This study investigated variation in xylem anatomy, hydraulic properties, and the relationship between anatomy and properties within Douglas-fir trees at multiple scales. The hierarchical scales in the study included fertilization treatments (fertilized and unfertilized), trees within the treatments, and positions within the trees. Tracheid diameter, tracheid length, percent latewood, number...
Heavy timber framing relies primarily on bracing to withstand lateral loads due to earthquakes and wind events. Bracing configurations in heavy timber framed buildings vary widely and include cross bracing, knee bracing, and other geometries. Many heavy timber frames constructed during colonial American times are still standing, exceeding the expected...
Animal signaling systems frequently utilize multiple traits to produce and transmit a signal. These system elements may span multiple levels of organization. Functional integration of these traits may be expected to generate concordance in evolutionary pattern among system elements, such that evolutionary change in one system component is correlated with...
Light-frame construction practices and materials have changed greatly
over the past 100 years. Contemporary research has focused on modern construction; thus, we know a great deal about the behavior of modern lightframe buildings under lateral forces. However, there are many light-frame buildings that were built prior to the introduction of...
Negative feedback has become ubiquitous in science both as a
technique and as a conceptual tool. As a technique, negative feedback
has a long history; devices based in its use were made in
antiquity. It has only been during the last century, however, that
rigorous quantitiative methods have become associated...
L. C. Dunn (1893-1974) spent most of his scientific career conducting research in
developmental genetics as a member of the Zoology Department at Columbia
University in the City of New York. He had an accomplished scientific career
researching mutations in mice, which earned him respect from other geneticists and
scientists....