This paper presents visibility distances from twenty people who have viewed six internally illuminated elements of emergency lighting systems or wayguidance systems, under different ambient lighting, in smoke. The optical density of the smoke ranges from 0.8 m-1 to 1.4 m-1. The six elements investigated are four emergency exit signs with graphical symbol formats and two types of exit door markings. The distance at which the elements are first visible through the smoke are reported, under no overhead lighting, emergency overhead lighting (producing between 1 and 2 lux on the floor) and normal lighting (producing between 130 and 190 lux on the floor). Statistical analysis shows that the total optical density of the smoke between the observer and sign or door marking is not significantly different between no overhead lighting and emergency overhead lighting, however both these situations allow the element to be seen through a greater total optical density than under normal overhead lighting. Significant differences between the total optical density of the smoke that the six elements can be seen through are also reported.

This paper presents the views of 16 fully sighted people who carried out typical office tasks under eight different lighting systems. This work is taken from a much larger study, primarily involved with the lighting of office tasks for visually impaired people. Non‐parametric statistical tests show there are significant differences of opinion about the different lighting systems in terms of adequacy and comfort. Whilst there is a general trend in the results which suggest that increasing task illuminance and wall illuminance is preferred by the test subjects, other issues are identified which can influence aspects of lighting quality.

Measurements are reported on the characteristics of the vortex wakes that trail from 0.03-scale models of a B-747 and a DC-10. Included are the downwash distributions obtained with a hot-film anemometer probe for the standard landing configurations, and the rolling moments induced on various following wings by the vortex wakes of several configurations of both wake-generating models. Both sets of data are presented for downstream distances of 81 and 162 ft, i.e., scale distances of 0.5 and 1.0 mile.

A successful technique for the initiation and proliferation of shoots from epicotyl tissue of soybean, Glycine max, has been developed and is described. Fertile plants were recovered. Seeds were germinated on Murashige and Skoog medium containing 5 μM benzyladenine. Explanted epicotyl sections were induced to form callus and shoots on Schenk and Hildebrandt medium containing 5.2 mM monobasic ammonium phosphate, 74 μM 3-aminopyridine, and 20 μM kinetin for five weeks. Shoot proliferation was maintained on N6 medium containing 1.75 mM ammonium sulfate, 2.1 nM picloram, and 0.1 μM benzyladenine. Shoots rooted on Gamborg's B5 medium without growth regulators. Shoot-forming cultures were maintained for 60 months. Although all varieties tested produced shoots, some variation in numbers of shoots obtained was observed.

A reproducible method for regeneration of plants from primary leaf tissue of 27 varieties of soybean (Glycine max), encompassing maturity groups 00 to VIII, has been developed. Progeny from seeds recovered from regenerated plants appear normal. Best regeneration was from leaf explants (2.1–4.0 mm) obtained from 5 day old seedlings. While 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was demonstrated to be essential for regeneration, addition of benzyladenine (BA) was found to enhance regeneration. Of the 6 other auxins tested, only picloram induced any regenerative response. Using identical volumes of medium and other conditions, regeneration could be obtained in 95 × 25 mm glass culture tubes but not in 60 × 15 mm Petri dishes.

A procedure for the regeneration of fertile plants by organogenesis from tissue cultures of soybeans, Glycine max is described. Seeds were germinated on reduced inorganic salt MS medium containing 5μM BA. Cotyledonary nodes were excised and cultured on the same medium. Presence of BA in the medium during seed germination and culture of nodal explants was required for multiple shoot and shoot-bud formation. Histological analyses established the de novo nature of shoot regeneration. Separate reduction of the concentration of inorganic salts or substitution of sucrose for fructose during culture had minimal effects on the regeneration response. Conversely, if the BA was reduced, the inhibition response could not be overcome by increased salt concentration or altered carbon source.

Wounded petiole surfaces of excised soybean (Glycine max (L.) Merr.) leaves of 'Peking' formed neoplastic growths testing positive for opines after inoculation with a tumorigenic strain of Agrobacterium tumefaciens. During the 48-h inoculation period, uninoculated explants and explants inoculated with A136 (avirulent), A208 (tumorigenic), and ASE1-200 (nontumorigenic) strains of A. tumefaciens showed initiation of mitotic activity at the wound surface conforming with classical descriptions of the wound response; however, shortly after explant transfer to tissue culture medium, morphogenetic patterns in explants inoculated with tumorigenic A. tumefaciens deviated from the uninoculated and A136 inoculated controls. This developmental deviation was correlated to the presence of the Ti plasmid in the bacterium. Explants inoculated with nontumorigenic A. tumefaciens showed a morphogenetic pattern intermediate between the controls and explants inoculated with tumorigenic bacteria. This suggests that the latter plant response might be due to a plant regulator gene found in the vir region of the Ti plasmid. Explants inoculated with tumorigenic bacteria showed decreasing efficiency of transformation if inoculations were delayed 4 h after excision and explants showed greatest thermosensitivity to transformation during the 48-h inoculation period. Reduced thermosensitivity was evident after transfer to tissue culture medium supplemented with carbenicillin. In this in vitro inoculation procedure, 'Peking' was shown to be twice as transformable as 'Corsoy 79'. This offers an opportunity to determine if there is a heritable component associated with transformation in this soybean explant system.Key words: Agrobacterium tumefaciens, Glycine, transformation, wound response, tissue culture.

J. C. Clark, J. H. Fremlin, W. Tanti-Wipawin, N. A. Dyson, A. E. Simpson, D. R. Williams, J. S. Hislop, T. J. Spinks, D. K. Bewley, B. J. Thomas, M. S. Wright, E. Ozbas, D. Vartsky, J. W. Mcmillan and T. B. Pierce, Proc. Anal. Div. Chem. Soc., 1976, 13, 193 DOI: 10.1039/AD9761300193

This paper presents results from 18 people who have passed through a smoke filled building under six types of emergency lighting. Their walking speeds are analysed to show which lighting systems allow people to walk along the route most quickly. It is shown that high mounted lighting that is similar to that called for by British Standard 5266 causes people to walk significantly slower than the tested wayguidance systems. Normal overhead lighting also causes people to walk more slowly than some of the wayguidance systems tested.