15,110 research outputs found
Effect of increased CO<sub>2</sub> and iron levels on the marine plankton food web during a mesocosm experiment
A mesocosm experiment was carried out in the Raunefjord (Norway) during 25 days, to investigate the interactive effects of increased CO2 and iron availability on the plankton community. The seawater carbonate system in the mesocosms was manipulated to achieve two different CO2 levels, corresponding to the present (390 ppmv, LC) and to levels predicted for year 2100 (900 ppmv, HC), in combination with ambient and increased dissolved Fe (dFe) concentrations in a full factorial design. We observed a shift in the plankton community structure, initially dominated by picoeukaryotes and small nanoeukaryotes, changing to an Emiliania huxleyi dominated bloom. E. huxleyi and Synechococcus were the most sensitive organisms to changes in CO2 and Fe levels, being negatively affected by increased CO2 and favoured by high dFe levels. Picoeukaryotes, large nanoplankton, viruses and ciliates abundances were not affected by changes in CO2 or dFe levels. Bacterial abundance showed a significant positive response to high CO2 but it was unaffected by dFe. Total mesozooplankton abundances did not change significantly. The relevance of these results within the global change scenario will be discussed.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tech
Strong diquark correlations inside the proton
Quantum Chromodynamics is thought to be the relativistic quantum field theory
that describes the strong interaction of the Standard Model. This interaction
produces mesons but it is also able to generate quark-quark (diquark)
correlations inside baryons. In this work, we employ a continuum approach to
QCD based on Dyson-Schwinger equations to calculate the electromagnetic form
factors of the proton and analyze in a deeper way the consequences of having
strong diquark correlations. Comparison with the experimental data reveals that
the presence of strong diquark correlations within the proton is sufficient to
understand empirical extractions of the flavour-separated form factors. The
explained reduction of the ratios and
at high in the quark-diquark picture are
responsible of the precocious scaling of the observed
experimentally.Comment: To be published in the proceedings of 21st International Conference
on Few-Body Problems in Physics, Chicago, IL, 18-22 May 201
Multifrequency and multifunction antennas based on single printed technology partially filled with metamaterial structures
The Radiofrequency Group from the Escuela Politécnica Superior of the Carlos III University from Madrid have been working in printed antennas for a long time. Recently the new technology of metamaterials has opened new possibilities in the development of multifrequency antennas with different radiation patterns to be used simultaneously for several applications (i.e. different mobile services and GPS or Galileo
Implementation of space satellite remote sensing programs in developing countries (Ecuador)
The current state of space satellite remote sensing programs in developing countries is discussed. Sensors being utilized and results obtained are described. Requirements are presented for the research of resources in developing countries. It is recommended that a work procedure be developed for the use of satellite remote sensing data tailored to the necessities of the different countries
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