Unraveling the sulfate sources of (giant) gypsum crystals using gypsum isotope fractionation factors.

We combine newly determined isotope fractionation factors of gypsum precipitated in the laboratory with the isotopic compositions of natural anhydrite and gypsum to unravel the sulfate sources of the giant selenite crystals in the Naica mine (Chihuahua, Mexico). Gypsum was precipitated in the laboratory from CaSO4-NaCl-H2O solutions across a broad temperature range to establish the isotopic fractionation behavior of the sulfate molecule between the solid and dissolved phase. Oxygen isotopes show a significant fractionation dependence on temperature, with the solid phase more depleted in light isotopes with decreasing temperature. Sulfur isotopes display only a weak but similar dependence on temperature. At high salinity (4.5 M NaCl) no temperature dependence was found for the isotope composition. Based on this fractionation behavior, we attempt to elucidate the origin of the sulfate source(s) responsible for the formation of the (giant) gypsum crystals in the Naica mine. Detailed analysis of the isotopic composition of anhydrite, gypsum, and water samples strongly suggests that different types of anhydrite (of hypogenic and sedimentary origin) were dissolved to form these unique gypsum formations. The homogeneous isotopic composition of most gypsum crystals analyzed reveals an effective hydrodynamic mixing and a slow kinetics of precipitation fed by solutions of calcium sulfate from different anhydrite sources

Survival of Atlantic bluefin tuna (Thunnus thynnus) larvae hatched at different salinity and pH conditions

In this study, we assessed the effect of environmental salinity and pH as independent factors on larval survival of Atlantic bluefin tuna (ABFT –Thunnus thynnus) together with their whole-body Na+/K+-ATPase and v-type H+-ATPase activities. Fertilized eggs of ABFT were obtained from a spontaneous spawning of broodstock in the farming facilities at El Gorguel (Cartagena, SE Spain) and were transferred to facilities of the Spanish Institute of Oceanography (IEO) in Mazarrón (SE Spain). In a first experiment, eggs (200 fertilized eggs L-1 per treatment, in 3 replicates) were exposed to different salinities treatments and constant pH 8.0 (control) until hatch was completed (50 h post- fertilization, hpf, at 23 ºC): 27, 30, 33, 36, 37, 38 (control), 39, 40, 43, 46 and 49 ppt. In a second experiment eggs (200 fertilized eggs L-1, in 3 replicates) were exposed to seawater salinity (SW: 38 ppt) and four reduced pH treatments until hatch was completed (50 hpf at 23 ºC): 8.0 (control), 7.7, 7.5 and 7.3. An inverse „„U-shaped‟‟ relationship was observed between environmental salinity and number of hatched larvae. An opposite pattern was observed for both Na+/K+-ATPase and H+-ATPase activities in hatched larvae, increasing both activities in groups exposed to extreme salinities. Thus, larval survival was higher at intermediate salinities and lower at the extreme salinities tested. These results suggest higher survival rates with lower active pumps activities. No significant differences in larval survival were observed with pH treatment, but lower H+-ATPase activity was detected at control environmental pH (pH 8.0). Survival results are discussed in terms of osmoregulatory cost adapting to a salinity and pH predicted for the near future scenarios.Versión del edito

¿Estamos de acuerdo con la calidad técnica de nuestras radiografías de tórax? Un radiólogo, un técnico especialista en radiodiagnóstico y un médico de familia intentan corroborarlo

ObjetivoValorar el grado de concordancia en la interpretación de la calidad técnica de las radiografías de tórax de un centro de salud entre el técnico especialista en radiodiagnóstico (TER), el médico de familia y el radiólogo.DiseñoEstudio transversal.EmplazamientoAtención primaria. Centro de Salud de Cartuja en Granada.ParticipantesPacientes del Centro de Salud de Cartuja con estudio radiológico simple de tórax durante 2002. Mediante muestreo aleatorio simple se seleccionaron 150 estudios. Se rechazaron 2 por tratarse de exploraciones repetidas del mismo paciente y 7 porque no presentaban una calidad mínima. La muestra final fue de 141 exploraciones.Mediciones principalesLos observadores cumplimentaron independientemente, para cada exploración, un protocolo de 11 ítems sobre calidad técnica de la imagen. Para cada ítem se calculó el índice kappa entre parejas de observadores, así como el índice kappa global.ResultadosEl 96% de las exploraciones fuerealizado con placas radiográficas de gran tamaño (35×43). Sólo en 2 preguntas hubo una concordancia aceptable o buena entre los 3 observadores (kappa=0,559-0,858). En 5 preguntas, la concordancia fue homogéneamente baja (kappa=0,034-0,375). En algunas preguntas se apreció una fuerte discrepancia entre la valoración del TER y la realizada por los otros 2 observadores.ConclusionesLa concordancia general puede considerarse baja, aunque algo mayor entre el radiólogo y el médico de familia que entre cada uno de éstos y el TER. Esto plantea la necesidad de mejorar la formación de los profesionales en cuanto a la valoración de la calidad técnica de las imágenes. Además, se detecta un gasto innecesario de placas radiográficas de gran tamaño.ObjectiveTo appraise the degree of concordance in the interpretation of the technical quality of chest x-rays at a health centre between an expert in x-ray diagnosis, a family doctor, and a radiologist.DesignTransversal study.SettingPrimary care. Cartuja Health Centre, Granada, Spain.ParticipantsPatients at the Cartuja Health Centre who had a simple chest x-ray in 2002. 150 studies were chosen by simple randomised sampling.Two were rejected because they dealt with a repeat examination of the same patient and seven because they did not reach minimum quality. The final sample was 141 x-rays.Main measurementsThe observers filled in independently, for each examination, an 11- item protocol on the technical quality of the images. The kappa index between pairs of observers was calculated for each item, as was the overall kappa index.Results96% of the examinations were conducted with large x-ray plates (35×43). There was only acceptable or good concordance between the 3 observers in 2 questions (kappa, 0.559-0.858). In 5 questions concordance was homogeneously low (kappa, 0.034-0.375). In some questions there was a strong discrepancy between the appraisal of the expert and that of the 2 other observers.ConclusionsGeneral concordance can be considered low, although it is somewhat greater between the radiologist and the family doctor than between either of these and the expert. This poses the need to improve professional training in evaluation of the technical quality of images. In addition, there was unnecessary expense in large-size x-ray plates

Towards a HAB forecast service in the Galician region

We will present the recent developments of our forecasting capabilities to warn of impending harmful algal blooms (HABs) in Galicia, where aquaculture has a strong socio-economic impact. A HAB warning service for monitoring agencies and the aquaculture industry has been developed as a demonstration of a Copernicus marine downstream service coupled to the MyOcean service. In this contribution, we describe the Galician ASIMUTH forecast system and demonstrate its skill in predicting HAB transport and its usefulness to provide assessment for the management of the areas affected by toxic outbreaks. We also describe the Galician pilot HAB bulletins, aimed at distributing forecasts of HAB events that might induce closures of harvesting areas or, when the areas are already closed, at giving information on forthcoming oceanographic conditions that could favour or hamper the opening of an area. Our results show that the model forecasts and the bulletins can provide early warning of the risk of Dinophysis spp. events and the risk of closures linked to the presence of toxins above regulatory levels in harvesting areas.Instituto Español de Oceanografí

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SURVIVAL OF ATLANTIC BLUEFIN TUNA (THUNNUS THYNNUS) LARVAE HATCHED AT DIFFERENT PH AND SALINITY CONDITIONS

In this study, we assessed the effect of pH and salinity as independent factors on larval survival (LS) of Atlantic bluefin tuna (ABFT –Thunnus thynnus) together with their Na+/K+-ATPase and V-type H+-ATPase activities. Fertilized eggs of ABFT were obtained on 25 June 2016 from a spontaneous spawning of broodstock in the farming facilities at El Gorguel (Cartagena, SE Spain) of Caladeros del Mediterráneo Company. The fertilized eggs were transferred to facilities of the Spanish Institute of Oceanography (IEO) in Mazarrón (SE Spain). In a first experiment, eggs (n = 150 per treatment, in 3 replicates) were exposed to sea water salinity (SW: 38 ppt) and four pH treatments until hatch was completed (44 hours at 23 ºC): 8.0 (control), 7.7 (near future), 7.5 (far future) and 7.3 (lower). In a second experiment eggs (n = 150 per treatment, in 3 replicates) were exposed to eleven salinities treatments and constant pH 8.0 (control) until hatch was completed (44 hours at 23 ºC): 27 , 30 , 33 , 36 , 37 , 38 (control), 39 , 40 , 43 , 46 and 49 ppt. No significant differences in LS were observed with pH treatment, but lower H+-ATPase activity was detected at control environmental pH (pH 8.0). A ‘‘U-shaped’’ relationship was observed between hatching salinity and both Na+/K+-ATPase and H+-ATPase activities in whole larvae hatched, increasing both activities in groups exposed to extreme salinities. However, LS showed an inverse “U shape” curve respect to environmental salinity with higher values at intermediate salinities and lower LS at extreme salinities. These results suggest higher survival rates with lower active pumps activities. Survival results are discussed in terms of osmoregulatory cost adapting to a pH and salinity predicted for the near future scenarios. This work was funding by the European Union’s Horizon 2020research and innovation programme under Grant Agreement No. 678193

Multi-production of high added market value metabolites from diluted methane emissions via methanotrophic extremophiles

Producción CientíficaThis study constitutes the first-proof-of-concept of a methane biorefinery based on the multi-production of high profit margin substances (ectoine, hydroxyectoine, polyhydroxyalkanoates (PHAs) and exopolysaccharides (EPS)) using methane as the sole carbon and energy source. Two bubble column bioreactors were operated under different magnesium concentrations (0.2, 0.02 and 0.002 g L−1) to validate and optimize this innovative strategy for valorization of CH4 emissions. High Mg2+ concentrations promoted the accumulation of ectoine (79.7–94.2 mg g biomass−1), together with high hydroxyectoine yields (up to 13 mg g biomass−1) and EPS concentrations (up to 2.6 g L culture broth−1). Unfortunately, PHA synthesis was almost negligible (14.3 mg L−1) and only found at the lowest Mg2+ concentration tested. Halomonas, Marinobacter, Methylophaga and Methylomicrobium, previously described as ectoine producers, were dominant in both bioreactors, Methylomicrobium being the only described methanotroph. This study encourages further research on CH4 biorefineries capable of creating value out of GHG mitigation.Ministerio de Economía, Industria y Competitividad (Project CTM2015-70442-RNOVEDAR)Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. E-47-2014-0140696UIC71

Novel haloalkaliphilic methanotrophic bacteria: An attempt for enhancing methane bio-refinery

Producción CientíficaMethane bioconversion into products with a high market value, such as ectoine or hydroxyectoine, can be optimized via isolation of more efficient novel methanotrophic bacteria. The research here presented focused on the enrichment of methanotrophic consortia able to co-produce different ectoines during CH4 metabolism. Four different enrichments (Cow3, Slu3, Cow6 and Slu6) were carried out in basal media supplemented with 3 and 6% NaCl, and using methane as the sole carbon and energy source. The highest ectoine accumulation (∼20 mg ectoine g biomass−1) was recorded in the two consortia enriched at 6% NaCl (Cow6 and Slu6). Moreover, hydroxyectoine was detected for the first time using methane as a feedstock in Cow6 and Slu6 (∼5 mg g biomass−1). The majority of the haloalkaliphilic bacteria identified by 16S rRNA community profiling in both consortia have not been previously described as methanotrophs. From these enrichments, two novel strains (representing novel species) capable of using methane as the sole carbon and energy source were isolated: Alishewanella sp. strain RM1 and Halomonas sp. strain PGE1. Halomonas sp. strain PGE1 showed higher ectoine yields (70–92 mg ectoine g biomass−1) than those previously described for other methanotrophs under continuous cultivation mode (∼37–70 mg ectoine g biomass−1). The results here obtained highlight the potential of isolating novel methanotrophs in order to boost the competitiveness of industrial CH4-based ectoine production.Ministerio de Economía, Industria y Competitividad (Project CTM2015-70442-R project and Red NOVEDAR)Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. UIC71)European Union through the FEDER Funding Program (PhD Grant contract Nº E-47-2014-0140696