Photodynamic effect of dye on frog muscle fibre using microelectrodes

Zusammenfassung Kurarisierte und nichtkurarisierte Frosch-Sartorii zeigten einen veränderlichen Grad der Depolarisation, wenn sie mit Bengalrot (1:25 000) gefärbt und durch scharf zentriertes Licht einer 300-Watt-Tungsten-Lampe beleuchtet wurden. Die Depolarisation wurde niemals im äusseren Natrium und ohne Sauerstoff beobachtet.     

Metabolic requirements for entry of DNA inBranhamella catarrhalis

Summary Although requirements for transformation inBranhamella catarrhalis are quite complex, DNA synthesis does not appear to be one of these needs, as indicated by the inability of nalidixic acid to interefere with transformation. Exogeneous sources of energy, such as cAMP and cGMP, also failed to enhance frequency, suggesting cells may actively engage in energy production to achieve uptake of DNA, or lack a transport mechanism for these compounds.     

Metabolic requirements for entry of DNA in Branhamella catarrhalis.

Although requirements for transformation in Branhamella catarrhalis are quite complex, DNA synthesis does not appear to be one of these needs, as indicated by the inability of nalidixic acid to interefere with transformation. Exogenous sources of energy, such as cAMP and cGMP also failed to enhance frequency, suggesting cells may actively engage in energy production to achieve uptake of DNA, or lack a transport mechanism for these compounds.     

A zone of non-proliferating cells at a lineage restriction boundary in Drosophila

The use of X-ray-induced mitotic recombination to genetically mark individual cells and their descendants during development has led to the discovery of lineage restriction boundaries in Drosophila imaginal disks, dividing the disks into areas called compartments. Clones of cells initiated after a given developmental stage are unable to grow across these boundaries, even if provided with a growth rate advantage over the remaining cells. It has been suggested that cells within compartments are distinguished by the differential activation of selector genes and that the lineage restrictions are maintained by adhesivity differences between the cells in different compartments, but other mechanisms have not been ruled out. Recently a discrete population of cells with unusual permeability properties has been described along an intersegmental lineage restriction boundary in Oncopeltus, suggesting that a lineage restriction could be maintained by a zone of cells which present a barrier to clone growth. Here we demonstrate by autoradiography the presence of a narrow zone of non-proliferating cells (ZNC) coincident with the presumptive wing margin in the Drosophila wing disk, and suggest that this could account for the observed lineage restriction between presumptive dorsal and ventral surfaces of the wing. As the anterior/posterior compartment boundary does not coincide with a ZNC, the results indicate that different lineage boundaries may be maintained by different mechanisms.     

SYSTEMIC PATHOLOGIES OF CONFRONTATION： DIAGNOSING SECURITY DISRUPTION

The world post-9/11 is characterised by uncertainty, fear and suspicion. Psychological confrontations amplified by the mass media have even come to dominate physical engagements between warring parties. Drama theory provides a powerful framework for understanding these interactions in much the way that game theory was able to support strategy making by autonomous players in a less inter-connected era. A model of the ‘normal’ process leading to dramatic resolution is an essential feature of the drama theory approach and is described here. However this process can be derailed or fail in many ways. This paper reviews many of these systemic pathologies and illustrates some of them through consideration of three high-profile cases. The conclusion is that it is important to recognise and possibly to use pathological behavior as an element of a character’s interaction strategy.