—Observation and measurement of fibril angles in increment cores or similar small samples from living pine trees was facilitated by the use of fluorescence microscopy. Although some autofluorescence was present, brighter images could be obtained by staining the specimens with a 0.1% aqueous solution of a fluoro­ chrome (Calcozine flavine TG extra concentrated, Calcozine red 6G extra, rhodamine ...

Results of flow visualization experiments are presented to clearly identify the trigger mechanism for critical heat flux (CHF) in flow boiling. It is shown that discrete bubbles which form following the onset of nucleation coalesce into a wavy vapor layer at fluxes well below CHF. Depressions in the layer interface were observed to touch the heater surface periodically, painting a thin liquid s...

Stereomicroscope The new Carl Zeiss stereomicroscope Stemi 2000-CS allows the user to view the sample whilst other observers view the procedure by video. Greenough type stereomicroscopes create their stereo effect by having separate light paths set at different angles, one for each eye. However, when video or photomicrography is being carried out most stereomicroscope systems remove light from ...

Stereomicroscope The new Carl Zeiss stereomicroscope Stemi 2000-CS allows the user to view the sample whilst other observers view the procedure by video. Greenough type stereomicroscopes create their stereo effect by having separate light paths set at different angles, one for each eye. However, when video or photomicrography is being carried out most stereomicroscope systems remove light from ...

It was in a greenhouse in Oakland, California in 1989 that I began to question what I thought I knew about the use of transgenes in agriculture. I had been urged to look at some transgenic petunia plants by a company to which I was a scientific advisor. The plants in front of me had deep purple petals with many white segments. Some of the plants had all-white flowers. The white segments and the...

There are dozens of different myosin isozymes, though it's not clear why cells require such a diversity. These images of fluorescently-labelled hair cells from the inner ears of frog, guinea pig and mouse show the localization of actin (red at top left and bottom right) and of four different forms of myosin (green, except at bottom left, where myosin VI is labelled in red). Hair cells are the r...

What is it famous for? Being a successful, truly European research centre — still a very rare species. Early plans for EMBL were much influenced by the most famous of the species, the Conseil Européen pour la Recherche Nucleaire (CERN), and by Leo Szilard, a nuclear physicist turned molecular biologist. Where is it? About 80% of EMBL group leaders are at the main centre, on top of a beautiful b...

Development of the cotyledonary region in Chamaesyce maculata is described from germination of the seed through formation of the dense mat of branches which characterize this common weed. The cotyledonary node is trilacunar with split-lateral traces. Epicotyl development is limited to a pair ofleaves ("V-leaves") inserted directly above and decussate to the cotyledons. The two V-leaves are also...

Measurements and observations of five early events of fertilization, singly and in pairs, from single sea urchin eggs have revealed the precise temporal sequence and spatial distribution of these events. In the Arbacia punctulata egg, a wave of surface contraction occurs coincident with membrane depolarization (t = 0). These two earliest events are followed by the onset of a rapid, propagated i...

The source and sinks for the intracellular calcium released during fertilization were examined in single eggs from the sea urchin, Arbacia punctulata. Single eggs were microinjected with the calcium photoprotein, aequorin. The calcium-aequorin luminescence was measured with a microscope-photomultiplier or observed with a microscope-image intensifier-video system. In the normal egg a propagated ...