An extrasolar planetary system with three Neptune-mass planets

Over the past two years, the search for low-mass extrasolar planets has led to the detection of seven so-called 'hot Neptunes' or 'super-Earths' around Sun-like stars. These planets have masses 5-20 times larger than the Earth and are mainly found on close-in orbits with periods of 2-15 days. Here we report a system of three Neptune-mass planets with periods of 8.67, 31.6 and 197 days, orbiting the nearby star HD 69830. This star was already known to show an infrared excess possibly caused by an asteroid belt within 1 AU (the Sun-Earth distance). Simulations show that the system is in a dynamically stable configuration. Theoretical calculations favour a mainly rocky composition for both inner planets, while the outer planet probably has a significant gaseous envelope surrounding its rocky/icy core; the outer planet orbits within the habitable zone of this star.Comment: 17 pages, 3 figures, preprint of the paper published in Nature on May 18, 200

Libri minores de nouo correcti per Antonivm Nebrissensem ...

Contiene: Libri Catonis. De contemptu mundi. Aesopi Fabulae. Floretus. Liber quinque clavium sapientiaeCopia digital : Junta de Comunidades de Castilla-La Mancha, 2010Pie de imp. consta en colofónSign.: A-H\p8\sPort. con orla tip. ornamentalLetra gót

VILLANUEVA DE LOS INFANTES (Ciudad Real). 1:8.600

Manuscrito firmado y rubricado por el autor. A plumilla en tintas negra, marrón y roja.Indica orientación con flecha, N. al NO.Indica relieve representado por sombreadoIndica caminos.Relación de los puntos principales indicados mediante clave alfabética

Oracion funebre y panegyrica, que en las reales exequias, que el dia veinte y siete de noviembre de mil setecientos y cinquenta hizo el Colegio Mayor de San Ildefonso Universidad de Alcalá de Henares ... á la ... memoria del ... rey D. Juan el Quinto de Portugal ...

Licencia del ordinario fechada en Alcalá de Henares, 1751Sign.: A4, 2[parágrafo]4-4[parágrafo]4, A-B4, C

CASTELLAR DE LA FRONTERA (Cádiz). 1:6.000

Manuscrito firmado y rubricado por el autor. A plumilla en tinta negra y coloreado a la acuarela en azul, carmín, verde y gris.Indica orientación con rosa de 8 puntas y lis.Indica relieve representado por curvas de nivel y sombreado.Indica sobre el plano los nombres de los accidentes geográficos.Sello en tinta del Depósito General Topográfico de Ingenieros.Sello en tinta Cuerpo de Ingenieros de la Administación General Nacional.Señala vegetación representada en algunas zonas

JIMENA DE LA FRONTERA (Cádiz). 1:5.000

Manuscrito a plumilla en tintas negra y carmín y coloreado a la acuarela en gris, carmín, azul y siena.Indica orientación con lis en rosa de los vientos y cuadrante.Relieve representado por sombreado.Indica "Tenerias", canal, caminos y la posición de las tropas

Reconciliation of the carbon budget in the ocean’s twilight zone

Photosynthesis in the surface ocean produces approximately 100 gigatonnes of organic carbon per year, of which 5 to 15 per cent is exported to the deep ocean1, 2. The rate at which the sinking carbon is converted into carbon dioxide by heterotrophic organisms at depth is important in controlling oceanic carbon storage3. It remains uncertain, however, to what extent surface ocean carbon supply meets the demand of water-column biota; the discrepancy between known carbon sources and sinks is as much as two orders of magnitude4, 5, 6, 7, 8. Here we present field measurements, respiration rate estimates and a steady-state model that allow us to balance carbon sources and sinks to within observational uncertainties at the Porcupine Abyssal Plain site in the eastern North Atlantic Ocean. We find that prokaryotes are responsible for 70 to 92 per cent of the estimated remineralization in the twilight zone (depths of 50 to 1,000 metres) despite the fact that much of the organic carbon is exported in the form of large, fast-sinking particles accessible to larger zooplankton. We suggest that this occurs because zooplankton fragment and ingest half of the fast-sinking particles, of which more than 30 per cent may be released as suspended and slowly sinking matter, stimulating the deep-ocean microbial loop. The synergy between microbes and zooplankton in the twilight zone is important to our understanding of the processes controlling the oceanic carbon sink

Resource Quantity Affects Benthic Microbial Community Structure and Growth Efficiency in a Temperate Intertidal Mudflat

Estuaries cover <1% of marine habitats, but the carbon dioxide (CO2) effluxes from these net heterotrophic systems contribute significantly to the global carbon cycle. Anthropogenic eutrophication of estuarine waterways increases the supply of labile substrates to the underlying sediments. How such changes affect the form and functioning of the resident microbial communities remains unclear. We employed a carbon-13 pulse-chase experiment to investigate how a temperate estuarine benthic microbial community at 6.5°C responded to additions of marine diatom-derived organic carbon equivalent to 4.16, 41.60 and 416.00 mmol C m−2. The quantities of carbon mineralized and incorporated into bacterial biomass both increased significantly, albeit differentially, with resource supply. This resulted in bacterial growth efficiency increasing from 0.40±0.02 to 0.55±0.04 as substrates became more available. The proportions of diatom-derived carbon incorporated into individual microbial membrane fatty acids also varied with resource supply. Future increases in labile organic substrate supply have the potential to increase both the proportion of organic carbon being retained within the benthic compartment of estuaries and also the absolute quantity of CO2 outgassing from these environments