176 research outputs found
Modelado de la radiaciĂłn solar global horaria sobre superficie inclinada mediante redes neuronales artificiales
Ponencia presentada en: XXIX Jornadas CientĂficas de la AME y el VII Encuentro Hispano Luso de MeteorologĂa celebrado en Pamplona, del 24 al 26 de abril de 2006
Bottom-Water Conditions in a Marine Basin after the CretaceousâPaleogene Impact Event: Timing the Recovery of Oxygen Levels and Productivity
An ultra-high-resolution analysis of major and trace element contents from the CretaceousâPaleogene boundary interval in the Caravaca section, southeast Spain, reveals a quick recovery of depositional conditions after the impact event. Enrichment/depletion profiles of redox sensitive elements indicate significant geochemical anomalies just within the boundary ejecta layer, supporting an instantaneous recovery âsome 102 yearsâ of pre-impact conditions in terms of oxygenation. Geochemical redox proxies point to oxygen levels comparable to those at the end of the Cretaceous shortly after impact, which is further evidenced by the contemporary macrobenthic colonization of opportunistic tracemakers. Recovery of the oxygen conditions was therefore several orders shorter than traditional proposals (104â105 years), suggesting a probable rapid recovery of deep-sea ecosystems at bottom and in intermediate waters.This research was supported by Projects CGL2009-07603, CGL2008-03007, CGL2012-33281 and CGL2012-32659 (SecretarĂa de Estado de I+D+I, Spain), Projects RNM-3715 and RNM 05212, and Research Groups RNM-178 and 0179 (Junta de AndalucĂa)
The electrical double layer for a fully asymmetric electrolyte around a spherical colloid: an integral equation study
The hypernetted chain/mean spherical approximation (HNC/MSA) integral
equation is obtained and solved numerically for a totally asymmetric primitive
model electrolyte around a spherical macroparticle. The ensuing radial
distribution functions show a very good agreement when compared to our Monte
Carlo and molecular dynamics simulations for spherical geometry and with
respect to previous anisotropic reference HNC calculations in the planar limit.
We report an analysis of the potential vs charge relationship, radial
distribution functions, mean electrostatic potential and cumulative reduced
charge for representative cases of 1:1 and 2:2 salts with a size asymmetry
ratio of 2. Our results are collated with those of the Modified Gouy-Chapman
(MGC) and unequal radius Modified Gouy-Chapman (URMGC) theories and with those
of HNC/MSA in the restricted primitive model (RPM) to assess the importance of
size asymmetry effects. One of the most striking characteristics found is
that,\textit{contrary to the general belief}, away from the point of zero
charge the properties of an asymmetric electrical double layer (EDL) are not
those corresponding to a symmetric electrolyte with the size and charge of the
counterion, i.e. \textit{counterions do not always dominate}. This behavior
suggests the existence of a new phenomenology in the EDL that genuinely belongs
to a more realistic size-asymmetric model where steric correlations are taken
into account consistently. Such novel features can not be described by
traditional mean field theories like MGC, URMGC or even by enhanced formalisms,
like HNC/MSA, if they are based on the RPM.Comment: 29 pages, 13 figure
Administration of Linoleoylethanolamide Reduced Weight Gain, Dyslipidemia, and Inflammation Associated with High-Fat-Diet-Induced Obesity
Acylethanolamides (NAEs) are bioactive lipids derived from diet fatty acids that modulate important homeostatic functions, including appetite, fatty acid synthesis, mitochondrial respiration, inflammation, and nociception. Among the naturally circulating NAEs, the pharmacology of those derived from either arachidonic acid (Anandamide), oleic acid (OEA), and palmitic acid (PEA) have been extensively characterized in diet-induced obesity. For the present work, we extended those studies to linoleoylethanolamide (LEA), one of the most abundant NAEs found not only in plasma and body tissues but also in foods such as cereals. In our initial study, circulating concentrations of LEA were found to be elevated in overweight humans (body mass index (BMI, Kg/m) > 25) recruited from a representative population from the south of Spain, together with AEA and the endocannabinoid 2-Arachidonoyl glycerol (2-AG). In this population, LEA concentrations correlated with the circulating levels of cholesterol and triglycerides. In order to gain insight into the pharmacology of LEA, we administered it for 14 days (10 mg/kg i.p. daily) to obese male Sprague Dawley rats receiving a cafeteria diet or a standard chow diet for 12 consecutive weeks. LEA treatment resulted in weight loss and a reduction in circulating triglycerides, cholesterol, and inflammatory markers such as Il-6 and Tnf-alpha. In addition, LEA reduced plasma transaminases and enhanced acetyl-CoA-oxidase (Acox) and Uncoupling protein-2 (Ucp2) expression in the liver of the HFD-fed animals. Although the liver steatosis induced by the HFD was not reversed by LEA, the overall data suggest that LEA contributes to the homeostatic signals set in place in response to diet-induced obesity, potentially contributing with OEA to improve lipid metabolism after high fat intake. The anti-inflammatory response associated with its administration suggests its potential for use as a nutrient supplement in non-alcoholic steatohepatitis.Juan Decara holds a âMiguel Servetâ (CP21/00021) research contract from the Ministerio
de Ciencia e InnovaciĂłn, Instituto de Salud Carlos III (ISCIII), cofunded by European Social Fund,
âInvesting in your futureâ, Gobierno de España. The present work was funded by Instituto de Salud
Carlos III (ISCIII), Ministerio de Ciencia e InnovaciĂłn; European Regional Development Funds Euro-
pean Union (ERDF-EU) grants âProyectos de InvestigaciĂłn en Saludâ PI19/01577 and PI22/00427;
Proyectos de investigaciĂłn en salud (PI-0139-2018) ConsejerĂa de Salud y Familias, Junta de An-
dalucĂa, Proyecto de InvestigaciĂłn en Salud; grant for international postdoctoral stay âJose Castillejoâ
Program (Grant CAS15/00257), Ministerio de Educación Cultura y Deporte, Gobierno de España.
The funders had no role in the design of the study; in the collection, analysis, and interpretation of
data; in the writing of the report; and in the decision to submit the paper for publication
The Global Stratotype Section and Point (GSSP) for the base of the Lutetian Stage at the Gorrondatxe section, Spain
The GSSP for the base of the Lutetian Stage (early/
middle Eocene boundary) is defined at 167.85 metres in
the Gorrondatxe sea-cliff section (NW of Bilbao city,
Basque Country, northern Spain; 43Âș22'46.47" N, 3Âș 00'
51.61" W). This dark marly level coincides with the lowest
occurrence of the calcareous nannofossil Blackites
inflatus (CP12a/b boundary), is in the middle of polarity
Chron C21r, and has been interpreted as the maximumflooding
surface of a depositional sequence that may be
global in extent. The GSSP age is approximately 800 kyr
(39 precession cycles) younger than the beginning of
polarity Chron C21r, or ~47.8 Ma in the GTS04 time
scale. The proposal was approved by the International
Subcommission on Paleogene Stratigraphy in February
2010, approved by the International Commission of
Stratigraphy in January 2011, and ratified by the International
Union of Geological Sciences in April 2011.Published86-1082.2. Laboratorio di paleomagnetismoJCR Journalrestricte
Wet deposition in the remote western and central Mediterranean as a source of trace metals to surface seawater
Abstract. This study reports the only recent characterization of two contrasted wet deposition events collected during the PEACETIME (ProcEss studies at the AirâsEa Interface after dust deposition in the MEditerranean Sea) cruise in the open Mediterranean Sea (Med Sea) and their impact on trace metal (TM) marine stocks. Rain samples were analysed for Al, 12 TMs (Co, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Ti, V and Zn) and nutrient (N, P, dissolved organic carbon) concentrations. The first rain sample collected in the Ionian Sea (Rain ION) was a typical regional background wet deposition event, whereas the second rain sample collected in the Algerian Basin (Rain FAST) was a Saharan dust wet deposition event. Even in the remote Med Sea, all background TM inputs presented an anthropogenic signature, except for Fe, Mn and Ti. The concentrations of TMs in the two rain samples were significantly lower compared to concentrations in rains collected at coastal sites reported in the literature, due to the decrease in anthropogenic emissions during the preceding decades. The atmospheric TM inputs were mainly dissolved forms, even in dusty Rain FAST. The TM stocks in the mixed layer (ML, 0â20âm) at the FAST station before and after the event showed that the atmospheric inputs were a significant supply of particulate TMs and dissolved Fe and Co for surface seawater. Even if the wet deposition delivers TMs mainly in soluble form, the post-deposition aerosol dissolution could to be a key additional pathway in the supply of dissolved TMs. At the scale of the western and central Mediterranean, the atmospheric inputs were of the same order of magnitude as ML stocks for dissolved Fe, Co and Zn, highlighting the role of the atmosphere in their biogeochemical cycles in the stratified Med Sea. In case of intense dust-rich wet deposition events, the role of atmospheric inputs as an external source was extended to dissolved Co, Fe, Mn, Pb and Zn. Our results suggest that the wet deposition constitutes only a source of some of dissolved TMs for Med Sea surface waters. The contribution of dry deposition to the atmospheric TM inputs needs to be investigated.</jats:p
Ichnological analysis of the Messinian-Zanclean (Miocene-Pliocene) transition at Eraclea Minoa (Sicily): Tracemaker response to the Terminal Messinian Flood
A detailed ichnological analysis has been conducted, for the first time, of the Arenazzolo and Trubi formations of the Caltanissetta Basin in Sicily. Aim of this analysis is to evaluate paleoenvironmental changes affecting macrobenthic tracemaker communities during the re-flooding of the Mediterranean at the end of the Messinian Salinity Crisis. The uppermost Messinian Arenazzolo Formation is characterized by a scarcity of trace fossils, probably related to high energy depositional conditions, and perhaps no fully normal salinity level yet, resulting in an unfavourable habitat for macrobenthic tracemaker communities. The exclusive presence of small traces (Chondrites) sparsely distributed in several horizons is associated to intermittent phases of lower energy conditions facilitating colonization by opportunistic tracemakers. A significant change in trace fossil assemblages is observed at the transition to the Zanclean Trubi Formation. Here the ichnofossil assemblage consists of?Arenicolites, Chondrites, Halimedides, Palaeophycus, Planolites, Thalassinoides, Trichichnus and Zoophycos, assigned to the Zoophycos ichnofacies, revealing an abundant, diverse, well-developed, multi-tiered, tracemaker community. This change observed at the Messsinian/Zanclean boundary is related to the rapid establishment of normal, full-marine, conditions with well oxygenated bottom- and pore-waters, and food availability in a deep marine environment. Comparison with previous micropaleontological studies supports the magnitude of the paleoenvironmental change affecting both pelagic and benthic environments
Integrative stratigraphy and climatic events of a new lower paleogene reference section from the betic cordillera: RĂo gor, Granada province, se Spain
Research interest in the early Paleogene was greatly enhanced after the recognition of several short-lived warming events in that period (hyperthermals), considered ancient analogues of the ongoing warming of the Earth climate. In the Caravaca and Alamedilla sections, the previously most studied lower Paleogene sections of the Subbetic Zone (Betic Cordillera), only the most prominent of these hyperthermals had been located, the so-called Paleocene/Eocene Thermal Maximum. The RĂo Gor section, though less studied, is found to comprise a lower Paleogene succession that is more expanded and complete than Caravaca and Alamedilla; it contains record of the Early Late Paleocene and Paleocene/Eocene Thermal Events, and at least one additional Eocene hyperthermal, thus offering an excellent opportunity to study these climatic events in the Subbetic Zone. Study of the RĂo Gor section is still in progress, this paper summarizing the state-of-the art of ongoing research
Evolution of the gulf of Cadiz margin and southwest Portugal contourite depositional system : Tectonic, sedimentary and paleoceanographic implications from IODP expedition 339
Acknowledgments This research used samples and data collected through the Integrated Ocean Drilling Program (IODP). The research was partially supported through the CTM 2008-06399-C04/MAR, CTM 2012-39599-C03, CGL2011-26493, CTM2012-38248, SA263U14, IGCP-619, INQUA 1204 and FWF P25831-N29 Projects. Some data were collected with 94-1090-C03-03 (FADO) and MAR-98-0209 (TASYO) Projects. Research was conducted in the framework of the Continental Margins Research Group of the Royal Holloway University of London, People and the Program (Marie Curie Actions) of the European Union's Seventh Framework Program FP7/2007-2013/ under REA Grant Agreement No. 290201 MEDGATEâ. We are very grateful to REPSeOL, TGSâNOPEC, and the CSIC-Institut Jaume Almera (http://geodb.ictja.csic.es) for allowing us to use an unpublished seismic data from the Gulf of Cadiz. We thank J. Aguire (UGR, Spain) for comments and suggestions concerning the Pliocene and Quaternary outcrops, B. van den Berg (USAL) for organizing a thought-provoking field-trip to Cadiz, Spain in November, 2014, M. Ăngel Caja, L. GarcĂa Diego, and J. Tritlla (REPSOL) for provenance and diagenetic analysis of early Pliocene sandstones and debrites, and L.J. Lourens (Utrecht University) for providing us the eccentricity and 200-Kys glacio-eustatic sea-level curves included in the Figure 16. Both Prof. D.A.V. Stow (Heriot-Watt Univ., UK) and F.J. HernĂĄndez-Molina (RHUL, UK), as the main co-proponents of the IODP Proposal 644 and the co-chiefs of the IODP Exp. 339, thanks to IODP, Exp. IODP 339 Scientists; JR crew and technicians, as well as all people, institutions and companies involved in making IODP a success since 2003. Finally, we also thank the editor, Gert J. De Lange and the reviewers T. Mulder (Bourdeaux Univ.); D. Van Rooij (Ghent Univ) and J. Duarte (Monash Univ.) for their very positive and helpful feedback and discussions in publishing this research.Peer reviewedPublisher PD
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