We investigate the importance of the far red wing of the Lyman α line of hydrogen in the atmospheres of cool white dwarfs of pure hydrogen composition. We find that this absorption process dominates all important sources of opacity in the blue part of the optical spectrum of these stars. Our successful fits to the spectra of cool DA/DC white dwarfs indicate that the far red wing of the Ly α lin...

Myotonic dystrophy types 1 and 2 are progressive multisystemic disorders with potential brain involvement. We compared 22 myotonic dystrophy type 1 and 22 myotonic dystrophy type 2 clinically and neuropsychologically well-characterized patients and a corresponding healthy control group using structural brain magnetic resonance imaging at 3 T (T(1)/T(2)/diffusion-weighted). Voxel-based morphomet...

I n the play Art by Yasmina Reza, the main character puts his friendship with 2 others at risk when he purchases a piece of modern art that consists of a large white canvas with barely visible fine diagonal white lines. 1 One of his friends attempts to explain the work to the unconvinced third. " Imagine a canvas about five foot by four…with a white background…completely white in fact…with fine...

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...

white bean (phaseolus vulgaris l.) is an important legume food crop in iran and many other countries. it is grown on 110248 hectares in iran, mostly in fars, lorestan, markazi, zanjan and chahar mahal-va-bakhtiari provinces. due to its high value in human nutrition and exportation, considering that most grown cultivars of iran are the runner type beans, with low marketability values and suscept...

Metals in the photospheres of white dwarfs with Teff between 12,000 and 25,000 K should gravitationally settle out of these atmospheres in 1–2 weeks. Temporal variations in the line strengths of these metals could provide a direct measurement of episodic metal accretion. Using archival VLT and Keck spectroscopy, we find evidence that the DAZd white dwarf G29-38 shows significant changes in its ...

Metals in the photospheres of white dwarfs with Teff between 12,000 and 25,000 K should gravitationally settle out of these atmospheres in 1–2 weeks. Temporal variations in the line strengths of these metals could provide a direct measurement of episodic metal accretion. Using archival VLT and Keck spectroscopy, we find evidence that the DAZd white dwarf G29-38 shows significant changes in its ...

Metals in the photospheres of white dwarfs with TeA between 12,000 and 25,000 K should gravitationally settle out of these atmospheres in 1Y2 weeks. Temporal variations in the line strengths of these metals could provide a direct measurement of episodic metal accretion. Using archival VLTand Keck spectroscopy, we find evidence that the DAZd white dwarf G29-38 shows significant changes in its Ca...

The sharp Hα NLTE line cores of hydrogen rich (DA) white dwarfs allow their projected rotational velocities to be determined. High resolution optical spectra of 22 stars obtained with the Keck I telescope are matched by synthetic spectra computed from a grid of NLTE model atmospheres. We concentrate preferentially on hydrogen-rich white dwarfs with convective atmospheres, i.e. with Teff < 14 00...