In the northern Gulf of Alaska and Prince William Sound, we have used wide‐angle seismic reflection/refraction profiles, earthquake studies, and laboratory measurements of physical properties to determine the geometry of the Prince William and Yakutat terranes, the Aleutian megathrust, and the subducting Pacific plate. In this complex region, the Yakutat terrane is underthrust beneath the Prince William terrane, and both terranes are interpreted to be underlain by the Pacific plate. Wide‐angle seismic reflection/refraction profiles recorded along five seismic lines are used to unravel this terrane geometry. Modeled velocities in the upper crust of the Prince William terrane (to 18 km depth) agree closely with laboratory velocity measurements of Orca Group phyllites and quartzofeldspathic graywackes (the chief components of the Prince William terrane) to hydrostatic pressures as high as 600 MPa (6 kbar). A landward dipping reflector at depths of 16–24 km is interpreted as the base of the Prince William terrane. This reflector corresponds to the top of the Wadati‐Benioff zone seismicity and is interpreted as the megathrust. Immediately beneath the megathrust is a 4‐km‐thick 6.9‐km/s refractor, which we infer to be the source of a prominent magnetic anomaly and which is interpreted by us and previous workers to be gabbro in Eocene age oceanic crust of the underthrust Yakutat terrane. Wide‐angle seismic data, magnetic anomaly data, and tectonic reconstructions indicate that the Yakutat terrane has been underthrust beneath the Prince William terrane for at least a few hundred kilometers. Wide‐angle seismic data are consistent with a 9° to 10° landward dip of the subducting Pacific plate beneath the outer shelf and slope, distinctly different from the inferred average 3° to 4° dip of the overlying 6.9‐km/s refractor and the Wadati‐Benioff seismic zone beneath the inner shelf. Our preferred interpretation of the geophysical data is that one composite plate, composed of the Pacific plate of a fairly uniform thickness and the Yakutat plate of varying thickness, is subducting beneath southern Alaska.

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Background. One thousand seventy patients treated conservatively for Stages I and II breast cancer between the years 1982 and 1994 were reviewed. The median follow‐up was 40 months with a maximum follow‐up of 152 months. Methods. All patients had a wide local excision and lower lymph axillary node dissection followed by radiation therapy. The entire breast received an external beam dose of 4500 cGy at 180 cGy/5 days/week. An additional boost dose of 2000 cGy to the tumor bed was given at the time of lumpectomy (perioperative) with an Ir‐192 implant or with electron beam therapy after the external beam therapy. Results. The 5‐ and 10‐year disease specific survival results were 97 and 90%, respectively for Stage I and 87 and 69% for patients with Stage II disease. The 5‐ and 10‐year local control rates were 93 and 85% for Stage I and 92 and 87% for Stage II, respectively. The risk factors for local failure were premenopausal status and estrogen receptor‐negative status at the univariate level but at the multivariate level the premenopausal and margins status were significant. Conclusion. These 10‐year results were at least equivalent to reported series of similarly staged patients treated by mastectomy. This should encourage more surgeons to offer conservative treatment as an alternative to mastectomy to patients with Stage I and II breast cancer.

The purpose of this retrospective study was to examine lower extremity joint stiffness between runners with and without low back pain. We compared data from three groups: current low back pain (LBP), resolved pain (RES), and a control (CTRL) group of runners. We hypothesized that the LBP group would exhibit increased ankle, knee, and hip joint stiffness when compared with the other groups. Subjects ran on a force treadmill at 3.8 m*s(-1) while data were collected. Joint stiffness was determined from the joint moment-angle profiles. Differences were observed in knee joint stiffness, with the LBP group exhibiting the greatest stiffness values. No differences in ankle or hip joint stiffness were observed. These data suggest that the LBP group of runners may not attenuate the foot-ground impact to the same level as the other groups. The decreased attenuation may increase the level of the shock to the low back region, thus potentially increasing the load on the low back.

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