The mOxy-CaL Process: Integration of Membrane Separation, Partial Oxy-combustion and Calcium Looping for CO2 Capture

CO2 capture and storage (CCS) is considered as a key strategy in the short to medium term to mitigate global warming. The Calcium-Looping process, based on the reversible carbonation/calcination of CaO particles, is a promising technology for post-combustion CO2 capture because of the low cost and non-toxicity of natural CaO precursors and the minor energy penalty on the power plant in comparison with amines capture based technologies (4-9 % compared to 8-12 %). Another interesting process to reduce CO2 emissions in power plants is oxy-combustion, which is based on replacing the air used for combustion by a highly concentrated (~95 % v/v) O2 stream. This work proposes a novel process (mOxy-CaL) for post-combustion CO2 capture based on the integration of membrane separation, partial oxy-combustion and the Calcium-Looping process. An oxygenenriched air stream, which is obtained from air separation by using highly permeable polymeric membranes, is used to carry out partial oxy-combustion. The flue gas exiting partial oxy-combustion shows a CO2 concentration of ~30 % v/v (higher than 15 % v/v typical in coal power plants). After that, the flue gas is passed to the CaL process where the CO2 reacts with CaO solids according to the carbonation reaction. Thermogravimetric analysis show that the multicycle CaO conversion is enhanced as the CO2 concentration in the flue gas stream is increased. Process simulations show that the mOxy-CaL process has a high CO2 capture efficiency (~95%) with lower energy consumption per kg of CO2 avoided than previously proposed post-combustion CO2 capture technologies. Moreover, the overall system size is significantly lower that state-of-the-art CaL systems, which allows for an important reduction in the capital cost of the technology

Topographical control of the source‐sink and wind stress‐driven planetary geostrophic circulation in a polar basin

The effects of topography on the barotropic circulation in a polar basin are examined analytically and numerically. New approximate linear analytical solutions are presented for steady‐state wind and boundary forced barotropic planetary geostrophic circulation in a circular polar basin with a step shelf. The solutions are obtained by retaining the full spherical geometry in the derivation of the forced potential vorticity equation; thereafter the colatitude is fixed in the coefficients of this governing equation. The accuracy of the analytical solutions is evaluated by comparing them with the equivalent numerical solutions obtained using the NEMO modeling system. Subsequently, the impact of a nonuniform width shelf on source‐sink‐driven circulation is investigated numerically. The equipartition of fluid entering the source strait into cyclonic and anticyclonic shelf currents, exiting the basin at the sink strait, in a basin with a uniform width shelf is shown to be modified when the shelf width varies. In general, the wider shelf supports a current with larger transport, irrespective of the azimuthal extent of the wider shelf. The study concludes with a numerical investigation of wind‐driven circulation in a basin with a step shelf, three straits, and a transpolar ridge, a prototype Arctic Ocean simulation. Topographic steering by the ridge supports a transpolar drift current, the magnitude of which depends on the ridge height. Without the ridge, the transpolar drift current is absent and the circulation is confined to gyres on the shelf and in the deep basin

The probiotic Shewanella putrefaciens PDP11 target virulence factors by modulating quorum sensing inhibition

Bacteria communicate with each other by producing signal molecules and regulating the production of virulence factors that have importance in pathogenicity. Quorum sensing (QS) is a bacterial communication mechanism based on the perception of population density and secretion of determining signal molecules called autoinducers (AI) such as the case of Acylhomoserine lactones (AHLs). AHLs-mediated QS processes seem to be common in the marine environment and among marine pathogenic bacteria, which pathogenesis could be mitigated by probiotics, among others. Probiotics are defined as live microbial cells that confer health benefits to the host and some of their mechanisms include the production of antagonistic compounds that are inhibitory toward pathogens. In this sense, Shewanella putrefaciens Pdp11, a strain described as a probiotic for use in aquaculture, has been analysed to mediate QS processes by quorum-quenching assays using synthetic AHLs. The enzymatic activity is estimated at around 80% and 30% for C8- and C10-HSL, respectively, while the rest of AHLs tested were not degraded by the Pdp11 strain. It would be an interesting feature of the probiotic Pdp11 strain since these AHLs are related to facilitating microbial adhesion by promoting biofilm formation among other virulence factors related to pathogens. On the other hand, a distinctive feature of AHL inactivated by lactonase is that it can be reactivated by acid treatment. In this way, little C8-AHL was recovered when it is extracted to pH2, which indicates the enzyme activity is not derived from the hydrolysis of the lactone ring derived from the action of lactonases, suggesting the enzyme activity in Pdp11 could be an AHL-acylase. The potential QQ activity of Pdp11 was unknown so, these preliminary studies led to a further as another promising probiotic QQ tool for aquaculture

Role of Anions in 5-Hydroxymethylfurfural Solvation in Ionic Liquids from Molecular Dynamics Simulations

The proper selection of solvents for biomass upgrading is a crucial task as it should carefully balance the enhancement of reactivity with a facile product recovery. A challenging case is the conversion of glucose and fructose to 5-hydroxymethylfurfural (HMF). Ionic liquids (ILs) are often employed to boost the activity and selectivity of this process, although the isolation of HMF from the medium remains a major drawback. To investigate such solvent effects in a realistic (dynamic) environment, classical molecular dynamics (MD) simulations of HMF are performed in imidazolium-based ILs with different anions. Several parameters are identified that directly control HMF–anion interactions, which may hamper product separation, as well as HMF–HMF contacts, which can promote undesired side-reactions. These computational results would guide future high-throughput screenings of new and improved IL mediaThis work was funded by the Spanish Ministry of Economy and Competitiveness (under projects MAT2017-89239-C2-1-P and PID2020-119116RA-I00) and by the Xunta de Galicia (ED431D 2017/06, ED431E 2018/08, GRC ED431C 2016/001, and GRC ED431C 2020/10). All these projects were partially supported by FEDER. H.M.C. thanks the USC for his “Convocatoria de Recualificación do Sistema Universitario Español-Margarita Salas” postdoctoral grant under the “Plan de Recuperación Transformación” program funded by the Spanish Ministry of Universities with European Union's NextGenerationEU funds. T.M.M. acknowledges her contract funded by the pilot program of the USC for the recruitment of distinguished research personnel—call 2021 under the agreement between the USC and the Santander Bank for 2021–2024. M.A.O. acknowledges the Xunta Distinguished Researcher program (ED431H 2020/21), the Xunta de Galicia (Centro singular de investigación de Galicia accreditation 2019–2022, ED431G 2019/03), and the European Union (European Regional Development Fund – ERDF) for funding. He also acknowledges CESGA (“Centro de Supercomputación de Galicia”) for providing computational resourcesS

Mean sea-level variability along the northeast American Atlantic coast and the roles of the wind and the overturning circulation

The variability in mean sea level (MSL) during 1950–2009 along the northeast American Atlantic coast north of Cape Hatteras has been studied, using data from tide gauges and satellite altimetry and information from the Liverpool/Hadley Centre (LHC) ocean model, thereby providing new insights into the spatial and temporal scales of the variability. Although a relationship between sea level and the overturning circulation can be identified (an increase of approximately 1.5 cm in MSL for a decrease of 1 Sv in overturning transport), it is the effect of the nearshore wind forcing on the shelf that is found to dominate the interannual sea-level variability. In particular, winds are found to be capable of producing low-frequency changes in MSL (“accelerations”) in a narrow coastal band, comparable to those observed by the tide gauges. Evidence is presented supporting the idea of a “'common mode” of spatially coherent low-frequency MSL variability, both to the north and south of Cape Hatteras and throughout the northwest Atlantic, which is associated with large spatial-scale density changes from year to year

Inhibition of alpha oscillations through serotonin-2A receptor activation underlies the visual effects of ayahuasca in humans

Ayahuasca is an Amazonian psychotropic plant tea typically obtained from two plants, Banisteriopsis caapi and Psychotria viridis. It contains the psychedelic 5-HT2A and sigma-1 agonist N,N-dimethyltryptamine (DMT) plus ß-carboline alkaloids with monoamine-oxidase (MAO)-inhibiting properties. Although the psychoactive effects of ayahuasca have commonly been attributed solely to agonism at the 5-HT2A receptor, the molecular target of classical psychedelics, this has not been tested experimentally. Here we wished to study the contribution of the 5-HT2A receptor to the neurophysiological and psychological effects of ayahuasca in humans. We measured drug-induced changes in spontaneous brain oscillations and subjective effects in a double-blind randomized placebo-controlled study involving the oral administration of ayahuasca (0.75 mg DMT/kg body weight) and the 5-HT2A antagonist ketanserin (40 mg). Twelve healthy, experienced psychedelic users (5 females) participated in four experimental sessions in which they received the following drug combinations: placebo+placebo, placebo+ayahuasca, ketanserin+placebo and ketanserin+ayahuasca. Ayahuasca induced EEG power decreases in the delta, theta and alpha frequency bands. Current density in alpha-band oscillations in parietal and occipital cortex was inversely correlated with the intensity of visual imagery induced by ayahuasca. Pretreatment with ketanserin inhibited neurophysiological modifications, reduced the correlation between alpha and visual effects, and attenuated the intensity of the subjective experience. These findings suggest that despite the chemical complexity of ayahuasca, 5-HT2A activation plays a key role in the neurophysiological and visual effects of ayahuasca in humans.Postprint (published version

Adsorption of salmonella in clay minerals and clay-based materials

A series of clay minerals and clay-based materials have been tested to eliminate one of the most dangerous bacteria we can find in the water: Salmonella. It has been proven that the use of clays and their PCH materials can be a suitable method for removing Salmonella from water. The results of this initial study show that all the materials analyzed have great salmonella adsorption capacities ranging from the lowest value observed in the mont-PCH sample (0.29 × 1010 CFU g−1 ) to the highest value observed in the natural palygorskite sample (1.52 × 1010 CFU g−1 ). Macroporosity, accessible external surface area, and the presence of silanol groups in the external surface of the particles appears to be the controlling factors for Salmonella adsorption capacity while it seems that the structural characteristics of the clay minerals and their respective PCH does not affect the adsorption capacityThe authors wish to thank the project BIA2017-82391-R for the financial suppor

Potential postbiotic activities of extracellular products of probiotic bacteria from gilthead seabream gastrointestinal tract

Probiotics have been established as a potential tool for improving gut health and environmental quality in aquaculture. However, recent evidence suggests that bacterial viability is not necessary to attain the beneficial-promoting effects. In this way, postbiotics have emerged providing a potential opportunity in the field of functional foods. They are soluble factors resulting from the metabolic activity of a probiotic or any released molecule, including short-chain fatty acids, enzymes, extracellular products, etc. that can have interesting properties inducing biological responses on health similar to probiotics while avoiding the administration of live microorganisms. Interestingly, its production can be affected by different factors such as the components of the culture media among others. Information on this type of postbiotic activities is very scarce, especially in the case of aquaculture, so the evaluation of the nutraceutical use of postbiotics to improve health management in fish and other cultivated aquatic organisms is an emerging area of research in aquaculture. In a previous work, we characterized four potential probiotics that were isolated from the gastrointestinal tract of Sparus aurata specimens fed with a diet containing a blend of microalgae. This diet involves a selection pressure on the intestinal microbiota of the fish that will be used to achieve enrichment in bacteria with a set of extracellular enzymatic activities capable of metabolizing and mobilizing the components of the diet enriched with microalgae. Here, we investigate the postbiotic potential of the extracellular products (ECPs) obtained from the four candidate probiotics grown on different microalgae-supplemented medium, and evaluate its enzymatic and antibacterial activity, and its cytotoxicity against the SAF-1 cell line. Our objective is to select different ECPs with a variety of activities that help the digestive process of seabream, with the aim to be included in aquafeeds.This work was funded by Junta de Andalucía (grant no. P20_00085) and co-financed by FEDER funds

Expresión de genes del sistema inmune innato del lenguado (Solea senegalensis) alimentados con Ulva ohnoi durante la infección con P. damselae subsp. piscicida

Las algas son fuente de proteínas y numerosas sustancias biológicamente activas. En el caso del género Ulva, son muy escasos los estudios sobre los efectos en el sistema inmune. En el presente trabajo se ha evaluado la respuesta a la infección por P. damselae subsp. piscicida de genes del sistema inmune innato en lenguados (Solea senegalensis) alimentados con una dieta suplementada con Ulva ohnoi. Los ejemplares de lenguado con un peso inicial de 10,7g se alimentaron durante 3 meses con una dieta control y otra conteniendo 5% de polvo seco de U. ohnoi. Transcurrido este periodo, los peces (54,17 g) se sometieron a infección frente a P. damselae subsp. piscicida y se determinó la expresión relativa de los genes que codifican para componentes del sistema del complemento, y citoquinas inflamatorias en hígado y riñón de los lenguados infectados. Los resultados obtenidos muestran, tras la infección, un incremento en la expresión de los genes que codifican para los componentes C1q4, C3, C4/1 y C9 así como TNF en el hígado de los peces que recibieron el alga. Por el contrario, se observaron niveles inferiores de expresión de los genes que codifican para las citoquinas IL1beta, IL6 e IL8b en el hígado de los ejemplares que recibieron el alga. A nivel del riñón, los lenguados alimentados con la dieta conteniendo Ulva sólo presentaron diferencias respecto al grupo control en la expresión de los genes que codifican para IL8b y C9. La activación del sistema del complemento da como resultado la formación del complejo de ataque de membrana, que tiene un papel esencial en la eliminación de microorganismos patógenos. Por otro lado, una respuesta inflamatoria controlada puede contribuir a limitar el daño derivado de la infección por P. damselae subsp. piscicida, en peces alimentados con la dieta conteniendo Ulva.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Ministerio de Ciencia de Innovación y FEDER (Ref. RTA2014 00023 C02

In vitro assessment of antagonistic activities of isolates from gilthead seabream (Sparus aurata) gastrointestinal tract fed microalgae supplemented diet

The use of probiotics has emerged as a sustainable alternative to antibiotics in the control of infectious diseases, favouring fish health management, growth performance and feed utilisation, among others. microalgae represent an interesting source of nutrients and functional ingredients for aquafeeds. However, their digestibility is often limited by the presence of anti-nutritional factors or absence of appropriate enzymatic activities in the fish gastrointestinal tract (GIT). The aims of the present work were to isolate potential probiotics from the GIT of Sparus aurata fed with a diet containing 25 % microalgae and characterize their antagonism against fish pathogens. Altogether, 117 strains were isolated from juvenile seabream (146.8 ± 16.4 g) and screened for hydrolytic enzyme activities. Results showed that 48 %, 41 %, 77 % and 30 % of isolates were able to hydrolyse protein, lipids, collagen and starch, respectively. Moreover, 46 %, 8 % and 57 % of isolates exhibited the ability to degrade phytate, tannins and cellulose, respectively. Based on these results, a total of 32 isolates were selected for inhibitory activity against several fish pathogens assessment. Inhibition against Aeromonas hydrophila and Vibrio anguillarum was detected in 38 % of the isolates, whilst 44 % and 47 % inhibited P damselae subsp. damselae and P. damselae subsp. piscicida, respectively. Inhibition abilities were detected in the isolates when tested against Tenacibaculum species. Thus, 56 % inhibited Tenacibaculum maritimum; 63 % T. soleae and 22 % T. gallaecium. Overall, results showed that three strains display ability to hydrolyse 4 of the assayed substrates and produce inhibition against 8 fish pathogens, and two strains are capable to hydrolyse 5 substrates and inhibit 8 fish pathogens. Selected strains show characteristics to be considered for further characterization as potential probiotics in gilthead seabream aquaculture and microalgae-supplemented aquafeeds.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech