59 research outputs found
L'Espagne et le Portugal illustrés
No full textTiene un sello de la Viuda de Alonso e Hijos, Librería general, LugoEn pag. 370 consta la fecha de 1902Port. a dos tintasTexto a dos colLos mapas en col. y bl. y
Praxis ecclesiastica et saecularis ...
No full textInterpolación tomada de cabeza de pagSign.: [calderón]\p4\s, A-Z\p4\s, 2A-2Z\p4\s, 3A-3Y\p4\s, 3Z\p6\s, A-M\p4\s, N\p6\sTexto a dos colLos tres tomos, y "Decisiones" con pag. propia
Transient situations in nitrate assimilation by marine diatoms. V. Interspecific variability in biomass and uptake during nitrogen starvation and resupply
No full text
Blooms of surf-zone diatoms along the coast of the Olympic Peninsula, Washington. IV. Nitrate reductase activity in natural populations and laboratory cultures of Chaetoceros armatum and Asterionella socialis
No full textPraxis ecclesiastica et saecularis ...
No full textCopia digital : Diputación Provincial de Zaragoza, 2015Interpolación tomada de cabeza de pag.Sign.: [calderón]\p4\s, A-Z\p4\s, 2A-2Z\p4\s, 3A-3Y\p4\s, 3Z\p6\s, A-M\p4\s, N\p6\sTexto a dos colLos tres tomos, y "Decisiones" con pag. propia
Cartas eruditas por la preferencia de la philosophia aristotelica para los estudios de religion [Texto impreso]
No full textSe trata de una coleccion de 12 cartas enviadas por Vicente Calatayud a Andres Piquer, que se fueron publicando separadamente y que aquí aparecen reunidas bajo una portada común. Todas están impresas por los herederos de Jeronimo Conejos, la primera carta está fechada en 1758 y la última en 1760Pie de imp. tomado de colLos datos de los editores estas tomados del v. de la portSign.: A16, A-D4, E2, *-4*4, A-E4, F2, a-e4, a-d4, e2, [calderón]-5[calderón]4, H-5H4, 6H2, I-5I4, K-3K4, 4K5, L-6L4, 7L5, M-7M4Iniciales grab. xi
Nitrogen nutrition of harmful algal blooms in upwelling systems
No full textBlooms of toxic, or otherwise harmful phytoplankton species are known to occur in eastern boundary upwelling systems, coincident with the relaxation of upwelling in latesummer/autumn. Field studies were carried out in 3 consecutive summers (March/April 06-08)in the Benguela and in the autumn (Sept 06) and summer (June 07) in the Iberian upwelling system (Ría de Vigo), with the aim of identifying common nitrogen nutrition strategies of HAB species that may allow them to succeed in upwelling systems. Two summer field studies were also carried out in the Fal Estuary (UK) to identify possible differences between a UK estuary and these upwelling systems.In the Benguela, three toxic phytoplankton species were dominant under different nutrient conditions. Pseudo-nitzschia spp. were abundant during a period of strong upwelling and high NO3-, peaking during short periods of wind relaxation. During these periods, a switch from highnitrate uptake [(NO3 -)] to regenerated nitrogen uptake [(NH4 +) and (urea)] occurred, with ƒratios dropping from 0.79 to 0.12. Alexandrium catenella bloomed during a period of upwelling, displaying high (NO3-) and ƒ-ratios up to 0.87. Dinophysis acuminata dominated when NO3- concentrations were <0.5 ?mol l-1 and ƒ-ratios <0.1 in 2007, although in 2008 it formed a subsurface maximum, often associated with high NO3- concentrations. Nutrient uptake kinetics showed that Pseudo-nitzschia spp. displayed the highest maximum specific uptake rates (max).D. acuminata displayed the highest affinity for NH4+, as shown by its values (slope of the nutrient uptake vs. concentration curve). Thus, A. catenella was adapted to utilising high NO3- concentrations during upwelling pulses, whereas both Pseudo-nitzschia and D. acuminata wereable to acclimate to both high and low NO3- concentrations during the upwelling/relaxation cycles. In the Ría de Vigo, warm water from the stratified shelf entered the ría and downwelled in September, resulting in a well-mixed water column. The phytoplankton assemblage, dominated by Ceratium spp., Dinophysis acuminata and Gymnodinium catenatum, appeared to be advected in to the ría. Nitrate concentrations were consistently low, whereas NH4+ concentrations increased towards the head of the ría and with depth. The phytoplankton community was dependent on regenerated nitrogen, with ƒ-ratios <0.2. In contrast, positive circulation in June resulted in strong vertical gradients in temperature, salinity and nutrients and a community dominated by diatoms. Nitrate and NH4+ were depleted in surface waters although uptake rates were higher than in September, as were the ƒ-ratios (0.1-0.3).In both systems, upwelling winds favoured diatoms, although they were able to utilise regenerated nitrogen when NO3- was depleted, whereas upwelling relaxation created favourable conditions for HAB development. Dinophysis spp. occurred in both systems and were able to grow on recycled nitrogen in the absence of NO3-. The Benguela showed high variability in the selection of particular HAB species, perhaps due to greater variability in upwelling-downwellingcycles. In the Ría de Vigo, the occurrence of downwelling and associated nutrient conditions leading to blooms of Dinophysis spp. and Gymnodinium catenatum seems more predictable.In the Fal Estuary, Alexandrium spp. was favoured by low irradiance and the combination of strong stratification and high nutrient concentrations, and its growth was sustainedpredominantly by NH4+. A. minutum strains isolated from both upwelling systems and from a UK Lagoon all displayed higher max for NH4+ relative to NO3- but higher growth rates on the latter. This was consistent with field results from all 3 regions, suggesting that the upwelling systems did not display a different order of nitrogen preference, although they did display a higher affinity for NO3-
Isotopic and enzymatic analyses of planktonic nitrogen utilisation in the vicinity of Cape Sines (Portugal) during weak upwelling activity
No full textEffect of marine autotrophic dissolved organic matter (DOM) on Alexandrium catenella in semi-continuous cultures
No full text10 pages, 6 figuresAlexandrium catenella was grown in semi-continuous cultures in L1 growth-medium enriched with concentrated dissolved organic matter (DOM) from a diatom bloom. In medium with full nitrate (880 µM), the average growth rate was 0.32 ± 0.01 day–1 (L1, control without added DOM). Adding natural marine dissolved organic nitrogen (DON) at levels of 20–30 µM above background (10 µM) led to a higher growth rate (L1+DOM, 0.40 ± 0.00 day–1). In medium with lower nitrate level (175 µM) and higher DON (L1/5+DOM treatment), both dissolved inorganic nitrogen and DON were used, leading to the highest growth rates (0.43 ± 0.03 day–1). In medium without nitrate [(L1-N)+DOM treatment], the low ammonium concentrations observed throughout the experiment (<1 µM) as well as the uptake kinetics of A. catenella could not have supported the observed growth rates, leading us to conclude that DON was directly used by this organism, rather than using N remineralized by bacteria (from DON). The decrease of bacteria in DOM enriched bioassays could point to a nutrient limitation and competition with A. catenella for organic matter. Viruses likely contributed as an additional factor to keep the bacterial population from becoming dominantThis study was supported by the EC-funded Research Project SEED (Life cycle transformations among HAB species, and the environmental and physiological factors that regulate them; GOCE-CT-2005-003875), by the contract between ACA and CSIC, and by PROCAVIR (CTM2004-04404-CO2-01) and MICROVIS (CTM2007-62140) projects. S.L. was supported by a FCT (Fundação para a Ciência e para a Tecnologia, Portugal) grant within the III Quadro Comunitário de Apoio by the FSE; E.G. was supported by the Ramon y Cajal contract of the Spanish Ministry of Education and Science. Y.C. was supported by CNRS (Centre National de la Recherche Scientifique) and Ifremer (Institut Français de Recherche pour l'Exploitation de la Mer) ALTOX programPeer reviewe
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