Phase equilibria studies of Cu-O-Si systems in equilibrium with air and metallic copper and Cu-Me-O-Si systems (Me = Ca, Mg, Al, and Fe) in equilibrium with metallic copper

The pseudo-binary phase diagrams in the Cu-O-Si system in equilibrium with air and metallic copper have been constructed. Equilibration at high temperature in an appropriate containment material, followed by rapid quenching and measurement of phase compositions using an electron probe x-ray microanalysis (EPMA) technique, was carried out to obtain the phase equilibria data. The investigation has been extended to characterize the effects of CaO, MgO, AlO, and ‘‘FeO’’ on the liquidus isotherms of tridymite in equilibrium with metallic copper at temperatures of 1473 K and 1573 K (1200 °C and 1300 °C)

Diurnal transcript profiling of the diatom Seminavis robusta

Coastal regions contribute an estimated 20% of annual gross primary production in the oceans, despite occupying only 0.03% of their surface area. Diatoms frequently dominate coastal sediments, where they experience large variations in light regime resulting from the interplay of diurnal and tidal cycles. Here, we report on an extensive diurnal transcript profiling experiment of the motile benthic diatom Seminavis robusta. Nearly 90% (23 328) of expressed protein-coding genes and 66.9% (1124) of expressed long intergenic non-coding RNAs showed significant expression oscillations and are predominantly phasing at night with a periodicity of 24 h. Phylostratigraphic analysis found that rhythmic genes are enriched in highly conserved genes, while diatom-specific genes are predominantly associated with midnight expression. Integration of genetic and physiological cell cycle markers with silica depletion data revealed potential new silica cell wall-associated gene families specific to diatoms. Additionally, we observed 1752 genes with a remarkable semidiurnal (12-h) periodicity, while the expansion of putative circadian transcription factors may reflect adaptations to cope with highly unpredictable external conditions. Taken together, our results provide new insights into the adaptations of diatoms to the benthic environment and serve as a valuable resource for the study of diurnal regulation in photosynthetic eukaryotes