منابع مشابه
Initial Experience with the Coaxial Dual-Lumen Ascent Balloon Catheter for Wide-Neck Aneurysm Coil Embolization
INTRODUCTION Techniques for coil embolization of wide-neck cerebral aneurysms include the use of stents and temporary occlusion with compliant non-detachable balloons to safely allow dense packing of the aneurysm lumen with detachable coils. We describe the use of a new balloon device for assisting in wide-neck aneurysm coil treatment. METHODS A single institution neuroendovascular database w...
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Dynamical systems that describe the escape from the basins of attraction of stable invariant sets are presented and analysed. It is shown that the stable fixed points of such dynamical systems are the index-1 saddle points. Generalizations to high index saddle points are discussed. Both gradient and non-gradient systems are considered. Preliminary results on the nature of the dynamical behaviou...
متن کاملThe Ascent of the Senior Entrepreneur
Self-employment is increasing among seniors. The percentage of individuals age 62 and over who were self-employed increased from 4.2 percent in 1988 to 5.4 percent in 2015. In contrast, the percentage of individuals under age 62 who were self-employed decreased from 7.2 percent in 1988 to 6.0 percent in 2015. This report explains the increase in self-employment among individuals age 62 and over...
متن کاملRecursive Ascent-Descent Parsing
Generalized left-corner parsing was originally presented as a technique for generating a parser for the SLR(1) class of grammars but with far fewer states than the SLR(1) parser. This paper modi es and extends the formulation of left-corner parsers so that it is possible to apply the technique to the LALR(1) and LR(1) classes of grammars. It is further shown that left-corner parsers can be conv...
متن کاملThe Highest - Energy Cosmic Rays
The unexpected discovery of the cosmic microwave background by Arno Penzias and Robert Wilson in 1965 is now the centerpiece of our understanding of the Big Bang and the subsequent evolution of the universe. (See PHYSICS TODAY, November 1997, page 32.) The discovery also set off something of a race to verify one of its implications for cosmic rays. In 1966, Kenneth Greisen (Cornell University) ...
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ژورنال
عنوان ژورنال: Science
سال: 1908
ISSN: 0036-8075,1095-9203
DOI: 10.1126/science.28.715.343