Shawn Johnson

Bottlenose dolphins can have iron overload (that is, hemochromatosis), and managed populations of dolphins may be more susceptible to this disease than are wild dolphins. Serum iron, total iron-binding capacity (TIBC), transferrin saturation, and ferritin were measured in 181 samples from 141 dolphins in 2 managed collections and 2 free-ranging populations. Although no iron indices increased with age among free-ranging dolphins, ferritin increased with age in managed collections. Dolphins from managed collections had higher iron, ferritin, and transferrin saturation values than did free-ranging dolphins. Dolphins with high serum iron (exceeding 300 μg/dL) were more likely to have elevated ferritin but not ceruloplasmin or haptoglobin, demonstrating that high serum levels of iron are due to a true increase in total body iron. A time-series study of 4 dolphins with hemochromatosis that were treated with phlebotomy demonstrated significant decreases in serum ferritin, iron, and TIBC be...

Acoustic demonstrations for the iPod generation. [The Journal of the Acoustical Society of America 127, 1912 (2010)]. Shawn F. Johnson, Juan I. Arvelo. Abstract. Today's “iPod generation” can gain a unique and interactive exposure ...

Concentrically braced frames (CBFs) are desirable for seismic design. They are stiff and strong for preventing damage during small, frequent events, but Special CBFs (SCBFs) dissipate energy during severe, infrequent earthquakes through tensile yielding and post buckling inelastic deformation. Brace buckling places significant force and deformation demands on the brace-beam-column gusset plate connections. Variations of the AISC Uniform Force Method

Adult male and female northern fur seals (Callorhinus ursinus) are sexually segregated in different regions of the North Pacific Ocean and Bering Sea during their winter migration. Explanations for this involve interplay between physiology, predator-prey dynamics, and ecosystem characteristics, however possible mechanisms lack empirical support. To investigate factors influencing the winter ecology of both sexes, we deployed five satellite-linked conductivity, temperature, and depth data loggers on adult males, and six satellite-linked depth data loggers and four satellite transmitters on adult females from St. Paul Island (Bering Sea, Alaska, USA) in October 2009. Males and females migrated to different regions of the North Pacific Ocean: males wintered in the Bering Sea and northern North Pacific Ocean, while females migrated to the Gulf of Alaska and California Current. Horizontal and vertical movement behaviors of both sexes were influenced by wind speed, season, light (sun and ...

Observations from daily experiences reveal that sound propagation in air is influenced by the ground topography, atmospheric stratification, winds, and turbulences. A ray‐based outdoor loudspeaker coverage model was developed that accounts for terrain and atmospheric ...

Paecilomyces variotii is a common cosmopolitan species that is able to spoil various food-and feedstuffs and is frequently encountered in heat-treated products. However, isolates from heat-treated products rarely form ascospores. In this study we examined by using ...

Current design practices use a strength-based design approach to design gusset plate connections in special concentrically braced frames (SCBFs), in which the expected tensile and compressive capacities of the brace are used to design the gusset plate and the weld used to connect ...