Work on short-rotation coppice willow as an alternative and renewable energy source began in Northern Ireland in the mid-1970s, prompted by the massive rise in oil prices during that period. Although in the short run oil prices have dropped in real terms, interest in short-rotation coppice willow has ben sustained because of the potential role it has in the development of agriculture, particularly in marginal areas. This is particularly relevant in the current situation of over production of a wide range of agricultural commodities within the European Community and the moves to reduce Government support in the form of farm and export subsidies.

Although Salix cultivars have yielded in excess of 30 tonnes dry matter (DM) ha−1 annually under experimental conditions, it is considered that 10–12 tonnes DM ha−1 is a sustainable commercial yield.

Melampsora spp. rust has emerged as one of the most important factors limiting the development of short-rotation coppice as a commercial crop. For economic and environmental reasons, the application of fungicide for rust control is not a possibility. Consequently, other disease control strategies have to be established. The main focus of this work is in the selection, for suitability for coppice application, of the widening range of genetic material becoming available from breeding programmes in Canada, Sweden and Finland with a view to their incorporation into mixed stands.

End product utilisation is considered a priority area for investigation if short-rotation coppice is to make a contribution to land use and the development of agriculture in marginal areas. Currently two potential end uses are being investigated: firstly fractionation – to produce cellulose for paper manufacture, hemi-cellulose for the production of molasses and lignin for further processing into other industrial chemicals, and secondly the simultaneous generation of heat and power using gasification – ‘combined heat and power’.

The breast can be deprived of oestrogen by blockade of the synthesis of oestradiol or of its precursors. In postmenopausal women, oestrogen synthesis occurs almost exclusively in extraglandular tissues. Thus, liver, muscle and fat, as well as other tissues, convert precursor androgens such as androstenedione and testosterone of adrenal origin to oestrone and oestradiol through the enzyme, aromatase. Breast cancer tissue and its surrounding stroma also contain aromatase which could potentially convert a biologically important amount of androgen to oestrogen. Sulphatases are present in multiple tissues including breast and act to reform free oestrogens from their conjugated derivatives. Each of the steps outlined (i.e. precursor androgen formation, aromatase, and sulphatase), serve as potential sites of blockade of oestrogen synthesis. Aromatase can be inhibited by either suicide or competitive inhibitors. In our studies, an imidazole inhibitor of aromatase which acts competitively (i.e. CGS 16949A) is 1000-fold more potent than aminoglutethimide and ten-fold more potent than 4-hydroxyandrostenedione in vitro. In sixteen postmenopausal women, doses 500-fold less than standard doses of aminoglutethimide inhibited plasma and urinary oestrogens measured by radioimmunoassay or GLC mass spectrometry to the same extent as with aminoglutethimide. The use of sulphatase inhibitors, another means of oestrogen deprivation, may potentially be feasible. Sulphatase inhibitors are active in vitro but currently lack potency and specificity for the sulphatase in breast cancer tissue itself.

In premenopausal women, the oestrogens are directly aromatised from androgens in ovarian tissues through the stimulatory influence of LH and FSH. Suppression of these gonatrophins with or without additional aromatase inhibitors provides a means of inhibiting oestrogen in premenopausal women. Aromatase inhibition, alone, will probably not be effective because of the reflex rise in LH and FSH observed. Our studies indicate effective suppression of oestradiol in premenopausal women with the GnRH superagonist analogue, Leuprolide. However, combined use of this superagonist analogue plus an aromatase inhibitor would have the advantage of blocking synthesis of oestrogen, both in ovary and in extraglandular sites.

The present paper is the first step in an attempt to combine study of the genetics of coat colour in dogs with histological examination of the hairs and pigmentation, so that a picture may eventually be formed of the genetic relations of the various phenotypes, and of the processes by which the various colours are produced. Work along similar lines has been carried out by other workers on various mammals, e.g. on the mouse (Dry, 1926, 1928; Dunn, 1936; Einsele, 1937), guinea-pig (Wright and Hunt, 1918; Russel, 1939; Heidenthal, 1940), and in cattle (Bogart and Ibsen, 1938).

The technical and scientific problems of ecological monitoring at Port Valdez, Alaska are discussed. Particular attention is given to the problems created by lack of understanding of the processes of the Alaskan Rocky Shore ecosystem and the paucity of data on the natural stresses controlling temporal and spatial variation in populations. In addition, taxonomic difficulties, particularly in the littoral macroalgae, further compound survey problems.

The paper suggests some possible approaches that could be applied and is illustrated by data taken on baseline surveys made in 1977. Particular attention is given to unexpected age size distributions in the limpet Collisella pelta.

Ichthyogeography is the section of biogeography which seeks to interpret fish biodiversity in terms of present and past distributions and abundance. It can also have practical applications in fisheries management and conservation. There are thought to be more than one thousand species of fish in the 40 or so major rivers of the Guinea–Congo rain forest region, with correspondingly high levels of endemicity. In the Congo or Zaire river basin alone, the proportion of endemic fish species may exceed 80% (from a total of >690), but many more taxonomic and distributional data remain to be gathered.

Unlike terrestrial vertebrates, the diverse freshwater fishes of Guinea–Congo evidently have distributions which are closely confined by hydrography. Hence, fish distributions may be of particular help in corroborating or refuting postulated geological events, patterns and processes and in explaining associated aspects of rainforest evolution. From the 19th century until now, the ichthyogeography of Guinea–Congo has been diagnosed largely in terms of presumed post-Miocene geological sequences of fish taxa and their past and recent dispersal in relation to particular hydrological conditions: mainly riverine volume discharge, salinity and temperature. From this, the fish fauna is, by convention, divided into ‘provinces’ established on endemism, palaeogeography and supposed physical or ecological barriers to dispersal. However, in this paper it is argued that the traditional ichthyogeographical accounts which highlight endemism and dispersal are generally flawed. It is argued here that historical patterns of fish distribution can only be fully understood if phyletic (cladistic) data are taken into consideration. While Upper and Lower Guinea and the Zaïre basin may be defined in part on the basis of endemism there is a lack of taxonomic and distributional evidence to show that Guinea–Congo is itself a cohesive ichthyogeographical unit.

There is clearly a need for comparisons with fish distributions outside the rain forest zone of Guinea–Congo. African inter-provincial, trans-continental and inter-continental comparisons reveal distribution patterns which may relate more to pre-Miocene rather than post-Miocene geology or present-day rain forest ecology. Continental drift, notably between Africa and South America, probably led to the separation 85 million years ago of previously united fish populations. This may account for recent higher-level phyletic correspondences between the separate rain forest fish faunas of Africa and the neotropics.

Last, the so-called ‘marine intrusive’ fishes – which are normally excluded from zoogeographical consideration – merit a careful re-evaluation. While they may be regarded as an inconvenience in developing scientific hypotheses, such intrusives can comprise a remarkable 30% or more of the riverine fish fauna in Guinea–Congo. It seems that the widely accepted ecological divisions between marine and ‘primary freshwater’ fishes are not as clear-cut as has been supposed. In addition, zoogeographically critical marine, trans-Atlantic, phyletic relationships apparently exist. These are probably best interpreted by using area cladograms in the context of ocean basin development, rather than by referring solely to marine fish dispersal and the traditional continental and provincial ichthyogeography of Guinea–Congo.

A cytological study of the testes of the cat was undertaken in order to disclose the structural differentiation of the sex chromosomes. It was hoped that an analysis of these particular chromosomes in the male sex during meiotic division might reveal structural peculiarities which would throw some light upon the highly complex genetical behaviour of tortoise-shell cats.

Marked interspecific differences in recent population trends have been recorded for seabirds breeding in the Firth of Clyde. Auk populations have remained comparatively stable, while considerable reductions have taken place in tern and kittiwake numbers. Shags, cormorants, gannets and great black-backed gulls have all increased, as have fulmars and herring gulls. The striking increases in the latter two species are considered in detail. To some extent, these population changes can be related to differences in the feeding ecology of the various seabirds; in particular the variation in the number of breeding terns is related to variation in food availability.

The Clyde Estuary is recovering from gross pollution. In the early 1970s high densities of a small number of species of intertidal invertebrates tolerant of organic enrichment and low oxygen levels provided rich feeding for large numbers of dunlin, redshank, lapwing, oystercatcher and curlew. Winter numbers of the first three species have now declined considerably. The declines cannot be attributed to national changes in wader numbers and are not due to changes in breeding habitats or lack of reproductive success in particular regions, since each species wintering on the Clyde Estuary breeds in a different area. The most likely explanation of the decline, which is most pronounced in the species highly dependent on Corophium volutator, is either that reduced organic pollution has reduced the densities of the main prey, or that higher oxygen levels over the mudflats have allowed fish, particularly flounders, to enter the estuary and compete with the waders for the available prey. Although there is evidence of some birds having moved to other wintering areas, the fate of most birds is unknown.

Mass blooms of purple sulphur bacteria belonging to the genera Thiocapsa and Chromatium (> 108 viable cells/g dry wt sediment) develop in localised areas at the sand/air interface on a number of sheltered beaches in Scapa Flow each summer. These anaerobic bacteria grow phototrophically using H2S as e− donor and develop in association with other groups of phototrophic and heterotrophic bacteria. Oxygen consumption by the heterotrophs is greater than O2 production by the algae and diffusion from the surface and this rapidly leads to anaerobic conditions in the sub-surface sediments (0–10 mm depth). Under these conditions, significant populations of sulphate reducing bacteria develop (circa 105 viable cells/g dry wt sediment) and reduce SO2−/4 to S2− during the anaerobic oxidation of low molecular weight organic substrates. Sulphide generated in this process is used as the e− donor in photosynthesis by the purple sulphur bacteria and in turn is re-oxidised to SO2−/4. Sulphate reduction is dependent upon the availability of oxidisable low molecular organic substrates which are produced, as metabolic end-products, during the microbial decomposition of algal detritus. Blooms of Thiocapsa and Chromatium spp. were most pronounced on beaches such as Scapa, Waulkmill and Swanbister, which in localised areas, have high total organic carbon contents (5–12% w/w). The factors regulating the development of these localised mass developments of anaerobic phototrophic bacteria in apparently aerobic environments are discussed.

The mechanism by which irradiation produces gross re-arrangements of chromosomes (inversions, translocations, deletions) is now generally believed to occur in two steps: (a) breakage of one or more chromosomes, yielding two or more points of breakage; and (b) reunion of broken ends in a novel combination. Thus the frequency with which a given treatment produces re-arrangements depends not only on the number of breaks produced, but on the circumstances under which reunion takes place. In Drosophila the fertilized ovum seems to offer particularly favourable conditions for breaks produced in the mature spermatozoon to join up into new combinations. In immature germ-cells, on the other hand, re-arrangements are much less readily produced by irradiation (Muller, 1930; Shapiro and Neuhaus, 1933; Shapiro, 1937; Glass, 1939). Evidence for the occurrence of spontaneous or induced re-arrangements in somatic cells of Drosophila is very scanty.

The Phragmites communis marshes occupy 250–330 hectares bordering the northern tidal flats of the Tay Estuary. The outer edge of the marsh forms a step up to 50 cm in height. Reed stems grow with densities of 90–150/m2 and break to produce upward facing cylinders which entrap sediments. Measured daily accretion rates in broken stems varied from 001 g to 0.07 g. Sedimentation was greatest during spring tides, but decreased with falling tidal range. Accretion of 16 g per stem is normal and many stem plugs have greater weight. Annual rates of contribution from instem accumulation vary between 0.9 and 2.6 kg/m2 on the marsh margin. Stem fall provides cylindrical sedimentary lumps to the marsh sediments, whose internal structure reveals nodules and thin laminae juxtaposed.

Nuclepore membranes of known pore size and porosity, attached to small glass chambers were used to investigate the mechanism of humidity-induced convection found in Phragmites and other species. The convective flow of gases and the development of static pressures were studied in relation to a variety of conditions imposed on opposite sides of the membrane. Data were obtained in relation to pore size (0.015 to 3 μm diameter) and porosity, temperature and humidity gradients, membrane area and resistance to venting.

A humidity gradient across the Nuclepore membranes was far more effective than a temperature gradient per se for inducing flow; also pores of the order 0.2 μm diameter were the most effective. With a steep enough humidity gradient, however, significant flows could also be induced across pores as large as 2 μm diameter. The results accord with previous experiments and observations on Phragmites and with the mathematical treatment of the mechanism. It is concluded that humidity-induced convection should play a greater role than thermal transpiration (thermo-osmosis) in effecting convections in Phragmites and other non-floating-leaved species.

Relatively little research has been done on mycorrhizas of Sitka spruce, although greenhouse studies have confirmed that its growth can be improved by the introduction of mycorrhizal fungi. Work in nurseries is difficult under British conditions and it probably will be necessary to disinfest soil in seedbeds before mycorrhizal treatment can be applied. Results from forest trials show that inoculation with selected mycorrhizal fungi can give significant early growth effects, though how long these will persist is unknown. In such work, careful attention must be given to selection of controls. Features covered in this review include a discussion of fungi mycorrhizal with Sitka spruce, identification of mycorrhizas, nutrient uptake, and growth enhancement of seedlings and transplants.

Interactions amongst plants and different endophytes are prevalent in soils deficient in both nitrogen and phosphorus. Several systems are now recognised, combining infections by both fungi and prokaryotes. Symbiotic associations are ancient and reflect the requirements for the maximum uptake of nitrogen and phosphorus in plant nutrition.

The ciliary feeding mechanism of Amphioxus (Branchiostoma bermudœ) is dependent for its continued effectiveness on the cleaning action of a powerful current of water produced by movements of the floor of the atrium. As ciliary feeding progresses, the buccal cirri become heavily choked with particles of detritus, and the feeding current entering the pharynx is thereby reduced. When this occurs, the atrial floor is violently raised and lowered, and water is pumped in and out of the atrium by way of the pharynx and oral hood, dislodging the accumulated particles from the buccal cirri. As is to be expected, the atriopore is capable of being closed during this process.

An extensive reed bed on the north shore of the inner Tay Estuary is briefly described. Studies in the summers of 1975, 1976 and 1978 showed it to comprise monodominant stands of Phragmites communis Trin. The standing crop of shoots was sampled at the end of the season of vegetative growth and analysed by simple biometrical methods. Certain important spatial and architectural characteristics of the community varied in a regular manner with position in the bed. Estimates of the above ground productivity of intact stands ranged from 100 to 150 tonnes/ha in a poor growing season. Commercial harvesting operations, conducted since 1975, produced an immediate and consistent decrease in shoot stature, apparently followed by a slow increase in density and productivity. The behaviour of the downshore edge of the bed and the details of its annual development above and below ground require further study.

The apparatus described was developed in connection with a study of the growth and development of the stick insect, Dixippus morosus. The principle is that of simple displacement, and consistent results are obtained with objects as small as 0·007 millilitre.

A 3-year survey of wild fish in Loch Awe and the surrounding watershed has shown a restricted distribution and low prevalence of infection with infectious pancreatic necrosis virus. No signs of clinical disease were observed in infected fish. The restricted distribution close to a rainbow trout farm is consistent with the virus originating from this farm, where virus infected stocks have been found each year since 1971. The continuing low prevalence is also consistent with virus in wild fish resulting from the spread of infection from the farm. If infection is spreading between wild fish, it is slow within the time scale of the survey. The possible mechanisms of transmission of infection from the farm to wild fish are discussed.

Life histories and production of the five common species of Tanypodinae (Pentaneura monilis, Procladius simplicistilus, P. crassinervis, P. choreus and Psilotanypus rufovittatus) in the mud at Loch Leven were measured from March 1971 to March 1972. The methods used to identify each species of larva are described. All were univoltine except Pentaneura monilis which had two generations per year, but the seasonal patterns of the life cycles were different. The average density of third and fourth instar Tanypodinae was 3100/m2 and densities of individual species exceeded 2500/m2 for short periods in Procladius crassinervis and P. choreus. Net annual dry weight production by this subfamily was 2·6 g/m2(57 kJ/m2), with individual species ranging from 1·1 g/m2 (P. crassinervis) to 0·16 g/m2 (Pentaneura monilis). These results are discussed briefly and compared with production estimates for other zoobenthos.