Group items tagged

"Penguin feathers are highly modified in form and function, but there have been no fossils to inform their evolution. A giant penguin with feathers was recovered from the late Eocene (~36 million years ago) of Peru. The fossil reveals that key feathering features, including undifferentiated primary wing feathers and broad body contour feather shafts, evolved early in the penguin lineage. Analyses of fossilized color-imparting melanosomes reveal that their dimensions were similar to those of non-penguin avian taxa and that the feathering may have been predominantly gray and reddish-brown. In contrast, the dark black-brown color of extant penguin feathers is generated by large, ellipsoidal melanosomes previously unknown for birds. The nanostructure of penguin feathers was thus modified after earlier macrostructural modifications of feather shape linked to aquatic flight. "

How is global temperature regulated? An experimental representation - Simple experiments to help pupils understand how different parameters regulate temperature at the Earth's surface. Interaction at the Air-Water Interface, part 1 - A very simple experiment to demonstrate gas exchange and equilibration at the boundary layer between air and water. Pupils will also observe acidification of water due to CO2 introduced directly in the water. Interaction at the Air-Water Interface, part 2 - A second set of experiment to demonstrate gas exchange and equilibration at the boundary layer between air and water. Pupils observe a high atmospheric CO2 concentration will produce water acidification. Uptake of Carbon Dioxide from the Water by Plants - The following experiments will demonstrate the role of plants in mitigating the acidification caused when CO2 is dissolved in water. Carbon Dioxide Fertilization of Marine Microalgae (Dunalliela sp.) Cultures: Marine microalgae in different atmospheric CO2 concentration - An experiment designed to illustrate the impact of carbon dioxide on microalgal growth in the aquatic environment. Introduction to the principles of climate modelling - Working with real data in spreadsheets to create a climate model, students discover the global carbon budget and make their own predictions for the next century. Global carbon budget between 1958 and 2007 - Working with real global carbon budget data, students produce graphs to find the best representation of the data to make predictions about human CO2 emissions for the next century. This activity is also a nice application of percentages. Estimation of natural carbon sinks - Working with real global carbon budget data, students estimate how much of the CO2 emitted into the atmosphere as a result of human activities is absorbed naturally each year. How does temperature affect the solubility of CO2 en the water? - The following experiments will explore effects of water temperature on sol

"Nitrogen (N2)-fixing microorganisms (diazotrophs) are an important source of biologically available fixed N in terrestrial and aquatic ecosystems and control the productivity of oligotrophic ocean ecosystems. We found that two major groups of unicellular N2-fixing cyanobacteria (UCYN) have distinct spatial distributions that differ from those of Trichodesmium, the N2-fixing cyanobacterium previously considered to be the most important contributor to open-ocean N2 fixation. The distributions and activity of the two UCYN groups were separated as a function of depth, temperature, and water column density structure along an 8000-kilometer transect in the South Pacific Ocean. UCYN group A can be found at high abundances at substantially higher latitudes and deeper in subsurface ocean waters than Trichodesmium. These findings have implications for the geographic extent and magnitude of basin-scale oceanic N2 fixation rates. "