The formation, structure and evolution of protoplanetary discs is considered. The formation of giant planets within the environment of these models is also discussed.

During the eighteen imionths immllnediately prior to this report the authors have seen five cases of typical ruptured thoracic intervertebral discs. These have been stuidied, treated by surgery, and the resuilts, in contrast to some previous reports,' have been stufficieintly7 gratifying that it is felt they should be reported. There are a fewcharacteristic feattures w-hich mav be fotulnd of in...

Cells employ a diverse array of signaling mechanisms to establish spatial patterns during development. Nowhere is this better understood than in Drosophila, where the limbs and eyes arise from discrete epithelial sacs called imaginal discs. Molecular-genetic analyses of pattern formation have generally treated discs as single epithelial sheets. Anatomically, however, discs comprise a columnar c...

Wingless (wg) is a segment-polarity gene in Drosophila which is related to the murine proto-oncogene int1. In Drosophila embryos, wg transcription defines part of each parasegment. In situ hybridization shows that wg is also expressed in the imaginal discs which give rise to the adult during metamorphosis. Transcripts are localized in the apical cytoplasm of disc cells, and accumulate in differ...

Abscisic acid (ABA) significantly stimulated ethylene production in citrus (Citrus sinensis [L.] Osbeck, cv Shamouti orange) leaf discs. The extent of stimulation was dependent upon the concentration of ABA (0.1-1 milimolar) and the duration of treatment (15-300 minutes). Aging the discs before applying ABA increased ABA-induced ethylene production due to enhancement of both ethylene-forming en...

The light-sensing organelle of the vertebrate rod photoreceptor, the outer segment (OS), is a modified cilium containing approximately 1,000 stacked disc membranes that are densely packed with visual pigment rhodopsin. The mammalian OS is renewed every ten days; new discs are assembled at the base of the OS by a poorly understood mechanism. Our results suggest that discs are formed and matured ...

INTRODUCTION: A loss of nutrient supply has long been thought to be a major factor leading to disc degeneration and recent in vivo measurements have supported this hypothesis. Solute transport from the blood vessels through the endplate into the disc, measured by following gadolinium [1] or nitrous oxide [2] transport, has found that effective endplate permeability falls significantly in degene...

We propose a novel fully automatic approach to localize the lumbar intervertebral discs in MR images with PHOG based SVM and a probabilistic graphical model. At the local level, our method assigns a score to each pixel in target image that indicates whether it is a disc center or not. At the global level, we define a chain-like graphical model that represents the lumbar intervertebral discs and...

STUDY DESIGN In vitro ultrasound imaging of dog intervertebral discs was performed. OBJECTIVE To determine the reliability of ultrasound imaging in the detection of structural changes associated with disc pathology. SUMMARY OF BACKGROUND DATA Little work has been done to evaluate the potential applications of ultrasound in the imaging of intervertebral discs. Initial in vitro studies, howev...

Using B, R and Hα images of roughly equal-sized samples of low surface brightness (LSB) and high surface brightness (HSB) galaxies (∼40 galaxies apiece), we have explored the dependence of H II region properties on local and global disc surface brightness. We have done this by constructing co-added H II region luminosity functions (LFs) according to local and central disc surface brightness and...