803 research outputs found

    Unravelling the active microbial community in a thermophilic anaerobic digester-microbial electrolysis cell coupled system under different conditions

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    Thermophilic anaerobic digestion (AD) of pig slurry coupled to a microbial electrolysis cell (MEC) with a recirculation loop was studied at lab-scale as a strategy to increase AD stability when submitted to organic and nitrogen overloads. The system performance was studied, with the recirculation loop both connected and disconnected, in terms of AD methane production, chemical oxygen demand removal (COD) and volatile fatty acid (VFA) concentrations. Furthermore, the microbial population was quantitatively and qualitatively assessed through DNA and RNA-based qPCR and high throughput sequencing (MiSeq), respectively to identify the RNA-based active microbial populations from the total DNA-based microbial community composition both in the AD and MEC reactors under different operational conditions. Suppression of the recirculation loop reduced the AD COD removal efficiency (from 40% to 22%) and the methane production (from 0.32 to 0.03 m3m-3d-1). Restoring the recirculation loop led to a methane production of 0.55 m3m-3d-1concomitant with maximum MEC COD and ammonium removal efficiencies of 29% and 34%, respectively. Regarding microbial analysis, the composition of the AD and MEC anode populations differed from really active microorganisms. Desulfuromonadaceae was revealed as the most active family in the MEC (18%–19% of the RNA relative abundance), while hydrogenotrophic methanogens (Methanobacteriaceae) dominated the AD biomass.Postprint (author's final draft

    Overcoming organic and nitrogen overload in thermophilic anaerobic digestion of pig slurry by coupling a microbial electrolysis cell

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    The combination of the anaerobic digestion (AD) process with a microbial electrolysis cell (MEC) coupled to an ammonia stripping unit as a post-treatment was assessed both in series operation, to improve the quality of the effluent, and in loop configuration recirculating the effluent, to increase the AD robustness. The MEC allowed maintaining the chemical oxygen demand removal of the whole system of 46 ± 5% despite the AD destabilization after doubling the organic and nitrogen loads, while recovering 40 ± 3% of ammonia. The AD-MEC system, in loop configuration, helped to recover the AD (55% increase in methane productivity) and attained a more stable and robust operation. The microbial population assessment revealed an enhancement of AD methanogenic archaea numbers and a shift in eubacterial population. The AD-MEC combined system is a promising strategy for stabilizing AD against organic and nitrogen overloads, while improving the quality of the effluent and recovering nutrients for their reutilization.Postprint (author's final draft

    El Sermo Vulgaris frente a la Romana ungua de Lorenzo Valla (e. 1407-1457) en el ApĂłlogo 1 contra Poggio Bracciolini (1380-1459)

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    The polemic between two notable humanists, Poggio Bracciolini (1380-1459) and LorenzoValla (c.1407- 1457), is intensified during the perio between 1451 and 454. The influence of the Disceptatio III by Poggie Bracciolini in 1450, where he expresses his concept of the different “uses” of the sermo vulgaris, and the Orationis Invectivae. Made against the Elegantiae or Romana linguo by Lorenzo Valla, become commendable N the Apologues II and I by the Elegantiae’ s author. In this latter scenic dialog, which is the subject of our study, Valla would bitingly try to blame Poggio Bracciolini for writing by using an incorrect Latin, placing him at the same level of the sermo vulgaris or vocabulum culinarium spoken by his cook or his stableman, The falseness of these accusations would be defended by Poggio in his Quinta Invectiva

    MammoApplet: an interactive Java applet tool for manual annotation in medical imaging

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    Web-based applications in computational medicine have become increasingly important during the last years. The rapid growth of the World Wide Web supposes a new paradigm in the telemedicine and eHealth areas in order to assist and enhance the prevention, diagnosis and treatment of patients. Furthermore, training of radiologists and management of medical databases are also becoming increasingly important issues in the field. In this paper, we present MammoApplet , an interactive Java applet interface designed as a web-based tool. It aims to facilitate the diagnosis of new mammographic cases by providing a set of image processing tools that allow a better visualization of the images, and a set of drawing tools, used to annotate the suspicious regions. Each annotation allows including the attributes considered by the experts when issuing the final diagnosis. The overall set of overlays is stored in a database as XML files associated with the original images. The final goal is to obtain a database of already diagnosed cases for training and enhancing the performance of novice radiologistsPeer ReviewedPostprint (author's final draft

    Nitrogen removal in a two-chambered microbial fuel cell: Establishment of a nitrifying-denitrifying microbial community on an intermittent aerated cathode

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    A microbial fuel cell (MFC) was used to study nitrogen dynamics and its feasibility for high strength wastewater treatment. Intermittent aeration was applied on the cathode chamber accomplishing the establishment of a simultaneous nitrifying-denitrifying microbial community. A total of 30.4% of the N-NH4 + migrated through the ion exchange membrane being primarily nitrified at the cathode chamber. When intermittent aeration was applied in the cathode, denitrification also occurred achieving 17.8% of nitrate removal without acetate addition, and 41.2% with acetate addition. The microbial community analysis revealed that the nitrification process at the cathode chamber could be explained due to a high predominance of Nitrosomonas sp. as ammonia-oxidising bacteria and other Comamonadaceae phylotypes as potential denitrifiers. Parallel batch denitrification assays, carried out outside the MFC using the cathode effluent, confirmed the existence of heterotrophic denitrification processes with other well known denitrifying dominant phylotypes enrichment (Burkholderiadaceae, Comamonadaceae, Alcaligenaceae).Postprint (author's final draft
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