MORE THAN twenty years ago, the author (Gutenberg, 1926) pointed out that the longitudinal waves of shallow earthquakes decrease considerably in amplitude at epicentral distances between a few (say 2) degrees and about 15 degrees. At greater distances the amplitudes become again rather large, at 16 ° epicentral distance about as large as at 2 °. With further increase in epicentral distance the ...

The mantle wedge of a subduction zone is characterized by low seismic velocities and high attenuation, indicative of temperatures approaching the solidus and the possible presence of melt and volatiles. Tomographic images show a low velocity region above the slab extending from 150 km depth up to the volcanic front. The low velocities result at least partially from volatiles fluxed off the slab...

Dehydration of ethanol via adsorption on 3Å molecular sieves has recently been increasing in application in industry as an alternative to the conventional separation techniques for breaking the ethanol-water azeotrope. Over the past 20 years, Pressure-Vacuum Swing Adsorption (PSA) processes have gained increasing commercial acceptance as an energy-efficient separation technique. A general purpo...

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Neural circuits transmit information through synapses, and the efficiency of synaptic transmission is closely related to the density of presynaptic active zones, where synaptic vesicles are released. The goal of this review is to highlight recent insights into the molecular mechanisms that control the number of active zones per presynaptic terminal (active zone density) during developmental and...

The active zone is a unique presynaptic membrane specialization that is believed to be the site of neurotransmitter release. To examine directly the relationship between active zone ultrastructure and synaptic efficacy, frog neuromuscular junctions were studied with a new technique combining electrophysiology, light microscopy, and freeze-fracture of identified single muscle fibers. This techni...

We calculated the median values of the following parameters for 87 groups of galaxies with three to eight components: the mean rms velocity of the galaxies in the group, Sv = 166 km/s; the harmonic mean radius, Rh = 29 kpc; and the mass-to-light ratio, Mvir/L = 33M⊙/L⊙. The Mvir/L ratio depends on the population of the system, while Sv does not depend on Rh. To ascertain the relationship betwee...

Active zone proteins play a fundamental role in regulating neurotransmitter release and defining release sites. The functional roles of active zone components are beginning to be elucidated; however, the mechanisms of active zone protein localization are unknown. Studies have shown that glutamine, leucine, lysine, and serine-rich protein (ELKS), a recently defined member of the active zone comp...

To increase the detection sensitivity of capillary electrophoresis (CE) and thereby widen its application to biomolecular analyses, we have developed a number of on-line preconcentration strategies, i.e., techniques to increase sample loading without compromising resolution and efficiency. Two such techniques, namely, dynamic pH junction and field-enhanced sample injection (FESI) are covered in...