Temperature Modulates Coccolithophorid Sensitivity of Growth, Photosynthesis and Calcification to Increasing Seawater pCO2

Increasing atmospheric CO2 concentrations are expected to impact pelagic ecosystem functioning in the near future by driving ocean warming and acidification. While numerous studies have investigated impacts of rising temperature and seawater acidification on planktonic organisms separately, little is presently known on their combined effects. To test for possible synergistic effects we exposed two coccolithophore species, Emiliania huxleyi and Gephyrocapsa oceanica, to a CO2 gradient ranging from ,0.5–250 mmol kg21 (i.e. ,20–6000 matm pCO2) at three different temperatures (i.e. 10, 15, 20uC for E. huxleyi and 15, 20, 25uC for G. oceanica). Both species showed CO2-dependent optimum-curve responses for growth, photosynthesis and calcification rates at all temperatures. Increased temperature generally enhanced growth and production rates and modified sensitivities of metabolic processes to increasing CO2. CO2 optimum concentrations for growth, calcification, and organic carbon fixation rates were only marginally influenced from low to intermediate temperatures. However, there was a clear optimum shift towards higher CO2 concentrations from intermediate to high temperatures in both species. Our results demonstrate that the CO2 concentration where optimum growth, calcification and carbon fixation rates occur is modulated by temperature. Thus, the response of a coccolithophore strain to ocean acidification at a given temperature can be negative, neutral or positive depending on that strain’s temperature optimum. This emphasizes that the cellular responses of coccolithophores to ocean acidification can only be judged accurately when interpreted in the proper eco-physiological context of a given strain or species. Addressing the synergistic effects of changing carbonate chemistry and temperature is an essential step when assessing the success of coccolithophores in the future ocean

Anales del III Congreso Internacional de Vivienda y Ciudad "Debate en torno a la nueva agenda urbana"

Acta de congresoEl III Congreso Internacional de Vivienda y Ciudad “Debates en torno a la NUEVa Agenda Urbana”, ha sido una apuesta de alto compromiso por acercar los debates centrales y urgentes que tensionan el pleno ejercicio del derecho a la ciudad. Para ello las instituciones organizadoras (INVIHAB –Instituto de Investigación de Vivienda y Hábitat y MGyDH-Maestría en Gestión y Desarrollo Habitacional-1), hemos convidado un espacio que se concretó con potencia en un debate transdisciplinario. Convocó a intelectuales de prestigio internacional, investigadores, académicos y gestores estatales, y en una metodología de innovación articuló las voces académicas con las de las organizaciones sociales y/o barriales en el Foro de las Organizaciones Sociales que tuvo su espacio propio para dar voz a quienes están trabajando en los desafíos para garantizar los derechos a la vivienda y los bienes urbanos en nuestras ciudades del Siglo XXI

Neritic planktic foraminiferal communities in the SE Bay of Biscay: influence of the Capbreton Canyon and the Adour river plume

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Towards efficient NFA-based selective near-infrared organic photodetectors: impact of thermal annealing of polymer blends

International audienceFor wavelength-selective photodetection or color discrimination, organic photodetectors (OPDs) can provide significant advantages as solution processability, chemical versatility and functionality. To eliminate the need for commonly used filters, the development of a narrowing approach that simultaneously achieves a selective detection range of less than 50 nm bandwidth and a spectral response greater than 20%, especially for wavelengths designed in the near-infrared, remains a real challenge. Herein, we demonstrate a bulk-heterojunction (BHJ) organic blend exhibiting a filter-free visible-blind near-infrared light responsive characteristic. An indacenodithienothiophene-based non-fullerene acceptor (NFA) of the ITIC family incorporating fluorine atoms, namely ITIC-4F, is mixed with PM6 donor polymer to form ultra-thick active layers in OPDs. A systematic comparison between inverted versus normal architectures was performed using different pairs of hole and electron extraction layer materials. Depending on the thermal annealing temperature of PM6:ITIC-4F blends (from 100 °C up to 200 °C), distinct light responses were observed. While the spectral response of normal structures changes from narrow to broadband with the temperature, inverted structures improve their spectral tuning. A detailed analysis of structure and morphology of blends upon thermal annealing was performed by atomic force microscopy (AFM), contact water angle (CWA) measurement, Raman analysis and 2D grazing-incidence X-ray diffractometry (2D-GIXRD). The transport properties of electrons and holes were further investigated in blends following a Space-Charge-Limited current (SCLC) protocol. We found a marked misbalance between hole and electron mobility values at 200 °C together with highly crystalline films. As a result, the optimized OPD exhibits a high-selective spectral response following the charge collection narrowing (CCN) principle with an external narrowband quantum efficiency of 24.5% and a bandwidth of 42 nm centered at 807 nm. A specific detectivity as high as ∼6 × 1012 Jones is also achieved due to a low dark current density

Oceanic versus continental influences over the last 7 kyrs from a mid-shelf record in the northern Bay of Biscay (NE Atlantic)

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