Nutrient dynamics and related future challenges in Kongsfjorden

Resumen de la conferencia inauguralAbstract The Arctic has waned four times faster than the rest of the world due to Global Warming. In the model Arctic ecosystem of Kongsfjorden (Svalbard archipelago, 79 ºN) warming has occurred more intensely in winter. A warmer winter has led ice-free fjord surface all year round. Under this conditions hydrodynamics are changed and, along with it, the biological and other physicochemical dynamics. Seaweeds start its production when light is available in the water column. Typically, this used to occur in May, after the ice break-up. Late spring-early summer used to be the season when both phytoplankton and the seaweeds forest would uptake the available nutrient and produce biomass. This production season ends during late summer due to nutrient limitation. The atmospheric workgroup has identified the spring as the time of the year with pronounce nutrient-N deposition in the fjord, and the glaciologist has measured that virtually all nutrient deposited over glaciers end up in the fjord water system. Regarding biological primary production, timing of both light and N availability is key. An ice-free N-rich spring may anticipate the season of macroalgal forests productivity and removal of nutrients. We support evidence that macroalgal possess newly developed photosynthetic tissue at the end of the winter, ready to photosynthesise as soon as light is available in February-March. If N removal is intensified by productivity season anticipation, N-limitation could take place before the development of phytoplankton bloom, normally occurring in late Spring. Since most of the animal production relies on phytoplankton productivity, season anticipation of N-limitation has the potential to drastically change the ecosystem.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Representación narrativa de madres maduras: estudio de casos en la cinematografía española y japonesa

A pesar de que la población madura femenina constituye la mayoría de los envejecientes del primer mundo, los medios de comunicación muestran un rechazo social hacia la mujer mayor. Así, en el medio cinematográfico, la mujer que supera los cincuenta años suele aparecer caracterizada por su escasa relevancia y su vinculación a argumentos que giran en torno a las enfermedades, la soledad, la muerte, la angustia por el deterioro físico o la remembranza de otros tiempos. El presente artículo se centra en la figura de la mujer de edad avanzada como madre y en su relación con hijos o hijas adultos e independientes. Para ello, se estudian seis películas procedentes de dos filmografías tan dispares como la española y la japonesa en un intento de buscar similitudes y disimilitudes culturales, sociales y fílmicas entre estos personajes femeninos cuyos únicos nexos de intersección son la edad y la maternidad. Por parte del cine español se han elegido los filmes Solas (Benito Zambrano, 1999), Volver (Pedro Almodóvar, 2006) y La soledad (Jaime Rosales, 2007) para ser cotejados con tres películas japonesas de la última década: I just didn't do it (Masayuki Suo, 2006), Tokyo Tower: Mom and Me, and Sometimes Dad (Joji Matsuoka, 2007) y Still walking (Hirokazu Koreeda, 2008)

Rubisco carboxylation kinetics and inorganic carbon utilization in polar versus cold-temperate seaweeds

Despite the high productivity and ecological importance of seaweeds in polar coastal regions, little is known about their carbon utilization mechanisms, especially the kinetics of the CO2-fixing enzyme Rubisco. We analyzed Rubisco carboxylation kinetics at 4 °C and 25 °C in 12 diverse polar seaweed species (including cold-temperate populations of the same species) and the relationship with their ability to use bicarbonate, by using 13C isotope discrimination and pH drift experiments. We observed a large variation in Rubisco carboxylation kinetics among the selected species, although no correlation was found between either the Michaelis–Menten constant for CO2 (Kc) or Rubisco content per total soluble protein ([Rubisco]/[TSP]) and the ability to use bicarbonate for non-green seaweeds. This study reports intraspecific Rubisco cold adaptation by means of either higher Rubisco carboxylation turnover rate (kcatc) and carboxylase efficiency (kcatc/Kc) at 4 °C or higher [Rubisco]/[TSP] in some of the analyzed species. Our data point to a widespread ability for photosynthetic bicarbonate usage among polar seaweeds, despite the higher affinity of Rubisco for CO2 and higher dissolved CO2 concentration in cold seawater. Moreover, the reported catalytic variation within form ID Rubisco might avert the canonical trade-off previously observed between Kc and kcatc for plant Rubiscos

Increased temperature and CO2 alleviate photoinhibition in Desmarestia anceps: from transcriptomics to carbon utilization

Ocean acidification and warming are affecting polar regions with particular intensity. Rocky shores of the Antarctic Peninsula are dominated by canopy-forming Desmarestiales. This study investigates the physiological and transcriptomic responses of the endemic macroalga Desmarestia anceps to a combination of different levels of temperature (2 and 7 °C), dissolved CO2 (380 and 1000 ppm), and irradiance (65 and 145 μmol photons m−2 s−1). Growth and photosynthesis increased at high CO2 conditions, and strongly decreased at 2 °C plus high irradiance, in comparison to the other treatments. Photoinhibition at 2 °C plus high irradiance was evidenced by the photochemical performance and intensive release of dissolved organic carbon. The highest number of differentially regulated transcripts was observed in thalli exposed to 2 °C plus high irradiance. Algal 13C isotopic discrimination values suggested an absence of down-regulation of carbon-concentrating mechanisms at high CO2. CO2 enrichment induced few transcriptomic changes. There was high and constitutive gene expression of many photochemical and inorganic carbon utilization components, which might be related to the strong adaptation of D. anceps to the Antarctic environment. These results suggest that increased temperature and CO2 will allow D. anceps to maintain its productivity while tolerating higher irradiances than at present conditions

Biochemical composition of temperate and Arctic populations of Saccharina latissima after exposure to increased pCO2 and temperature reveals ecotypic variation

Previous research suggested that the polar and temperate populations of the kelp Saccharina latissima represent different ecotypes. The ecotypic differentiation might also be reflected in their biochemical composition (BC) under changing temperatures and pCO2. Accordingly, it was tested if the BC of Arctic (Spitsbergen) and temperate S. latissima (Helgoland) is different and if they are differently affected by changes in temperature and pCO2. Thalli from Helgoland grown at 17 °C and 10 °C and from Spitsbergen at 10 °C and 4 °C were all tested at either 380, 800, or 1,500 µatm pCO2, and total C-, total N-, protein, soluble carbohydrate, and lipid content, as well as C/N-ratio were measured. At 10 °C, the Arctic population had a higher content of total C, soluble carbohydrates, and lipids, whereas the N- and protein content was lower. At the lower tested temperature, the Arctic ecotype had particularly higher contents of lipids, while content of soluble carbohydrates increased in the Helgoland population only. In Helgoland-thalli, elevated pCO2 caused a higher content of soluble carbohydrates at 17 °C but lowered the content of N and lipids and increased the C/N-ratio at 10 °C. Elevated pCO2 alone did not affect the BC of the Spitsbergen population. Conclusively, the Arctic ecotype was more resilient to increased pCO2 than the temperate one, and both ecotypes differed in their response pattern to temperature. This differential pattern is discussed in the context of the adaptation of the Arctic ecotype to low temperature and the polar night

Increased pCO2 and temperature reveal ecotypic differences in growth and photosynthetic performance of temperate and Arctic populations of Saccharina latissima

The previous research demonstrated that warming and ocean acidification (OA) affect the biochemical composition of Arctic (Spitsbergen; SP) and cold-temperate (Helgoland; HL) Saccharina latissima differently, suggesting ecotypic differentiation. This study analyses the responses to different partial pressures of CO2 (380, 800, and 1500 latm pCO2) and temperature levels (SP population: 4, 10  C; HL population: 10, 17  C) on the photophysiology (O2 production, pigment composition, D1-protein content) and carbon assimilation [Rubisco content, carbon concentrating mechanisms (CCMs), growth rate] of both ecotypes. Elevated temperatures stimulated O2 production in both populations, and also led to an increase in pigment content and a deactivation of CCMs, as indicated by 13C isotopic discrimination of algal biomass (ep) in the HL population, which was not observed in SP thalli. In general, pCO2 effects were less pronounced than temperature effects. High pCO2 deactivated CCMs in both populations and produced a decrease in the Rubisco content of HL thalli, while it was unaltered in SP population. As a result, the growth rate of the Arctic ecotype increased at elevated pCO2 and higher temperatures and it remained unchanged in the HL population. Ecotypic differentiation was revealed by a significantly higher O2 production rate and an increase in Chl a, Rubisco, and D1 protein content in SP thalli, but a lower growth rate, in comparison to the HL population. We conclude that both populations differ in their sensitivity to changing temperatures and OA and that the Arctic population is more likely to benefit from the upcoming environmental scenario than its Atlantic counterpart

El uso de recursos multimedia en la docencia de la Ecología en Ciencias Experimentales: los ecosistemas polares como caso de estudio

En este trabajo se presentan las experiencias realizadas en el seno de un proyecto de Innovación Docente financiado por el Secretariado de Innovación Docente de la Universidad de Jaén. Los objetivos planteados en dicho proyecto consistieron en acercar a los alumnos la investigación realizada en distintos campos de la Ecología en ecosistemas polares (Ártico y Antártida), así como incorporar nuevas metodologías docentes en la docencia práctica de la asignaturas relacionadas con la Ecología en las Licenciaturas de Biología y Ciencias Ambientales. Durante el desarrollo del proyecto se realizaron videoconferencias con investigadores desplazados a la Antártida, visionado de vídeos realizados durante campañas de investigación en ecosistemas polares y una mesa redonda donde se intercambiaron experiencias entre los investigadores y el alumnado, dentro del marco de las actividades de la Semana de la Ciencia 2010 organizada por la Unidad de Cultura Científica de la Universidad de Jaén, estando todas estas actividades abiertas al conjunto de la Comunidad Universitaria

Radionuclides in arctic marine macroalgae from Kongsfjorden (Svalbard)

Seaweeds are known to be useful environmental bioindicators since they bioaccumulate radioisotopes at very low environmental concentrations. Levels of natural radionuclides in six ecologically relevant brown and red seaweed species from Arctic coasts (Kongsfjorden, Spitsbergen, Svalbard Islands) were analysed in the present study, in order to characterise the levels of natural radioactivity in this ecosystem and to compare this with previously published data in coastal areas from other latitudes. Thalli were collected by SCUBA divers at different depths in Hansneset in September 2014 and transported immediately to the laboratory. Young thalli, free from macroscopic epibiota, were dried, powdered and confined in a standard geometry before gamma spectrometry measurements. Then, the radioactivity of 7Be, 40K, 208Tl, 210Pb, 212Pb, 226Ra and 228Ra was measured by high-resolution gamma spectrometry using high-purity germanium detectors for 172800 s. Detectors were calibrated using a traceable multi gamma standard source and results are on a dry weight and fresh weight basis and are decay corrected to the date of sampling. Our results revealed the influence of cosmogenic radionuclides in the intertidal zone, as shown by the unique presence of 7Be in the brown macroalga Fucus distichus, the only analysed species inhabiting the intertidal. High concentrations of 40K were observed in all species, as this is one of the essential elements in biota. Remarkably is the high content of 210Pb in the red seaweeds Phycodrys rubens and Ptilota gunneri, suggesting that these species might possess a higher capacity for heavy metals bioaccumulation than the analysed brown seaweeds

Automated detection of parenchymal changes of ischemic stroke in non-contrast computer tomography: a fuzzy approach

The detection of ischemic changes is a primary task in the interpretation of brain Computer Tomography (CT) of patients suffering from neurological disorders. Although CT can easily show these lesions, their interpretation may be difficult when the lesion is not easily recognizable. The gold standard for the detection of acute stroke is highly variable and depends on the experience of physicians. This research proposes a new method of automatic detection of parenchymal changes of ischemic stroke in Non-Contrast CT. The method identifies non-pathological cases (94 cases, 40 training, 54 test) based on the analysis of cerebral symmetry. Parenchymal changes in cases with abnormalities (20 cases) are detected by means of a contralateral analysis of brain regions. In order to facilitate the evaluation of abnormal regions, non-pathological tissues in Hounsfield Units were characterized using fuzzy logic techniques. Cases of non-pathological and stroke patients were used to discard/confirm abnormality with a sensitivity (TPR) of 91% and specificity (SPC) of 100%. Abnormal regions were evaluated and the presence of parenchymal changes was detected with a TPR of 96% and SPC of 100%. The presence of parenchymal changes of ischemic stroke was detected by the identification of tissues using fuzzy logic techniques. Because of abnormal regions are identified, the expert can prioritize the examination to a previously delimited region, decreasing the diagnostic time. The identification of tissues allows a better visualization of the region to be evaluated, helping to discard or confirm a stroke.Peer ReviewedPostprint (author's final draft

High-CO2 Levels Rather than Acidification Restrict Emiliania huxleyi Growth and Performance

The coccolithophore Emiliania huxleyi shows a variety of responses to ocean acidification (OA) and to high-CO2 concentrations, but there is still controversy on differentiating between these two factors when using different strains and culture methods. A heavily calcified type A strain isolated from the Norwegian Sea was selected and batch cultured in order to understand whether acclimation to OA was mediated mainly by CO2 or H+, and how it impacted cell growth performance, calcification, and physiological stress management. Emiliania huxleyi responded differently to each acidification method. CO2-enriched aeration (1200 µatm, pH 7.62) induced a negative effect on the cells when compared to acidification caused by decreasing pH alone (pH 7.60). The growth rates of the coccolithophore were more negatively affected by high pCO2 than by low pH without CO2 enrichment with respect to the control (400 µatm, pH 8.1). High CO2 also affected cell viability and promoted the accumulation of reactive oxygen species (ROS), which was not observed under low pH. This suggests a possible metabolic imbalance induced by high CO2 alone. In contrast, the affinity for carbon uptake was negatively affected by both low pH and high CO2. Photochemistry was only marginally affected by either acidification method when analysed by PAM fluorometry. The POC and PIC cellular quotas and the PIC:POC ratio shifted along the different phases of the cultures; consequently, calcification did not follow the same pattern observed in cell stress and growth performance. Specifically, acidification by HCl addition caused a higher proportion of severely deformed coccoliths, than CO2 enrichment. These results highlight the capacity of CO2 rather than acidification itself to generate metabolic stress, not reducing calcification.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Funding for open access charge: Universidad de Málaga / CBUA This work was funded by FC14-RNM-27 research grant (FITOVIA) from the University of Málaga, Spain (Plan Propio) to CJ. VV was funded by a EUROPE ERASMUS+grant to carry out research short-stay at Marine Scotland Marine Laboratory in Aberdeen, UK, and by a grant from the University of Málaga, Spain (Plan Propio)