Conduction in inward rectifier, K+-channels in Aplysia neuron and Ba++ blockade of these channels were studied by rapid measurement of the membrane complex admittance in the frequency range 0.05 to 200 Hz during voltage clamps to membrane potentials in the range -90 to -40 mV. Complex ionic conductances of K+ and Cl- rectifiers were extracted from complex admittances of other membrane conductio...

The morphogenesis of the Drosophila embryonic heart tube has emerged as a valuable model system for studying cell migration, cell-cell adhesion and cell shape changes during embryonic development. One of the challenges faced in studying this structure is that the lumen of the heart tube, as well as the membrane features that are crucial to heart tube formation, are difficult to visualize in who...

475 Abstract: The pattern of distribution of fibronectin adhesins on yeast and hyphalform Candida albicans was studied with goldlabelled fibronectin and transmission electron microscopy. The germ-tube parts of the hyphal-form cells were the major binding sites for gold-labelled fibronectin, and the attached yeast-cell parts and yeast-form cell remained unlabelled. Therefore, the walls of the ge...

Tomosynthesis requires projection images from different viewing angles. Using a distributed x-ray source this can be achieved without mechanical motion of the source with the potential for faster image acquisition speed. A distributed x-ray tube has been designed and manufactured specifically for breast tomosynthesis. The x-ray tube consists of 31 field emission x-ray sources with an angular ra...

The paper presents a numerical study of the periodic self focusing behavior of a laser pulse propagation in a gas filled capillary plasma with a parabolic electron density profile. An implicit and inherently stable Crank-Nicholson method was used to demonstrate the periodic laser beam waist behavior inside the tube discharge. The dependence of the tube radius and beam waist on maximum intensity...

Two morphologically distinct types of horizontal cell have been identified in the all-rod skate retina by light- and electron-microscopy as well as after isolation by enzymatic dissociation. The external horizontal cell is more distally positioned in the retina and has a much larger cell body than does the internal horizontal cell. However, both external and internal horizontal cells extend pro...

Each of the eight 1.2 MW RF klystrons for the PEP-II storage rings require a 2.5 MVA DC power supply of 83 Kv at 23 amps. The design for the suply was based on three factors: low cost, small size to fit existing substation pads, and good protection against damage to the klystron including klystrong gun arcs. The supply uses a 12 pulse 12.5 KV primary thyristor “star point controller” with prima...