We explore the long-term environmental and human history of a small outer coast archipelago on the Northwest Coast in western Canada. Using relative sea-level change, we reconstruct ancient landscapes to design archaeological surveys that document a rich archaeological record spanning at least 11 000 years and demonstrate the cultural centrality of this geographically marginal landscape.

Topology provides a novel means to describe branching patterns and has not been applied to fungal colonies previously. For any branched structure, various topologies are possible, and these lie between two extremes, a herringbone pattern (main axis with primary laterals) and a dichotomous pattern (highly branched system). We applied topological methods to colonies of Peronospora viciae 48 h after inoculation of Pisum sativum leaves. The methods are based on two simulations, one developed for channel networks such as found in river systems and another for biological systems. Although not a true herringbone form, the Peronospora viciae colonies have a strong herringbone element within their growth pattern. All 25 colonies analysed fell into the random distribution according to the confidence limits calculated from simulations for biological systems. These confidence limits, however, represent the percentile distribution of all simulated networks, and only those structures with a perfect herringbone or dichotomous topology fall outside the range. The tendency of P. viciae colonies towards herringbone growth is reflected by the topological indices for altitude and external pathlength (a(obs)/E(a) and pe(obs)/E(pe), where a=altitude, pe=external pathlength, obs=observed for the P. viciae colonies and E=expected values for random growth), and the slope of the regression analysis for a(obs) and pe(obs). We consider this trend as significant because it was consistent for all but one of the colonies, and implies that growth can be envisaged as an intermediate between random and herringbone topology. It is proposed that initial herringbone growth may reflect a strategy that is aimed at overcoming host resistance, achieving rapid colonisation of infected tissue and maximising the potential for nutrient acquisition. This topology would also increase the likelihood of finding a compatible mating type for reproduction between heterothallic isolates.

Until recently, the compact structure in 3C 395 could be described as follows (Simon et al. 1987):

1. (1) A bright, unresolved, flat spectrum core to the northwest. The core brightened by about 0.4 Jy between 1983.3 and 1985.4, from 0.6 Jy to 1.0 Jy.

2. (2) A moderately resolved component 15.8+/−0.2 mas to the southwest along P.A.I 18o. The position of this component relative to the core has changed by less than 0.2 mas in 6 years and the flux density of this component has remained roughly constant.

3. (3) A component which was moving rapidly away from the core towards component (2) with a proper motion of 0.64+/−0.1 mas yr−1. For 3C 395 (z=0.635), this implies (v/c)∼20c for Ho =100 km/s/Mpc and qo =0.5.

The concept is developed for a scientific space mission to survey the entire sky and to image individual sources at frequencies between 1.5 and 26.3 MHz, a frequency range over which the Earth's ionosphere transmits poorly or not at all. The required technology already exists and there are many important scientific goals which can be attained with high sensitivity, high resolution space observations at the lowest frequencies available to astronomy from within the absorbing interstellar plasma of our own Galaxy.

On 8–12 October 1981 a 5-station MkII VLBI experiment at 1660 MHz was performed using antennas at Westford, Maryland Point, Green Bank, Fort Davis, and Owens Valley. Fifteen extragalactic sources (Table 1) were observed with an average synthesized beam of roughly 10 mas. The data were processed using the NRAO correlator, globally fringe-fit, and mapped with the AIPS package. In addition to the usual self-calibration techiques, corrections were made to eliminate baseline-dependent calibration errors. Some of the sources, for example 1641+399 (3C345), display extended components not before observed at the dynamic range of the maps, which on the average is roughly 200:1.