Red tree vole Red tree vole The red tree vole ("Arborimus longicaudus") is a rodent found in Oregon and California. The red tree vole is a rodent in the family Cricetidae. It is found only in coastal forests of Oregon and northern California. They eat exclusively the needles of conifers, mostly Douglas-fir ("Pseudotsuga menziesii") and occasionally other species. They often spend their lives in just one tree, and many generations will live in different parts of the same tree. When eating Douglas-fir needles, they carefully remove the fine resin ducts (which resemble coarse, straight hairs) along each edge of the needle, discarding these
Fraser Filter Fraser Filter A Fraser Filter, named after Douglas Fraser, is typically used in geophysics when displaying VLF data. It is effectively the first derivative of the data. If formula_1 represents the collected data then formula_2 is the average of two values. Consider this value to be plotted between point 1 and point 2 and do the same with points 3 and 4: formula_3 If formula_4 represents the space between each station along the line then formula_5 is the Fraser Filter of those four values. Since formula_6 is constant, it can be ignored and the Fraser Filter considered to be formula_7.