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Coccolithophore were collected and analyzed at 10 stations during summer 2010, from coastal and offshore areas off the eastern Libyan coast (southern Mediterranean Sea). The results were compared with oceanographic data. Total coccosphere concentrations, associated with nutrient-depleted stratified waters, show good correlation with the summer data from the central and eastern Mediterranean sites. K-strategist taxa dominate the surface/intermediate water, while Florisphaera profunda is more abundant in the deep photic zone. The canonical correlation analysis reveals that the distribution of coccolithophore taxa is influenced by environmental parameters: K-strategist taxa are related to nutrient-depleted surface/intermediate waters, whereas lower photic zone taxa are influenced by the development of a deep chlorophyll maximum and high salinity values, well below the thermocline. Finally, the occurrence of three clusters above 50 m, between 50 and 100 m, and below 100 m depth can be detected. These results confirm that a vertical species zonation, as a typical feature of low-middle latitude, characterizes the eastern Libyan coast, where the holococcolithophores represent one of the most important features of coccolithophore production during summer. The distribution of F. profunda matches the depth of the DCM layer, once again confirming its use as a proxy of DCM development and paleoproductivity estimates. [ABSTRACT FROM AUTHOR]

The effect of taurine on the Na, K, Cl concentration and distribution in epithelial and compact layers of the human amniotic membrane had been investigated using the Bordeaux nuclear microprobe. Particle induced X-ray emission and Rutherford backscattering spectrometry techniques had been used to provice quantitative measurements. In physiological medium, the monovalent ions concentrations were identical in epithelial and compact layers. The addition of taurine in Hanks' physiological fluid had no effect on Na concentration, but decreased K and Cl concentration in both layers. The quantitative results were related to electrophysiological observations on the effect of taurine on ionic exchanges through channels and paracellular pathways. [ABSTRACT FROM AUTHOR]

The preventive effect of taurine towards the acute ethanol reduction action was studied on the ionic transfer through the isolated human amniotic membrane. Taurine increased 3 components of the ionic transfer expressed by the conductance measurements (Na and K paracellular conductances through the intercellular spaces and coupling cell factor between 2 adjacent epithelial cells, expressed by a voltage ratio). These components were decreased by ethanol. Electrophysiological studies (conductance and voltage measurements) indicated that the addition of taurine (0.1-1 mM) before ethanol (0.4 g/l) hindered the decrease action of ethanol on the Na and K paracellular conductances and on the coupling cell factor. These data indicated a common target between taurine and ethanol: the membraneous phospholipids, particularly the distribution of the external fixed charges. The preventive action of taurine versus ethanol, on the human amniotic membrane, was exerted on the polar groups of phospholipids, hindering the incorporation of ethanol molecules. [ABSTRACT FROM AUTHOR]

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