze (C 6F6) or 1,1,1,2-tetrafluoroethane (FCH2CF 4) as the source gas and argon as the diluent gas in an asymmetric capacitively coupled rf (radio frequency) plasma reactor and an inductively coupled plasma reactor. Effects of input rf power, fluorination, applied bias voltage and post annealing on the properties of a-C:F films are investigated. For depositing a-C:F films from highly diluted C6F6 (3%) and argon (97%) in the capacitively rf plasma reactor at 150 mTorr, the dielectric constant of the film increases from 2.0 to 2.8 as the rf power is increased from 10 W to 70 W, while the optical energy gap decreases from 2.6 eV to 1.9 eV and the transparency in a ultra-violet range is degraded. At input power of 100 W, the deposited film exhibits high residual stress of 40 MPa and easily peeled off by a Scotch tape test. This is due to high self-bias voltage (-230 V) developed at the substrate holder during deposition. When depositing amorphous carbon films from tetrafluoroethane (TFE) and methane in the capacitively coupled plasma reactor, the incorporation of fluorine in the film is increased with increasing TFE fraction in the feed gas mixture. The dielectric constant of the a-C:F film deposited from pure TFE is as low as 2.3, but the film exhibits poor thermal stability while a-C:H (diamond-like carbon) film deposited from pure methane has a dielectric constant of 3.8 and shows good thermal stability up to 400°C. As the TFE content in the feed is increased, the dielectric constant and the refractive index decrease while the transparency of the film is enhanced significantly. When depositing a-C:F films from C6F6 (4 sccm) and Ar (5 sccm) in the inductively coupled rf plasma reactor, the bias voltage (from a separate 100 KHz source) applied to the substrate holder affects the film properties significantly. As the negative bias voltage is increased from 0 V to 200 V, the dielectric constant of the film increases from 2.1 to 2.6, and the degree of graphitization in the film is enhanced. When no bias voltage is applied, interface traps are formed between the film and the silicon substrate at a significant level, whereas a high bias voltage of -200 V degrades the film quality---the film exhibits high water absorption and high leakage current. Post annealing in N2 or H2 enhances the electrical properties of a-C:F films. At annealing temperatures greater than 300°C, the films exhibit few defects and high degree of crosslinking. Annealing in H2 environment is effective in decreasing the interface traps and the charge density in the film. Annealing in N2 environment is effective in eliminating the water absorption by the film is prevented and in enhancing the adhesion of the film to glass substrates. To deposit low dielectric constant fluorinated amorphous carbon thin films, low rf powers should used in capacitively coupled rf plasma reactors or low bias voltages should be used in inductively coupled plasma reactors. Post annealing at 400°C in a H2 environment is recommended for improving film quality.

  18. Pliocene East Antarctic Ice Sheet Retreat in the Wilkes Subglacial Basin

    NASA Astrophysics Data System (ADS)

    Cook, C.; van de Flierdt, T.; Williams, T.; Hemming, S. R.; Pierce, E. L.; Iwai, M.; Kobayashi, M.; Jimenez-Espejo, F.; Escutia, C.; González, J.; Patterson, M. O; Mckay, R. M.; Passchier, S.; Tauxe, L.; Sugisaki, S.; Bohaty, S. M.; Riesselman, C. R.; Sangiorgi, F.; Brinkhuis, H.

    2012-12-01

    Polar ice sheets are an important component of the climate system, affecting global sea level, ocean circulation and heat transport, marine productivity, and albedo. However, there is considerable uncertainty in the response of the polar ice caps to predicted future warming. Warm intervals during the Pliocene Epoch (5.33-2.58 Ma) may provide insight on the sensitivity of ice sheets when atmospheric carbon dioxide levels were similar to today and temperatures were elevated by a few degrees Celsius. Global sea level during this time has been estimated to lie about 20m above modern, requiring not only Greenland and West Antarctica, but also the large East Antarctic ice sheet (EAIS) to have lost mass. Direct evidence for ice retreat around East Antarctica is, however, sparse. Here we present results of neodymium (Nd) and strontium (Sr) isotope analyses of detrital clay and silt-sized sediments from Integrated Ocean Drilling Program Leg 318 Site U1361 (64°24.57'S, 143°53.19'E), drilled offshore of the Wilkes Subglacial Basin, where large areas of the EAIS lie below sea level. Early Pliocene (5.33 to 3.3 Ma) detrital sediments from this location reveal two distinct endmembers. The first endmember is defined by epsilon Nd values of -11 to -14.5 and Sr isotopic compositions of 0.720 to 0.730, and the second endmember is characterized by more radiogenic values of -5.9 to -9.5 and 0.713 to 0.719, respectively. While the first endmember is consistent with siliciclastic material sourced from Early Paleozoic bedrocks exposed in Oates Land and the western region of Northern Victoria Land to the east of the study site, the second endmember requires a significant contribution (95-70%) from the Jurassic-Triassic Ferrar Large Igneous Province (FLIP), which today is only regionally exposed in volumetrically significant quantities in the Transantarctic Mountains. For this area to be an important source to IODP Site U1361 sediments, significant retreat of outlet glaciers and collapse

  19. Modeling the spatial differentiation in cloud-to-ground lightning: A case study in Atlanta, Georgia, USA

    NASA Astrophysics Data System (ADS)

    Strikas, Ona

    likely to occur between 15 and 33microg/m 3, but the data has significant flash frequency variability even within these PM10 levels. Immediate proximity to highways proves not to be a significant variable in modeling flash frequency at any resolution. Coal plant proximity has the potential to enhance CG flash frequency, but the inherent variability in frequency precludes a strong p-value compared to randomly generated areas. However, if the data is subset by flashes/day over 500, then the areas close to coal plants have significantly more lightning (p=2.19e-5). Using a subset of the twenty-five highest frequency flash days in three equal area study areas (Haralson and Polk Counties representing rural, Cobb County representing developed and upwind of Atlanta, and Gwinnett County representing downwind and developed) Mann-Whitney tests are completed to determine if NWS severe thunderstorm storms are significantly different in CG flash frequency. In each study area, the NWS severe thunderstorms are not significantly different in flash frequency than non-severe storms. This analysis also suggests spatial tendencies of high frequency storms in each area. This multi-scale analysis also suggests that when examining CG lightning, more than one scale of examination should be used. Some processes of lightning amplification appear to occur at very local scales (500m), whereas others are coarser (up to 8km). There appears to be no goldilocks scale of analysis for CG lightning. However, if only one resolution is to be used, 2km is recommended.

  20. Air-snow transfer of nitrate on the East Antarctic Plateau - Part 2: An isotopic model for the interpretation of deep ice-core records

    NASA Astrophysics Data System (ADS)

    Erbland, J.; Savarino, J.; Morin, S.; France, J. L.; Frey, M. M.; King, M. D.

    2015-10-01

    Unraveling the modern budget of reactive nitrogen on the Antarctic Plateau is critical for the interpretation of ice-core records of nitrate. This requires accounting for nitrate recycling processes occurring in near-surface snow and the overlying atmospheric boundary layer. Not only concentration measurements but also isotopic ratios of nitrogen and oxygen in nitrate provide constraints on the processes at play. However, due to the large number of intertwined chemical and physical phenomena involved, numerical modeling is required to test hypotheses in a quantitative manner. Here we introduce the model TRANSITS (TRansfer of Atmospheric Nitrate Stable Isotopes To the Snow), a novel conceptual, multi-layer and one-dimensional model representing the impact of processes operating on nitrate at the air-snow interface on the East Antarctic Plateau, in terms of concentrations (mass fraction) and nitrogen (δ15N) and oxygen isotopic composition (17O excess, Δ17O) in nitrate. At the air-snow interface at Dome C (DC; 75° 06' S, 123° 19' E), the model reproduces well the values of δ15N in atmospheric and surface snow (skin layer) nitrate as well as in the δ15N profile in DC snow, including the observed extraordinary high positive values (around +300 ‰) below 2 cm. The model also captures the observed variability in nitrate mass fraction in the snow. While oxygen data are qualitatively reproduced at the air-snow interface at DC and in East Antarctica, the simulated Δ17O values underestimate the observed Δ17O values by several per mill. This is explained by the simplifications made in the description of the atmospheric cycling and oxidation of NO2 as well as by our lack of understanding of the NOx chemistry at Dome C. The model reproduces well the sensitivity of δ15N, Δ17O and the apparent fractionation constants (15ϵapp, 17Eapp) to the snow accumulation rate. Building on this development, we propose a framework for the interpretation of nitrate records