Sustained blood glutamate scavenging enhances protection in ischemic stroke

Stroke is a major cause of morbidity, mortality, and disability. During ischemic stroke, a marked and prolonged rise of glutamate concentration in the brain causes neuronal cell death. This study explores the protective effect of a bioconjugate form of glutamate oxaloacetate transaminase (hrGOT), which catalyzes the depletion of blood glutamate in the bloodstream for ~6 days following a single administration. When treated with this bioconjugate, a significant reduction of the infarct volume and a better retention of sensorimotor function was observed for ischemic rats compared to those treated with saline. Moreover, the equivalent dose of native hrGOT yielded similar results to the saline treated group for some tests. Targeting the bioconjugate to the blood-brain-barrier did not improve its performance. The data suggest that the bioconjugates draw glutamate out of the brain by displacing homeostasis between the different glutamate pools of the body

Albedo and atmospheric constraints of dwarf planet Makemake from a stellar occultation

Pluto and Eris are icy dwarf planets with nearly identical sizes, comparable densities and similar surface compositions as revealed by spectroscopic studies1, 2. Pluto possesses an atmosphere whereas Eris does not; the difference probably arises from their differing distances from the Sun, and explains their different albedos3. Makemake is another icy dwarf planet with a spectrum similar to Eris and Pluto4, and is currently at a distance to the Sun intermediate between the two. Although Makemake’s size (1,420 ± 60 km) and albedo are roughly known5, 6, there has been no constraint on its density and there were expectations that it could have a Pluto-like atmosphere4, 7, 8. Here we report the results from a stellar occultation by Makemake on 2011 April 23. Our preferred solution that fits the occultation chords corresponds to a body with projected axes of 1,430 ± 9 km (1σ) and 1,502 ± 45 km, implying a V-band geometric albedo pV = 0.77 ± 0.03. This albedo is larger than that of Pluto, but smaller than that of Eris. The disappearances and reappearances of the star were abrupt, showing that Makemake has no global Pluto-like atmosphere at an upper limit of 4–12 nanobar (1σ) for the surface pressure, although a localized atmosphere is possible. A density of 1.7 ± 0.3 g cm−3 is inferred from the data

Charon's size and an upper limit on its atmosphere from a stellar occultation

Pluto and its satellite, Charon (discovered in 1978; ref. 1), appear to form a double planet, rather than a hierarchical planet/satellite couple. Charon is about half Pluto's size and about one-eighth its mass. The precise radii of Pluto and Charon have remained uncertain, leading to large uncertainties on their densities2. Although stellar occultations by Charon are in principle a powerful way of measuring its size, they are rare, as the satellite subtends less than 0.3 microradians (0.06 arcsec) on the sky. One occultation (in 1980) yielded a lower limit of 600 km for the satellite's radius 3, which was later refined to 601.5 km (ref. 4). Here we report observations from a multi-station stellar occultation by Charon, which we use to derive a radius, RC = 603.6 ± 1.4 km (1σ), and a density of ρ = 1.71 ± 0.08 g cm-3. This occultation also provides upper limits of 110 and 15 (3σ) nanobar for an atmosphere around Charon, assuming respectively a pure nitrogen or pure methane atmosphere. © 2006 Nature Publishing Group.Fil: Sicardy, B.. Universite Pierre et Marie Curie; Francia. Gepi - Galaxies, Etoiles, Physique, Instrumentation;Fil: Bellucci, A.. Gepi - Galaxies, Etoiles, Physique, Instrumentation;Fil: Gendron, E.. Gepi - Galaxies, Etoiles, Physique, Instrumentation;Fil: Lacombe, F.. Gepi - Galaxies, Etoiles, Physique, Instrumentation;Fil: Lacour, S.. Gepi - Galaxies, Etoiles, Physique, Instrumentation;Fil: Lecacheux, J.. Gepi - Galaxies, Etoiles, Physique, Instrumentation;Fil: Lellouch, E.. Gepi - Galaxies, Etoiles, Physique, Instrumentation;Fil: Renner, S.. Gepi - Galaxies, Etoiles, Physique, Instrumentation;Fil: Pau, S.. Gepi - Galaxies, Etoiles, Physique, Instrumentation;Fil: Roques, F.. Gepi - Galaxies, Etoiles, Physique, Instrumentation;Fil: Widemann, T.. Gepi - Galaxies, Etoiles, Physique, Instrumentation;Fil: Colas, F.. Imcce - Institut de Mecanique Celeste Et de Calcul Des Ephemerides;Fil: Vachier, F.. Imcce - Institut de Mecanique Celeste Et de Calcul Des Ephemerides;Fil: Martins, R. Vieira. Imcce - Institut de Mecanique Celeste Et de Calcul Des Ephemerides; . Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Ageorges, N.. European Southern Observatory Santiago; ChileFil: Hainaut, O.. European Southern Observatory Santiago; ChileFil: Marco, O.. European Southern Observatory Santiago; ChileFil: Beisker, W.. International Occultation Timing Association;Fil: Hummel, E.. International Occultation Timing Association;Fil: Feinstein Baigorri, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Levato, Orlando Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico ; ArgentinaFil: Maury, A.. Gene Shoemaker Observatory; ChileFil: Frappa, E.. Planétarium de Saint-etienne;Fil: Gaillard, B.. Association Des Utilisateurs de Détecteurs Electroniques (aude);Fil: Lavayssière, M.. Association Des Utilisateurs de Détecteurs Electroniques (aude);Fil: Di Sora, M.. Campo Catino Austral Observatory; ChileFil: Mallia, F.. Campo Catino Austral Observatory; ChileFil: Masi, G.. Campo Catino Austral Observatory; Chile. Universita Tor Vergata; ItaliaFil: Behrend, R.. Universidad de Ginebra; SuizaFil: Carrier, F.. Universidad de Ginebra; SuizaFil: Mousis, O.. Observatoire de Besancon;Fil: Rousselot, P.. Observatoire de Besancon;Fil: Alvarez Candal, Alvaro Augusto. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Lazzaro, D.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Veiga, C.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; BrasilFil: Andrei, A.H.. Ministério de Ciencia, Tecnologia e Innovacao. Observatorio Nacional; Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Assafin, M.. Universidade Federal do Rio de Janeiro; BrasilFil: Da Silva Neto, D.N.. Universidade Federal do Rio de Janeiro; BrasilFil: Jacques, C.. Observatório CEAMIG-REA; BrasilFil: Pimentel, E.. Observatório CEAMIG-REA; BrasilFil: Weaver, D.. Universidade de Fortaleza;Fil: Lecampion, J.-F.. Observatoire Aquitain Des Sciences de L'univers;Fil: Doncel, F.. Universidad Nacional de Asunción; ParaguayFil: Momiyama, T.. Universidad Nacional de Asunción; ParaguayFil: Tancredi, G.. Facultad de Ciencias; Urugua