Functional complementation by electroporation of human BACs into mammalian fibroblast cells

Bacterial Artificial Chromosomes (BACs) have been used to complement a metabolic defect and to transfer a drug resistance marker into mammalian cells by electroporation. The selectable markers are stable and the recipient cells have BAC DNA integrated into the chromosomes as shown by fluorescent in situ hybridization, PCR and Southern hybridization.     

The extinction of fires in aircraft jet engines — Part I,small-scale simulation of fires

Three modes of combustion are possible in an aircraft engine fire, and these have been simulated separately in a small wind tunnel.     

Transient emission and generation currents in Metal-Insulator-Semiconductor capacitors

The transient current of an MIS (metal-insulator-silicon) capacitor which is subjected to a voltage step (or pulse) has been investigated. It is shown that the different magnitudes and shapes exhibited by the transient current depend on the initial and final biasing conditions. By varying these conditions the three main contributing current components, namely, surface emission, surface generation and bulk generation can be identified.     

The exotoxin of Bacillus thuringiensis: a new C-mitotic agent

Thuringiensin A, an exotoxin from Bacillus thuringiensis, a constituent of the microbial insectide thuricide has been found to inhibit mitotic spindle, condense and scatter chromosomes. It may therefore be a promizing tool in future cell biological studies.     

Theory of dynamic charge current and capacitance characteristics in MIS systems containing distributed surface traps

Theoretical studies have been made on the dynamic characteristics of the metal-insulator-semiconductor (MIS) capacitor containing distributed surface traps. It has been shown that when the surface traps are in dynamic equilibrium with the voltage ramp, the device exhibits steady-state charge, current and capacitance characteristics. When the surface traps are out of equilibrium with the voltage ramp, then the emission of trapped charge is a function of time only and not of voltage. Under such conditions, the characteristics are considered to be non-steady-state in nature.In the steady state, the emission of electrons from a continuum of surface traps accounts for the reduction in the slopes of the C–V curves from the ideal ones. Kinks are manifested when the traps just empty the last of their electrons.In the non-steady state, electron emission can be described by the non-steady-state (time-dependent) occupancy function derived herein, which is shown to be similar in shape to the Fermi function. This means that electron emission takes place from a narrow band of energy positioned near the uppermost-filled traps. Hysteresis effects are manifested in the C–V characteristics due to the non-steady-state emission of trapped charge. At the transition from the steady state to the non-steady state and vice versa, kinks are exhibited in the charge and capacitance characteristics, while step changes in current components are also predicted.The physical processes involved have been stressed and closed-form expressions have been obtained for the charge, current and capacitance in terms of the trapping parameters, sweep-rate and temperature.     

Automation in American libraries

Despite its concentration on technical developments in library science, this survey is offered here because it is relevant to humanists for two reasons: first, that humanists all use libraries and therefore need to encourage their evolution to higher levels of efficiency, and, second, that the procedures outlined here may be of help to humanists in establishing procedures for their own research.