Dissolved inorganic carbon fixation of Thaumarchaeota vs. Bacteria in the meso- and upper bathypelagic waters of the world’s oceans differentiated with the use of metabolic inhibitors

Recent studies suggest that the dark ocean prokaryotes fix inorganic carbon at rates substantially higher than assumed. We have studied the contribution of Archaea vs. Bacteria to total prokaryotic fixation of dissolved inorganic carbon (DIC) in the meso- and upper bathypelagic waters of the world’s oceans during the Malaspina circumnavigation expedition carried out between December 2010 and July 2011. We used the metabolic inhibitor Erythromycin, an antibiotic specifically inhibiting growth of Bacteria but not affecting Archaea. Bacteria dominated throughout the water column in the three major ocean basins (54% of the total DAPI counts), decreasing in their relative contribution to total prokaryotic abundance from the surface to the meso- and bathypelagic waters. By contrast, the relative contribution of Thaumarchaeota was generally higher in the meso- and bathypelagic layers than in the surface waters (up to 29% of the total DAPI counts in the Pacific Ocean). Averaged over the entire water column, Thaumarchaeota contributed 8%, 33% and 18% to the total prokaryotic DIC fixation in the Indian, Pacific and Atlantic Ocean, respectively. The contribution of Thaumarchaeota to total prokaryotic DIC fixation increased with depth, particularly in the Atlantic below 1000 m depth and in the lower mesopelagic zone of the Pacific Ocean. Preliminary results from an station in the Atlantic Ocean, combining microautoradiography and fluorescence in situ hybridization (MICRO-CARD-FISH), confirmed that both Thaumarchaeota and some bacterial groups such as SAR 324 take up DIC. Thaumarchaeota and SAR 324 accounted for 7 % and 12% of DIC-positive DAPI-stained cells, respectively, as revealed by MICRO-CARD-FISH. Our results suggest that some phylogenetic groups may be significant contributors to the dark ocean chemoautotrophy

Response of phytoplankton to enhanced atmospheric and riverine nutrient inputs in a coastal upwelling embayment

Original research paperOver the past decades, as a consequence of human activity, there was an increase in nutrient inputs to the ocean and they are expected to enhance even more in the future. Coastal areas, accounting for a significant proportion of marine primary productivity, are the most vulnerable zones to anthropogenic impacts. The response of phytoplankton communities to an increase in organic and inorganic nutrients levels from natural allochthonous sources was assessed in microcosm experiments conducted in a coastal system affected by intermittent upwelling events (Ría de Vigo, NW Iberia). Three nutrient addition experiments were performed in spring, summer and autumn, when surface water was supplemented with 5 and 10% of atmospheric and riverine matter. Pico-, nano- and microphytoplankton abundances, chlorophyll a concentration (Chl a) and primary production rates (PP) were measured and compared with those in the control seawater sample (without additions) after 48 h of incubation. Simultaneous experiments with controlled additions of inorganic and organic nutrients were also performed in order to describe the limiting nutrient for phytoplankton growth at each experiment. The composition of the matter inputs and the structure of the phytoplankton communities determined the type of response observed. Phytoplankton responses varied among seasons, being positively correlated with dissolved inorganic nitrogen (DIN) concentrations. As expected, the phytoplankton responses to external nutrient inputs were stronger under low nutrient levels (summer) than when phytoplankton was already growing in nutrient replete conditions (spring). Null and negative responses to the natural inputs were observed in autumn, which suggests that the oceanic phytoplankton advected to this coastal system during downwelling events could be occasionally inhibited by these nutrient inputs. In a future global change scenario, characterized by enhanced nutrient inputs from riverine and atmospheric origin, the response of phytoplankton communities will strongly depend on the concentration and chemical composition of these inputs and on the structure of phytoplankton communities able to respond to themSpanish Ministry of Science and Innovation (project REIMAGE CTM2011-30155); Spanish Ministry of Economy and Competitiviness (project iSmall, reference CTM2014-56119-R); Portuguese Foundation for Science and Technology (reference SFRH/BPD/188485/2015); ESF (reference JAE DOC 040) and MINECO (project FERMIO reference CTM2014-57334-JIN)Versión del edito

Radiocarbon dates for the late Pleistocene and Early Holocene occupations of Cova Rosa (Ribadesella, Asturias, Spain)

Four excavations have been performed at the archaeological site of Cova Rosa (Asturias, Cantabrian Spain): three of them in the second half of last century and the other in this decade. Although little of the archaeological material found in those excavations has been published, here we attempt the stratigraphic correlation of sections revealed by the different excavations and we present 22 new radiocarbon dates for bones and marine shells, built in a Bayesian statistical model. This has enabled the documentation of occupations that mainly took place during the Last Glacial period, in the Solutrean (middle and upper phases) and Magdalenian (archaic, lower, and upper phases), and also in the early Holocene (Mesolithic). These occupations are compared with the record at other sites in Cantabrian Spain in general and in Asturias, in particular.Introduction Cova Rosa Cave - Geographical and Geological Setting - History of Research - Stratigraphy Radiocarbon dates at Cova Rosa - Method - Validity Analysis - Results and Critical Assessment - Solutrean - Magdalenian - Mesolithic Discussion: 14C chronology of Cova Rosa Conclusion

Bacterioplankton responses to riverine and atmospheric inputs in a coastal upwelling system (Ría de Vigo, NW Spain)

Original research paperAnthropogenic pressures are changing the magnitude and nature of matter inputs into the ocean. The Ría de Vigo (NW Spain) is a highly productive and dynamic coastal system that is likely affected by such alterations. Previous nutrient-addition microcosm experiments conducted during contrasting hydrographic conditions suggested that heterotrophic bacteria are limited by organic carbon (C) and occasionally co-limited by inorganic nutrients in this coastal area. In order to assess short-term responses in biomass, production, and respiration of heterotrophic bacteria from the Ría de Vigo to increasing amounts of natural inputs of matter, we conducted 6 microcosm experiments, wherein surface seawater collected in spring, summer, and autumn was mixed with increasing amounts of dissolved natural matter concentrates from riverine and atmospheric origin. Simultaneous experiments with controlled inorganic and/or organic additions indicated that bacteria were co-limited by inorganic nutrients and C in spring and summer and primarily limited by C in autumn. Production responded more than biomass to increasing inputs of matter, whereas respiration did not change. The bacterial production response to increasing dissolved organic C load associated with riverine and atmospheric inputs was strongly related to the relative phosphorus (P) content of the dissolved matter concentrates. Our data suggest that bacterial production might decrease with the increase of P-deficient allochthonous matter inputs, which would have important biogeochemical consequences for C cycling in coastal areas.Spanish Ministry of Science and Innovation, MINECO, CSIC, Xunta of Galicia and European Union (Marie Curie Grants)Versión del edito

Corrigendum to "Biogeography of planktonic bacterial communities across the whole Mediterranean Sea" published in Ocean Sci., 9, 585–595, 2013

No abstract available

Efecto de la suplementación pre parto y oferta de alimento durante la recría sobre la producción de carne de novillitos

La eficiencia de producción de carne y la duración de los ciclos productivos dependen principalmente del manejo nutricional de vacas y sus crías. Los terneros necesitan menos alimento para producir un kg de peso vivo (PV) con respecto a un novillito. Su potencial debe ser aprovechado para enviar a faena animales jóvenes con un adecuado nivel de engrasamiento. El objetivo del presente trabajo fue evaluar el efecto de la suplementación pre-parto y su relación con el nivel de oferta de una ración concentrada base maíz sobre el crecimiento, desempeño productivo y calidad de carne de novillitos livianos. Se utilizaron 48 terneros destetados precozmente provenientes de un rodeo con o sin suplementación y se distribuyeron en 4 tratamientos según un diseño factorial 2x2 para evaluar el efecto de la suplementación de las vacas y de una recría con o sin restricción nutricional durante la recría. Se evaluó el aumento diario de PV (ADPV), consumo, conversión, espesor de grasa dorsal (EGD) y área de ojo de bife (AOB). Los novillitos se faenaron con 380-390 kg PV a los 11-14 meses de edad y se evaluó rendimiento y calidad de la carne sobre muestras de longissimus dorsi. Los terneros recriados sin restricción consumieron el 2,5% PV y presentaron una ganancia de 1,2 kg/cab/día (cabeza), mientras que los animales con restricción en la oferta de alimento (1,8% PV) ganaron 0,9 kg/cab/d (día). La suplementación de las vacas durante el último tercio de gestación no afectó la producción ni la calidad de la carne. Sin embargo, se observó una interacción de los factores sobre el EGD, AOB y rendimiento de res. La experiencia tuvo una duración de 17 meses y se obtuvo información inédita de producción, rendimiento de res y calidad de carne de novillitos alimentados con una dieta sin fibra larga

Integrase strand-transfer inhibitors for treatment of early HIV infection : A case series

This study evaluated whether the interval from the first clinic visit until the start of antiretroviral treatment (ART) was correlated with common parameters of immunological recovery among patients with early HIV infection (EHI).We reviewed the medical records of patients with EHI who started ART using integrase strand-transfer inhibitors (ISTIs) within the first 6 months after diagnosis. Simple linear regression analyses were performed to determine whether the interval from the first visit to the start of ART was correlated with 1-year changes in CD4+ cell count, CD8+ cell count, CD4+ percentage, and CD4+/CD8+ ratio.Fifty-three patients with probable or definite EHI started ART using ISTIs between April 2014 and August 2016. Forty-nine patients completed 1 year of follow-up, including 48 men. The routes of HIV transmission were 1 case of needle sharing, 5 cases of heterosexual activity, and 43 cases of men who had sex with men. None of the immunological recovery parameters were correlated with time to the start of ART (CD4+ cell count: R = .12, P = .42; CD8+ cell count: R = .107, P = .5; CD4+ percentage: R = .14, P = .34; CD4+/CD8+ ratio: R = .23, P = .14). Furthermore, subgroup sensitivity analyses failed to detect significant correlations based on definite or probable diagnoses, treatment using elvitegravir or dolutegravir, or the time from HIV diagnosis to ART initiation.This series of EHI cases indicate that using ART with ISTI-based regimens is efficacious and well-tolerated. However, earlier initiation of treatment was not significantly correlated with common parameters of immunological recovery

Bacterial community composition and optical signature of DOM shape empirical leucine-to-carbon conversion factors in north-eastern Atlantic waters (0-4000 m)

Oral communicationMicrobial heterotrophic activity is a major process regulating the flux of dissolved organic matter (DOM) in the ocean. DOM quantity and quality strongly influence its microbial utilization and fate in the ocean. In order to broaden the vertical resolution of leucine-to-carbon conversion factors (CFs), needed for converting substrate incorporation into biomass production by heterotrophic bacteria, nine dilution experiments were performed in the north Atlantic. We found a very consistent depth-stratification in empirical CFs values from epipelagic to bathypelagic waters (3.95 ± 0.05 to 0.90 ± 0.51 kg C mol Leu-1). Our results demonstrated that the customarily used CF of 1.55 kg C mol Leu-1 in oceanic waters leads to an underestimation of prokaryotic heterotrophic production in epi- and mesopelagic waters, while it causes a severe overestimation in bathypelagic waters. Pearson correlations showed that CFs were related not only to hydrographic variables but also to specific phylogenetic groups and DOM quality and quantity indicators. Furthermore, a multiple linear regression model predicting CFs from relatively simple hydrographic and optical spectroscopic measurements is provided. Taken together, our results suggest that differences in CFs throughout the water column might be mostly associated to the quality of DOM affecting the response of particular phylogenetic groups.ASL

Efecto de las prácticas durante el manejo pre-faena sobre el rendimiento de la carne de bovinos

Meat quality begins to be defined since the farm period. Intensive production systems that aim to maximize production must preserve animal welfare and harmlessness meat for consumer safety. Comfort, feeding and genetics contribute to obtaining a well finishing animal. While long-term stress affects the characteristics and preservation of meat products. Currently, the production systems and the management that are provided to the animals during the breeding, transport and pre-slaughter management are deficient to reach the productive potential and the quality required by the consumers. For these reasons, it is important to address the limiting factors in production and pour them into the production chain. The objective of this review is to report the effects of good livestock practices and pre-slaughter management on beef performance and meat quality.La calidad de la carne comienza a definirse desde la etapa de producción primaria. Los sistemas intensivos que se orientan a maximizar la producción deben garantizar el bienestar animal y la calidad de la carne. El confort de los animales, la alimentación y la genética contribuyen a la obtención de una res bien conformada. Por el contrario, los eventos de estrés prolongado repercuten negativamente sobre las características y la conservación de los productos cárnicos. Actualmente, los sistemas productivos y el manejo que se brinda a los animales durante la crianza, transporte y manejo pre faena son deficientes para alcanzar el potencial productivo y la calidad requerida por los consumidores. Por lo expuesto, es importante abordar los factores limitantes en la producción y vertirlos en la cadena productiva. El objetivo de la presente revisión es abordar los efectos de las buenas prácticas ganaderas y el manejo previo a la faena sobre el rendimiento de res y la calidad de la carne