Common Gull Movements Shown by Ringing Returns

Identifying common dynamic features in stock returns

This paper proposes volatility and spectral based methods for cluster analysis of stock returns. Using the information about both the estimated parameters in the threshold GARCH (or TGARCH) equation and the periodogram of the squared returns, we compute a distance matrix for the stock returns. Clusters are formed by looking to the hierarchical structure tree (or dendrogram) and the computed pri...

Heliotropic leaf movements in common beans controlled by air temperature.

Heliotropic leaf movements were examined in common beans (Phaseolus vulgaris cv Blue Lake Bush) under outdoor and laboratory conditions. Heliotropic leaf movements in well-watered plants were partly controlled by temperature, and appeared to be independent of atmospheric humidity and CO(2) concentration. When environmental conditions were held constant in the laboratory, increased air temperatu...

Ringing the changes

Ringing Js refinements

Both the four-point and the uniform cubic B-spline refinement (i.e. subdivision) schemes double the number of vertices of a closed-loop polygonal curve P and respectively produce sequences of vertices fk and bk. The Js refinement proposed here produces vertices vk=(1–s)fk+sbk. Iterative applications of Js yield a family of curves parameterized by s. It includes the four-point curve (J0), the un...

Exploring plasticity in the wild: laying date-temperature reaction norms in the common gull Larus canus.

Exploration of causal components of plasticity is important for insight into evolutionary dynamics and an organism's ability to respond to climate change. Among individuals, variation in plasticity can be due to genotype-environment interaction (GxE) or a result from environmental effects associated with an individual. We investigated plasticity for laying date in the common gulls Larus canus, ...