Oh tannenbaum

Sweet! We got our tree today. For Christmas Day, we bought James the battery powered train that we'll make go around the tree for Alden. Isaac will enjoy the lights, and he gets lots of presents, too. Unfortuneately, I have to load the mass spec early, early, early Christmas morning, but I'll be back before they wake up. Sometimes my dissertation bothers me...

Speaking of... Finally began making isotopic maps of cactus. For any of you who are interested, here is a figure for you. This shows three cross sections of two saguaro Cacti. These are contour maps of del18O in stem water in August. There are three kinds of Oxygen, 16O, 17O and 18O. The 18Oxygen has two more neutrons than the 16O, so it makes water "Heavier". 18Oxygen rich water acts differently in nature (it's harder to evaporate, less likely to participate in chemical reactions, etc....a real downer). The two panels at left are from a "spiked" plant (we irrigated it with relatively light, more negative (blue) water from Idaho) and on the right is a cactus watered with regular Tucson water (more positive). As you can see, the spike is on its way up the spike plant, while on the right, you can see the effect that ribs have in partitioning the cortex (outside) of the plant from the pith (center) of the plant. Overall, evaporation makes the water "heavier" as it travels up the plant (more enriched in 18Oxygen). Now, if I could just find a way to model it....