Simulating ROSAT PSPC hardness ratios HR1 and HR2 and count rates for NLTE white dwarf atmosphere spectra one finds that the 15 supersoft sources in the spiral galaxy M 31 contain hot ≈ 3.0 − 4.5 × 105 K white dwarfs. If they undergo steady nuclear burning and if they are located close to the stability line then they harbor massive white dwarfs MWD ≈ 0.85−1.0M in agreement with what has been fo...

—Hybridization with nonnative fishes is a major factor influencing the status of native catostomids in the Colorado River basin. In Wyoming, hybridization with nonnative white suckers Catostomus commersonii is a particular concern in the conservation of native bluehead suckers C. discobolus and flannelmouth suckers C. latipinnis. The purpose of this study was to describe the meristic and morpho...

BACKGROUND AND PURPOSE MR diffusion tensor imaging permits detailed visualization of white matter fiber tracts. This technique, unlike T2-weighted imaging, also provides information about fiber direction. We present findings of normal white matter fiber tract anatomy at high resolution obtained by using line scan diffusion tensor imaging. METHODS Diffusion tensor images in axial, coronal, and...

We present spectra of the DAB white dwarf PG1115+166. Radial velocity measurements of the Balmer lines and the HeI 6678Å line show that this is a binary white dwarf with a period of 30.09d in which the Balmer lines move in anti-phase to the HeI line, i.e., PG1115+166 is a DA+DB binary. The minimum masses of the stars are MDA = 0.43±0.15M⊙ and MDB = 0.52±0.12M⊙. The separation of the stars is ab...