Publications by authors named "F Duennebier"

Minke whales (Balaenoptera acutorostrata) in the tropical North Pacific are elusive and difficult to detect visually. The recent association of a unique sound called the "boing" to North Pacific minke whales has made it possible to use passive acoustics to investigate the occurrence of this species in Hawaiian waters. One year of recordings (17 February 2007-18 February 2008) made at the Station ALOHA Cabled Observatory were examined to investigate the characteristics of boings and temporal patterns in their occurrence at this site, located 100 km north of Oahu.

View Article and Find Full Text PDF

Glycerophosphodiester phosphodiesterase (GDPD) catalyzes the hydrolysis of deacylated glycerophospholipids to glycerol phosphate and alcohol. A mammalian glycerophosphoinositol phosphodiesterase, GDE1/MIR16, was recently identified as an interacting protein of the regulator of G protein signaling 16 (RGS16) providing a link between phosphoinositide metabolism and G protein signal transduction. To further understand the function and properties of human GDE1, we determined its genomic organization and its biochemical and structural characteristics.

View Article and Find Full Text PDF

Both P(n), and S(n), phases recorded at distances greater than 3000 kilometers in the western Pacific have substantial amounts of energy at high frequencies, in sorne instances as high as 12 hertz for P(n) and 15 hertz for S(n), A comparison of P(n) and S(n) spectra reveals generally higher energy levels and higher proportions of high-frequency to low-frequency energy for S(n) than for P(n). Estimates of the effective quality factor, Q, indicate that the efficiency of S(n) propagation may be two or three times that of P(n). First arrivals of Pn and Sn have apparent velocities in agreement with values for the uppermost mantle, whereas maximum-energy arrivals have apparent velocities in agreement with values for the lower crust.

View Article and Find Full Text PDF

A three-axis short-period seismometer is now operating on Mars in the Utopia Planitia region. The noise background correlates well with wind gusts. Although no quakes have been detected in the first 60 days of observation, it is premature to draw any conclusions about the seismicity of Mars.

View Article and Find Full Text PDF

Seismometers on the moon have detected several brief periods of enhanc ed meteoroid-impact activity, believed to represent encounters of the moon with "c louds" of objec ts in the kilogram range. The latest and most active encounter, in June 1975, is interpreted as a meteoroid c(loud of diameter 0.1 astronomical unit and total mass 10(l3) to 10(14) grams.

View Article and Find Full Text PDF