Optical fiber imaging for high speed plasma motion diagnostics: applied to low voltage circuit breakers

An integrated portable measurement system is described for the study of high speed and high temperature unsteady plasma flows such as those found in the vicinity of high current switching arcs. An array of optical fibers allows the formation of low spatial resolution images, with a maximum capture rate of 1×106 images per second (1 MHz), with 8 bit intensity resolution. Novel software techniques are reported to allow imaging of the arc; and to measure arc trajectories. Results are presented on high current (2 kA) discharge events in a model test fixture and on the application to a commercial low voltage circuit breaker

Lily regenerative callus and cell cultures for transformation

Callus cultures were established from different lily types (Easter lily and Oriental hybrids). Pistils and flower pedicels were incubated on MS-medium supplemented with 2,4-D, NAA, dicamba or picloram in various concentrations. ‘Star Gazer’ and ‘Snow Queen’ formed callus easily on medium with dicamba picloram or. Friable calli clumps of ‘Snow Queen’ were suspended in liquid medium. The resulting suspension consisted of small cell aggregates rather than loose cells and the presence of embryo like structures (ELS) was noticed. On solidified media, with and without plant growth regulators, germination of ELS was checked. Plant regeneration occurred on NAA and hormone-free media. Gene transfer experiments with the particle deliver system were carried out in order to compare the activity of CaMV 35S, rice Actine and maize Ubiquitin promoters in suspension callus and cell cultures of Easter lily ‘Snow Queen’. To this goal constructs harbouring the gus reporter gene were used. -glucuronidase expression was studied and the three promoters were found to be active in suspension cultured calli clumps and cells

Leaf physiological and anatomical responses of Lantana and Ligustrum species under different water availability

Understanding the plant characteristics that support tolerance to water stress is important in choosing plants in arid or semi-arid environments, such as the Mediterranean. In particular, leaf characteristics can affect the response of plants to water stress. In order to understand how plants with different leaf features can overcome water stress, four water regimes were adopted on two species that are widespread in the Mediterranean environment, Lantana camara and Ligustrum lucidum. The four treatments were: control (C), in which the pot substrate moisture was maintained close to water container capacity (WCC), light deficit irrigation (LDI) irrigated at 75% of WCC, moderate deficit irrigation (MDI) at 50% of WCC, and severe deficit irrigation (SDI) at 25% of WCC. To better understand the action mechanisms, the trial was repeated twice (from January to May, and from May to September). Morphological, anatomical and physiological data were measured to identify the action mechanisms. Water deficit significantly decreased the biomass accumulation in both species during the experimental growth period. In Lantana, significant variations in total leaf area and leaf number were registered between C and SDI, while in Ligustrum, the differences were significant only for total leaf area. The water deficit treatments reduced the leaf thickness especially in Ligustrum. In both species, photosynthesis reduction was related to stomatal closure. Ligustrum showed a higher variability among treatments indicating a faster and more efficient response to water limitations compared to Lantana, as also demonstrated by the lower biomass reduction in the most severe water stress treatment

Somatic embryogenesis and plant regeneration in Lilium longiflorum Thunb

Friable callus was obtained from styles and flower pedicels of Lilium longiflorum Snow Queen and the Oriental lily hybrid Star Gazer on Murashige and Skoog (MS) media containing either 2 μM dicamba or 2 μM picloram. Cell suspension cultures were established by suspending the callus of L. longiflorum Snow Queen in liquid medium containing 2 μM dicamba. Through a purification process, a fine fast-growing cell suspension was obtained. This suspension was composed of a homogenous population of small dense cells, which tended to organise into embryo like structures (ELS). In liquid culture with the auxin dicamba, the ELS underwent continuous callus formation. When transferred to solidified hormone-free MS medium, the ELS germinated, forming complete plantlets. Histological investigation showed that in the ELS both shoot and root meristems were distinctly evident. It was concluded that the ELS obtained were in fact somatic embryos

Somatic embryogenesis and plant regeneration in Lilium longiflorum Thunb

Friable callus was obtained from styles and flower pedicels of Lilium longiflorum Snow Queen and the Oriental lily hybrid Star Gazer on Murashige and Skoog (MS) media containing either 2 μM dicamba or 2 μM picloram. Cell suspension cultures were established by suspending the callus of L. longiflorum Snow Queen in liquid medium containing 2 μM dicamba. Through a purification process, a fine fast-growing cell suspension was obtained. This suspension was composed of a homogenous population of small dense cells, which tended to organise into embryo like structures (ELS). In liquid culture with the auxin dicamba, the ELS underwent continuous callus formation. When transferred to solidified hormone-free MS medium, the ELS germinated, forming complete plantlets. Histological investigation showed that in the ELS both shoot and root meristems were distinctly evident. It was concluded that the ELS obtained were in fact somatic embryos