Showing papers by "University of Stirling published in 1978"
01 Jan 1978
243 citations
TL;DR: In this article, the authors investigated the relationship between group algebra and semigroup amenability for inverse semigroups S and obtained partial results for S with infinite sets of idempotent elements.
Abstract: If G is a group, then G is amenable as a semigroup if and only if l1(G), the group algebra, is amenable as an algebra. In this note, we investigate the relationship between these two notions of amenability for inverse semigroups S. A complete answer can be given in the case where the set Es of idempotent elements of S is finite. Some partial results are obtained for inverse semigroups S with infinite Es.
137 citations
01 Jan 1978
88 citations
TL;DR: Evidence is presented which suggests that the incidence of infection in mature male salmonid fish prior to spawning is significantly greater than in the females, and this difference may not be apparent in spent fish after spawning.
Abstract: . Fungal infection of sexually mature brown trout and char was associated with a particular type of Saprolegnia exhibiting a low degree of homothallic sexuality. Hatchery-reared brown trout were more severely infected (in terms of the % area of the body covered with the fungus) than were wild fish. The fins of hatchery-reared fish were particularly prone to Saprolegnia infection regardless of sex. In wild brown trout, a sexual difference in the pattern of infection was demonstrated. The flanks of the male fish appeared to be more prone to infection when compared with the female and there was a greater susceptibility of the caudal and ventral fin of the female when compared with the male. Evidence is presented which suggests that the incidence of infection in mature male salmonid fish prior to spawning is significantly greater than in the females. This difference may not be apparent in spent fish after spawning. These findings are discussed in relation to the background concentration of fungal spores in the water, the behavioural characteristics of spawning fish and differences in epidermal structure.
86 citations
TL;DR: Ultrasonic telemetry was used to follow the movements of two groups of smolts in the estuaries of two small Scottish rivers, finding that wild Smolts released into a typical wedge flow, partially mixed estuary had movements which were dominated by the influence of tide on the direction of water flow.
Abstract: Ultrasonic telemetry was used to follow the movements of two groups of smolts in the estuaries of two small Scottish rivers. Hatchery reared smolts released into a typical wedge flow, partially mixed estuary had movements which were dominated by the influence of tide on the direction of water flow. The net movements of wild native smolts in a two layer flow estuary, in which freshwater flow dominated, was downstream but were intermittent consisting of short steps and numerous long pauses. The hatchery reared smolts escaped from the estuary within a tidal cycle, moving out on an ebb tide. The wild smolts remained in the estuary for periods up to 108 h, none escaping within one tidal cycle.
81 citations
TL;DR: The results of laboratory experiments on ciliate reproductive and respiratory rates have been combined with field data for ciliate numbers, to produce estimates of production and respiratory energy losses by communities of benthic ciliates.
Abstract: SUMMARY. The results of laboratory experiments on ciliate reproductive and respiratory rates have been combined with field data for ciliate numbers, to produce estimates of production and respiratory energy losses by communities of benthic ciliates. Annual production decreased with increasing depth, and it was estimated to be 345, 149 and 40 J cm−2 year−1 at three sites in Airthrey Loch, Scotland. A similar trend with increasing depth was recorded for annual respiratory energy losses, being 16, 11 and 4 J cm−2 year−1 at the three sites. The corresponding annual net production efficiencies (%) were 95.2, 93.1 and 91.5. When net production efficiencies were calculated for each period (the time between successive sampling occasions) as 100 (daily production/daily assimilation), the range extended from 63 to 98. The energetic efficiencies of the ciliate populations are discussed with reference to data in the literature for higher organisms.
65 citations
TL;DR: In this article, the rates of secondary production by the individual macrofaunal invertebrates of two Indian beaches are presented and these are combined to give an estimate of the energy flow through the macrobenthos of the two beaches.
Abstract: Estimates of the rates of secondary production by the individual macrofaunal invertebrates of two Indian beaches are presented and these are combined to give an estimate of the energy flow through the macrobenthos of the two beaches. The production by individual species and by the macrofauna as a whole is compared with that of other tropical, and of temperate beaches, and it is concluded that a similar biomass in the tropical beaches produces a rate of turnover of biomass some ten times that of the temperate beaches. Values of production to biomass ratios (P/B) and of elimination to biomass ratios (E/B) for the invertebrates of sandy substrata in various geographical areas are reviewed and the use of these ratios in comparisons of productivity, and their relationship to mortality and longevity are discussed.
63 citations
TL;DR: In this article, the authors reported that children copied simple line drawings of perspective views of cubes and similar designs unlikely to be seen as representing objects, and the errors made in copying the cubes involved replacement of properties specific to the single perspective view by properties more appropriate to the object itself.
63 citations
TL;DR: Histological effects consisted principally of granuloma formation, especially in the posterior kidney and spread appeared to occur both by extension and by the liaematogenous route, suggesting that the original infection occurred via contaminated food.
Abstract: . Infection of Atlantic salmon, Salmo salar L., in seawater with Exophiala salmonis is described. Histological effects consisted principally of granuloma formation, especially in the posterior kidney and spread appeared to occur both by extension and by the liaematogenous route. The nature of the outbreak suggested that the original infection occurred via contaminated food.
A comparison is made between this condition and systemic mycoses in other species.
56 citations
TL;DR: The secretory cells of the digestive glands of up to 75% of Tellina tenuis from sheltered sandy beaches on the Scottish coast contained intracytoplasmic inclusion bodies consisting of microcolonies of a rickettsia-like organism that closely resemble those of the genus Coxiella of the family Rickettsiaceae.
Abstract: . The secretory cells of the digestive glands of up to 75% of Tellina tenuis from sheltered sandy beaches on the Scottish coast contained intracytoplasmic inclusion bodies consisting of microcolonies of a rickettsia-like organism. The development and morphology of these parasitic bacteria and the cytopathic effect on the host cells are described. These features closely resemble those of the genus Coxiella of the family Rickettsiaceae. It was possible to culture the organism in embryonated hens' eggs. Scattered particles and paracrystalline arrays of a virus were seen in association with the bacteria. This is believed to be the first description of a phage from a rickettsia.
54 citations
TL;DR: There was a very rapid migration of Malpighian cells into the defect which was not accompanied by any evidence, over the time-scale of the study, of a mitotic burst, and adjacent normal skin was markedly reduced in thickness.
Abstract: An autoradiographic study of experimental wounding of the skin of juvenile plaice was performed using tritiated thymidine (20 μCi per gram body weight) injected intraperitoneally, at water temperatures of 5, 10 and 15°C.
Samples of lesion were taken at regular intervals up to 108 hours and autoradiographic preparations made. In addition wounds of less than 12 hours duration, unsuitable for autoradiography were examined and in vitro explant autoradiography studies on similar material used to support the findings for these short term lesions. Results showed that there was a very rapid migration of Malpighian cells into the defect which was not accompanied by any evidence, over the time-scale of the study, of a mitotic burst. Adjacent normal skin was markedly reduced in thickness. Closure of these relatively small wounds was achieved within nine hours at 10°C and by 12 hours at 5°C. The thickness of the migrated epidermal cover was much thicker at 15°C than 5°C.
Numbers of labelled cells were similar in migrating and peripheral epidermis and mucous cells appeared to be randomly distributed except in the periphery of advancing migrating cells, where thev were absent.
TL;DR: Straight-chain saturated fatty acids (C6-C11) and abscisic acid (ABA) accumulate in the leaves of Phaseolus vulgaris L. and Hordeum vulgare L. under water stress and certain of the fatty acids, particularly decanoic and undecanoic acid, can inhibitStomatal opening and cause stomatal closure in epidermal strips of Commelina communis L .
Abstract: Straight-chain saturated fatty acids (C6-C11) and abscisic acid (ABA) accumulate in the leaves of Phaseolus vulgaris L. and Hordeum vulgare L. under water stress. ABA and certain of the fatty acids, particularly decanoic and undecanoic acid, can inhibit stomatal opening and cause stomatal closure in epidermal strips of Commelina communis L. depending on the incubating medium used. 10-4 M (±)-ABA inhibits opening in media containing either high or relatively low concentrations of KCl but causes closure only in the latter medium. The fatty acids (at 10-4 M) prevent opening in both media while significant closure of open stomata was caused only by undecanoic acid in both media and, additionally, by decanoic acid in the low-KCl medium. 10-4 M formic acid also caused stomatal closure and prevented opening to significant extents in the low-KCl medium (it was not tested in the high-KCl medium). The efficacy of undecanoic acid in causing 50% inhibition of opening is about three orders of magnitude lower than that of ABA. At a concentration of 10-3 M, nonanoic, decanoic and particularly undecanoic acid and all-trans-farnesol cause increased cell leakage in Beta vulgaris L. root tissue. Undecanoic acid (10-4 M) also causes some loss of guard cell integrity in C. communis within 1.5 h of treatment. ABA (10-4 M) reduces transpiration rates in barley and C. communis leaves when applied via the transpiration stream but decanoic and undecanoic acids did not have this effect. Transpiration was not affected when ABA or the fatty acids were applied to the leaf surfaces.
TL;DR: Results indicate the presence of three daily peaks of feeding activity, which is discussed in relation to changes in light levels, and telemetry records indicate that night feeding is a common occurrence in brown trout.
Abstract: A technique is described whereby the electromyogram of the m. adductor mandibulae of brown trout is detected by implanted extracellular electrodes and used as the input signal for an ultrasonic transmitter attached externally to the fish. The periodic electrical activity of the muscle during ventilation is relayed by the transmitter using an analogue pulse system.
As the ventilatory electromyogram occurs in discrete rhythmic trains, it follows that alterations to this rhythm can be used to telemeter, instantaneously, single feeding events from a free swimming fish. Laboratory tests have shown that the feeding act is unequivocally distinct electromyographically from other manoeuvres such as ‘coughing’.
Four adult brown trout have been equipped with this transmitter system and released in Airthrey Loch, Stirling. Using a tracking facility, feeding activity and ventilatory rhythms have been recorded for extended periods.
The results indicate the presence of three daily peaks of feeding activity, which is discussed in relation to changes in light levels. The telemetry records indicate that night feeding is a common occurrence in brown trout. In addition, ventilatory rates were found to be at or near resting levels.
Journal Article•
TL;DR: The neuroleptanalgesic combination of etorphine HCI/acetylpromazine maleate (Immobilon) gave, qualitatively, the best anaesthesia of all the drugs tested and was immediately reversible by injecting the antagonist diprenorphines HCl (Revivon).
TL;DR: The standard enthalpy of formation of triphenylbismuth has been measured by oxygen aneroid rotating-bomb calorimetry using hydrochloric acid as solvent for the solid combustion products to form a well-defined final solution as discussed by the authors.
TL;DR: Red Mexican developed a confluent hypersensitive reaction at sites inoculated with suspensions containing 10 8 cells ml −1 of Pseudomonas phaseolicola race 1 and cellular degeneration involving similar changes in ultrastructure appeared to be induced in cells adjacent to those responding directly to attached bacteria.
Abstract: Unifoliate leaves of Phaseolus vulgaris cv. Red Mexican developed a confluent hypersensitive reaction (HR) at sites inoculated with suspensions containing 10 8 cells ml −1 of Pseudomonas phaseolicola race 1. The time for induction of the HR was 4 h; symptoms first appeared 18 h after inoculation. The collapse of mesophyll cells did not occur synchronously during development of the HR. Under the light microscope degenerate cells were first observed 18 h after inoculation and their numbers increased until by 48 h all spongy and palisade mesophyll cells had collapsed. Four hours after inoculation most bacteria appeared to be attached to bean cell walls which were partially eroded at the site of attachment. Aggregation of host cytoplasm adjacent to bacteria led to localized cytoplasmic invasion of the vacuole, accumulation of osmiophilic droplets throughout the cytoplasm, vesiculation, degeneration of organelles and finally collapse of responding cells. Cellular degeneration involving similar changes in ultrastructure also appeared to be induced in cells adjacent to those responding directly to attached bacteria. These observations are discussed with reference to recent hypotheses on the control of the hypersensitive response.
TL;DR: The addition of up to 8.5 % sodium chloride to the diet of rainbow trout Salmo gairdneri had no significant effect on either food intake or food conversion efficiency.
Abstract: The addition of up to 8.5 % sodium chloride to the diet of rainbow trout Salmo gairdneri had no significant effect on either food intake or food conversion efficiency. Over a range of rations from 4 % to 38 % of dry weight per week, there was a rectilinear relationship between ration and growth rate. The weight maintenance requirement and rate of weight loss during fasting were estimated from this relationship. Food conversion efficiency (K) increased from 0.00 at 4% dry weight per week food intake (x) to 0.19 at 38%, according to the equation K=0.21-0.77/x.
TL;DR: When cuttings of Calluna from each population were grown in all soil types, it was shown that these samples were adapted to the different soils.
Abstract: SUMMARY
Samples of Calluna vulgaris were collected from several sites of contrasting soil type and the mineral status of plants and soils measured. Differences in the concentrations of several potentially toxic elements in these plants and soils occurred but the nitrogen, potassium and phosphorus concentrations, particularly in the plants, were similar. When cuttings of Calluna from each population were grown in all soil types, it was shown that these samples were adapted to the different soils. Two ways in which this species may be adapted to tolerate high concentrations of lead were noted.
TL;DR: In this paper, eight anaesthetic drugs were tested by intramuscular or intraperitoneal injection in trout and the neuroleptanalgesic combination of etorphine HCI/acetylpromazine maleate (Immobilon) gave, qualitatively, the best anaesthesia of all the drugs tested and was immediately reversible by injecting the antagonist diprenorphineHCl (Revivon).
TL;DR: In this article, the standard enthalpies of combustion for five C 7 bridged-ring hydrocarbons have been measured in a static combustion bomb calorimeter, based on the dependence of vapour pressures on temperature.
TL;DR: In this article, the authors present evidence that ABA can accumulate in the stomatal complex of Commelina communis L. The evidence is based on experiments involving the uptake, distribution and metabolism of exogenous 2-14C-ABA.
Abstract: THE plant hormone abscisic acid (ABA) is thought to be involved in the regulation of transpiration through its effects on stomatal aperture1. Application of synthetic ABA causes stomatal closure in whole plants2, shoots3 and leaf epidermal strips4. During water stress, levels of the hormone increase in plant tissues5, including the leaf epidermis6, and this is usually associated with stomatal closure7. There is evidence that ABA affects the ionic8,9 and metabolic9 status of the stomatal complex and it has been concluded that ABA acts directly on guard cells in effecting stomatal closure8,10,11. There is, however, little information about the distribution of ABA in specific cells of the epidermis or about the sensitivity of the stomatal complex to ABA. We present here evidence that ABA can accumulate in the stomatal complex of Commelina communis L., a species used extensively in studies of stomatal physiology12. The leaves of this plant yield relatively uncontaminated epidermal strips13 and this property has made it possible to calculate the apparent sensitivity of the stomatal complex to ABA. The evidence is based on experiments involving the uptake, distribution and metabolism of exogenous 2-14C-ABA.
TL;DR: The Pre-Capitalist Modes of Production as mentioned in this paper, a comparative study of the domestic domain of production and reproduction, was published by Goody et al. London: Routledge and Kegan Paul, first published 1975; paperback edition 1977. Pp. vi+3S4.
Abstract: Pre-Capitalist Modes of Production. By BARRY HINDESS and PAUL Q. HIRST. London: Routledge and Kegan Paul, first published 1975; paperback edition 1977. Pp. vi+3S4. £7.50, pbk £3.75. Relations of Production: Marxist approaches to economic anthropology. Edited by DAVID SEDDON. London: Frank Cass, 1978. Pp. xiii+414. £12.50, pbk £5.50. Production and Reproduction: a comparative study of the domestic domain. By JACK GOODY. Cambridge University Press, 1976. Pp. xiii+157. £6.00, pbk £2.20.
TL;DR: The work reviewed in this article will however refer to the enzyme isolated from rabbit skeletal muscle, as it is this form which has been the most intensively studied.
TL;DR: There was a marked decrease in intestinal and rectal cross-sectional area and height of intestinal villi with starvation except in 32.5 p.p.t. sea water, and a 48 day period of starvation had little effect on the posterior oesophagus and the cardiac stomach.
Abstract: A study has been made of the effects of salinity, starvation and salinity-starvation interactions on the structure of the alimentary canal of immature rainbow trout Salmo gairdneri Richardson. Intestinal and rectal cross-sectional areas and the height of the intestinal villi increased with salinity. The thickness of none of the tissue layers measured in the intestine and rectum, including the columnar epithelium and the tunica propria, was influenced by salinity. There was a significant negative correlation between salinity and mucous cell distribution density in both the intestine and rectum. In trout acclimatised to salinities of 15.0 p.p.t. (parts per thousand) and above, there was a high incidence of deep depressions in the columnar epithelium. The oesophagus and stomach were not visibly affected by salinity.
There was a marked decrease in intestinal and rectal cross-sectional area and height of intestinal villi with starvation except in 32.5 p.p.t. sea water. Mean intestine epithelial cell height decreased with starvation at 32.5 p.p.t. A 48 day period of starvation had little effect on the posterior oesophagus and the cardiac stomach.
TL;DR: In this article, the effects of ambient humidity on relative water contents (RWC) and water potentials were measured separately for epidermal and mesophyll tissues in leaves of two species.
Abstract: Effects of ambient humidity on relative water contents (RWC) and water potentials were measured separately for epidermal and mesophyll tissues in leaves of two species. Water potentials did not always change in the same direction as RWC within the same tissue and rarely were the changes in water potential and RWC of one tissue correlated with those of the other. The nature of the humidity responses of stomata in certain species is discussed in relation to these results and to the anatomical properties of epidermal tissues.
TL;DR: The structure of the male reproductive system of the marine calanoid copepod Euchaeta norvegica Boeck is described and its histology and ultrastructure are examined in detail, indicating that a male's potential output of spermatophores during its lifetime is three or more.
TL;DR: The morphology of the herpes‐type viral infection of the epithelia of the skin and gills is described with ultrastructural observations on its morphogenesis and release from infected cells.
Abstract: . Recent heavy mortalities amongst O+ group turbot at a fish farm were found to be associated with a herpes-type viral infection of the epithelia of the skin and gills. The morphology of the virus is described with ultrastructural observations on its morphogenesis and release from infected cells.