115 research outputs found

    EVALUACIÓN DEL EFECTO FITOTÓXICO DE RIZOBACTERIAS DELETÉREAS SOBRE EL CRECIMIENTO RADICAL DE AXONOPUS AFFINIS (CHASE) Y LENS ESCULENTA (MOENCH)

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    Las malezas ocasionan una gran pérdida en las tierras agrícolas y comúnmente, las medidas de manejo y contención de estas especies se dan con la aplicación de herbicidas, sin embargo; en años recientes se ha presentado un interés en establecer mecanismos de biocontrol seguros, con el empleo de bacterias inhibidoras del crecimiento conocidas como rizobacterias deletéreas (Deleterious rhizobacteria: DRB)que se consideran generalmente como no parasíticas, y causan, de manera sutil, efectos deletéreos a través de la producción de metabolitos dañinos a las plantas. El presente trabajo tuvo como objetivo caracterizar la producción de ácido cianhídrico de pseudomonas rizobacterianas de malezas de un cultivo de alfalfa (Medicago sativa L.) y evaluar el efecto fitotóxico de éstas sobre el crecimiento radical de plántulas de Axonopus affinis (Chase) y Lens esculenta (Moench). De acuerdo con los resultados obtenidos con relación a la evidencia de que los aislados de pseudomonadas son rizobacterias cianogénicas y de su efecto fitotóxico medido sobre las especies vegetales bajo estudio; se sugieren a éstas como posibles agentes de biocontrol con pastos que sean considerados malezas; ya que en general se observó que inhiben su crecimiento radical; sin embargo, un enfoque particular lo tiene la rizobacteria Pseudomonas sp. A52, la cual presentó no solamente actividad como una DRB sino también como una rizobacteria promotora del crecimiento vegetal; lo que la hace más importante de analizar en cuanto a su potencial y espectro de acción; tanto para malezas monocotiledóneas como para dicotiledóneas, recomendable como un posible agente de biocontrol con actividad múltiple

    Antagonistic Interaction of Staphylococcus aureus Toward Candida glabrata During in vitro Biofilm Formation Is Caused by an Apoptotic Mechanism

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    Background: Infections caused by Candida species and Staphylococcus aureus are associated with biofilm formation. C. albicans–S. aureus interactions are synergistic due to the significant increase in mixed biofilms and improved resistance to vancomycin of S. aureus. C. glabrata and S. aureus both are nosocomial pathogens that cause opportunistic infections in similar host niches. However, there is scarce information concerning the interaction between these last microorganisms.Results: The relationship between C. glabrata and S. aureus was evaluated by estimating the viability of both microorganisms in co-culture of planktonic cells and in single and mixed biofilms. An antagonistic behavior of S. aureus and their cell-free bacterial supernatant (CFBS) toward C. glabrata, both in planktonic form and in biofilms, was demonstrated. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and confocal laser scanning microscopy (CLSM) images showed yeast cells surrounded by bacteria, alterations in intracytoplasmic membranes, and non-viable blastoconidia with intact cell walls. Concomitantly, S. aureus cells remained viable and unaltered. The antagonistic activity of S. aureus toward C. glabrata was not due to cell-to-cell contact but the presence of CFBS, which causes a significant decrement in yeast viability and the formation of numerous lipid droplets (LDs), reactive oxygen species (ROS) accumulation, as well as nuclear alterations, and DNA fragmentation indicating the induction of an apoptotic mechanism.Conclusion: Our results demonstrate that the S. aureus CFBS causes cell death in C. glabrata by an apoptotic mechanism

    EVALUACIÓN DEL EFECTO DE CADMIO SOBRE LA GERMINACIÓN Y ELONGACIÓN RADICAL DE SEMILLAS BACTERIZADAS DE AXONOPUS AFFINIS Y FESTUCA RUBRA

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    There has been reported different indexto biomonitoring the phytotoxic effects ofmetals in plants; one of them is based on the germination and plant lets growth, eventhough the root promotion is a major marker which measures the beneficial effect ofplant growth promoting rhizobacteria. Thepresent study analyzed the bacterizationeffect on germination and root elongationof Axonopus affinis (Chase) and Festucarubra L., as protection and promotingplant growth mechanisms at the expositionto a heavy metal. The seeds bacterizationwith the rhizobacteria Pseudomonas sp.Sp7D of both species, showed its promoting potential in the germination and theplantlets grown as its protecting potentialin cadmium presence for both species;even that A. affinis (Chase) showed too ahormetic response with cadmium and thetolerance to it.Se han reportado diferentes índices parabiomonitorear los efectos de fitotoxicidad demetales en plantas y uno de esos indicadoresestá basado en la germinación y desarrollode las plántulas; así mismo, la promoción delas raíces es uno de los principales marcadores con los que se mide el efecto benéfico delas rizobacterias promotoras del crecimientovegetal. El presente estudio analizó el efectode la bacterización sobre la germinación yelongación radical de Axonopus affinis (Chase) y Festuca rubra L., como mecanismosde protección y promoción del crecimientoante la exposición a un metal pesado.La bacterización de las semillas con la rizobacteria Pseudomonas sp. Sp7D en ambasespecies reflejó tanto su potencial promotordel crecimiento en la germinación y el crecimiento de las plántulas, donde éstos fueronmayores para Festuca rubra; como su potencial protector ante la presencia de cadmio(Cd) para ambas especies; no obstante queAxonopus affinis (Chase) mostró tambiénuna respuesta hormética ante la presenciadel metal y la tolerancia a éste

    Evolution of the gulf of Cadiz margin and southwest Portugal contourite depositional system : Tectonic, sedimentary and paleoceanographic implications from IODP expedition 339

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    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 MEDGATE’. We are very grateful to REPSeOL, TGS–NOPEC, 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. Ángel Caja, L. García 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. Hernández-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

    Bottom-Water Conditions in a Marine Basin after the Cretaceous–Paleogene Impact Event: Timing the Recovery of Oxygen Levels and Productivity

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    An ultra-high-resolution analysis of major and trace element contents from the Cretaceous–Paleogene 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 –some 102 years– 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 (104–105 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 (Secretaría de Estado de I+D+I, Spain), Projects RNM-3715 and RNM 05212, and Research Groups RNM-178 and 0179 (Junta de Andalucía)

    The Global Stratotype Section and Point (GSSP) for the base of the Lutetian Stage at the Gorrondatxe section, Spain

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    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; 43º22'46.47" N, 3º 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

    National identity predicts public health support during a global pandemic

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    Changing collective behaviour and supporting non-pharmaceutical interventions is an important component in mitigating virus transmission during a pandemic. In a large international collaboration (Study 1, N = 49,968 across 67 countries), we investigated self-reported factors associated with public health behaviours (e.g., spatial distancing and stricter hygiene) and endorsed public policy interventions (e.g., closing bars and restaurants) during the early stage of the COVID-19 pandemic (April-May 2020). Respondents who reported identifying more strongly with their nation consistently reported greater engagement in public health behaviours and support for public health policies. Results were similar for representative and non-representative national samples. Study 2 (N = 42 countries) conceptually replicated the central finding using aggregate indices of national identity (obtained using the World Values Survey) and a measure of actual behaviour change during the pandemic (obtained from Google mobility reports). Higher levels of national identification prior to the pandemic predicted lower mobility during the early stage of the pandemic (r = −0.40). We discuss the potential implications of links between national identity, leadership, and public health for managing COVID-19 and future pandemics

    Social and moral psychology of COVID-19 across 69 countries

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    The COVID-19 pandemic has affected all domains of human life, including the economic and social fabric of societies. One of the central strategies for managing public health throughout the pandemic has been through persuasive messaging and collective behaviour change. To help scholars better understand the social and moral psychology behind public health behaviour, we present a dataset comprising of 51,404 individuals from 69 countries. This dataset was collected for the International Collaboration on Social & Moral Psychology of COVID-19 project (ICSMP COVID-19). This social science survey invited participants around the world to complete a series of moral and psychological measures and public health attitudes about COVID-19 during an early phase of the COVID-19 pandemic (between April and June 2020). The survey included seven broad categories of questions: COVID-19 beliefs and compliance behaviours; identity and social attitudes; ideology; health and well-being; moral beliefs and motivation; personality traits; and demographic variables. We report both raw and cleaned data, along with all survey materials, data visualisations, and psychometric evaluations of key variables
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