Showing papers by "James Cook University published in 1977"
TL;DR: Size classes can be discerned in field size frequency data for Acanthaster planci which may be interpreted as age classes, which enables a possible field growth curve to be derived, which is consistent with measured growth data from the laboratory and from field experiments.
77 citations
TL;DR: The role pneumatophores play in affecting sedimentation patterns is investigated by a series of rods set up as grids of different sizes placed in front of the mangroves on Magnetic Island, north Queensland as mentioned in this paper.
75 citations
TL;DR: The distribution and ecological niche of the dugong are considered in relation to their effects on tropical seagrass ecosystems, features of the chemical and calorific nature ofSeagrasses are contrasted to those of most terrestrial plants.
58 citations
TL;DR: Although the volatile fatty acid concentrations in the caecum and large intestine were considered unnaturally high, it is obvious that the contribution of the hindgut to the digestion of the dugong is considerable.
56 citations
TL;DR: In this article, the authors proposed energy storage in the form of heat of adsorption in beds of adsorbent material, which is most readily achieved by nominating water as the adsorbate so that water vapour is transferred to or from the absorbent from the humid air flowing through the bed.
54 citations
TL;DR: Bubbles formed on coral tissues and on several macroalgae under conditions of high illumination contained large amounts of oxygen, suggesting that a high oxygen tension may occur in coral tissues during the day.
Abstract: Compensation point and light-saturation values were determined from oxygen-exchange experiments with branches and isolated zooxanthellae from the staghorn coral Acropora acuminata. Branches and dense suspensions of zooxanthellae showed similar lightresponse curves for oxygen exchange, with light saturation at about 23 Klux (300 W. m-2) and compensation point occurring between 4 and 6 Klux (60–80 W. m-2). Zooxanthellae appear to be mutually shaded in dense suspensions and coral tissues. The effects of metabolic inhibitors, including photosynthetic and respiratory inhibitiors, on oxygen exchange in coral branches and isolated zooxanthellae are presented. Bubbles formed on coral tissues and on several macroalgae under conditions of high illumination contained large amounts of oxygen, suggesting that a high oxygen tension may occur in coral tissues during the day. Photorespiration and dissolved organic carbon production by suspensions of zooxanthellae are discussed in relation to a high oxygen tension which probably occurs in coral tissues during daylight.
54 citations
TL;DR: Urate oxidase, allantoinase and allantoicase activities were present in liver extracts of P. gracilis and P. expeditionium, and liver extracts showed arginase and ornithine carbamoyltransferase activities but other enzymes of the Ornithine-urea cycle were not detected.
45 citations
TL;DR: In this paper, six highly crosslinked polystyrene-supported phosphines have been prepared by suspension copolymerization, and used to convert alcohols in high yield to chloroalkanes, in carbon tetrachloride as co-reagent and solvent.
42 citations
TL;DR: A new method employing a formal probability frequency function which relates the number of shared taxa to sample size and inferred population size for a pair of areas, which assumes random selection of taxonomic samples by the fossil record from larger complete populations originally occurring in the areas concerned.
Abstract: Existing methods of quantitative paleobiogeographic analysis, based on the statistical use of binary similarity coefficients, are shown to be defective. A new method employing a formal probability frequency function which relates the number of shared taxa to sample size and inferred population size for a pair of areas, is introduced. It assumes random selection of taxonomic samples by the fossil record from larger complete populations originally occurring in the areas concerned. Quantitative assessment of population diversity as well as population similarity expressed as percentage overlap with attendant error estimates result from the method, but the final phase of analysis remains, of necessity, both manual and inexact. Utility of the method is demonstrated by working simulated data and actual data pertaining to late Cretaceous ammonites.
40 citations
TL;DR: Porcine foetuses of dams experimentally infected with porcine parvovirus showed differing histopathological and immunofluorescent characteristics dependent on gestational age, whilst less obvious histopathic changes with significant antigen fluorescence were present in foetus which had not reached immunocompetence.
29 citations
TL;DR: The safety and immunogenicity of inactivated porcine parvovirus (PPV) vaccines were investigated and beta-propiolactone and formalin successfully inactivated virus without destroying Immunogenicity, which was considerably enhanced by incorporation of a gel adjuvant in the vaccine.
Abstract: The safety and immunogenicity of inactivated porcine parvovirus (PPV) vaccines were investigated. Both beta-propiolactone and formalin successfully inactivated virus without destroying immunogenicity, which was considerably enhanced by incorporation of a gel adjuvant in the vaccine. Using the formalised-gel vaccine, initial antibody responses were demonstrated in susceptible piglets and adult pigs at 7 days after vaccination. These antibody responses persist at significant levels for at least 6 months after vaccination. Antibody levels increased up to 16 fold when revaccination was carried out. Vaccination of gilts with low level (passive) immunity resulted in antibody responses comparable to those recorded in susceptible pigs. The vaccine was safe as determined by absence of residual virus in the vaccine, absence of viraemia and excretion in vaccinted stock, and absence of effect on litters of sows vaccinated at different gestational ages. Vaccine stored at 4 degrees C for 6 months was as immunogenic as fresh vaccine.
TL;DR: The Townsville fauna is to some extent similar in species composition to that of the north Queensland rain forests, although some species abundant in Townsville are considerably rarer in the undisturbed natural forests and, conversely, a few of the most common forest species were not detected in the city.
Abstract: In an investigation of the urban drosophilid fauna of Townsville, Queensland, 18 species were collected, 16 of them at household refuse heaps effectively acting as baits. Four of the baited species (Drosophila bipectinata Duda, D. kikkawai Burla,.1). sp. ef. jambulina Parshad and Paika, Sphaerogastrella javana (de Meijere)) are new records for Australia. The Townsville fauna is to some extent similar in species composition to that of the north Queensland rain forests, although some species abundant in Townsville are considerably rarer in the undisturbed natural forests and, conversely, a few of the most common forest species were not detected in the city. The Townsville urban drosophilid fauna differs substantially from that of southern Australia.
TL;DR: The tropical intertidal limpet Acmaea antillarum (Sowerby) was used in a series of field and aquarium growth studies, carried out in Venezuela and it was shown in aquarium experiments that the normal growth pattern was inhibited in constant darkness and that continous illumination stimulated the formation of extra growth ridges.
Abstract: The tropical intertidal limpet Acmaea antillarum (Sowerby) was used in a series of field and aquarium growth studies, carried out in Venezuela. Both field and aquarium experiments demonstrated the formation of diurnal growth ridges and subdiurnal periodic growth striations on the shell surface. It was shown in aquarium experiments that the normal growth pattern was inhibited in constant darkness and that continous illumination stimulated the formation of extra growth ridges. Alterations of the experimental sequence of illumination influenced the formation of subdiurnal growth markings. This secondary growth pattern appears to be distinct from the basic system of diurnal ridge formation. Limpet shell lengths were related to estimated age based on diurnal growth ridge counts. It is probable that maximum shell size is attained in less than 1 year. Equations for allometric shell growth characteristics were calculated relative to shell length. Calculations for instantaneous relative growth rate were made from natural populations, experimental field populations and aquarium specimens. These were compared to show that the field and aquarium experiments demonstrated similar growth rates. The results of these observations and calculations are compared with other molluscan growth studies.
TL;DR: In this article, the problem of selecting a state feedback controller with a specified structure so as to minimize the expected value of quadratic cost for a discrete linear system disturbed by a zero-mean white noise disturbance is posed.
Abstract: The problem of selecting a state feedback controller with a specified structure so as to minimize the expected value of quadratic cost for a discrete linear system disturbed by a zero-mean white noise disturbance is posed. The cost is expressed as a quadratic form in the gains associated with a given time. It is then suggested that an optimal control policy of specified structure might be computed by repeatedly replacing the gains associated with each time instant with an optimal choice given that the gains associated with all other time instants are held fixed. The properties of the solution and of the solution procedure are discussed. An example is given illustrating that simplified controllers can often have near optimal performance. It is then shown that problems involving dynamic controllers of specified structure can be transformed into structured state feedback problems.
01 Nov 1977
TL;DR: In this paper, a procedure is reviewed whereby intractable equations can be replaced, or modeled, by substitutes which are readily treated analytically, thus permitting both the generation of system responses and the analysis of system stability.
Abstract: When a system has a periodically time variable component or parameter it is described by a differential equation with periodically varying coefficients, often of second order. Unfortunately many of these equations are intractable thus precluding convenient analysis of the corresponding "parametric" system; in such cases recourse is generally taken to numerical techniques. In this article a procedure is reviewed whereby intractable equations can be replaced, or modeled, by substitutes which are readily treated analytically, thus permitting both the generation of system responses and the analysis of system stability. It is shown that the principal requirement for this technique is to replace the time variation in the equation by another time function which resembles the former in its lower frequency spectrum and, in addition, leads to a solvable equation. The results presented illustrate how quite crude models of this sort can be used to produce very accurate results, for processes such as parametric amplification, in a fraction of the time required by numerical techniques.
TL;DR: Three species of the subgenus Hirtodrosophila, two with patterned wings and one without, that show lek behaviour are reported on.
Abstract: LEK behaviour, or the use of courting territories, is well known in the patterned wing, Hawaiian species of the subgenus Drosophila, but not elsewhere in the genus1. Australian Drosophila comprise a major adaptive radiation in the subgenus Scaptodrosophila, and minor radiations in Hirtodrosophila and Sophophora2,3. We report here on three species of the subgenus Hirtodrosophila, two with patterned wings and one without, that show lek behaviour.
TL;DR: In this paper, three new reports of stranded melon-headed whales (Peponocephala electra) on the east coast of Australia are described, and the skull was obtained from one animal, but full body measurements and other data were taken from the other two.
Abstract: Three new reports of stranded melon-headed whales ( Peponocephala electra ) on the east coast of Australia are described. Only the skull was obtained from one animal, but full body measurements and other data were taken from the other two. Detailed life history data and osteology were obtained from one of those.
It appears from this and an earlier report of a mass stranding of melon-headed whales on the coast of New South Wales that Peponocephala electra is a schooling species that is not rare on the northern half of the east coast of Australia. The scanty evidence suggests that maximum length of males is 2.7 to 2.8 meters.
TL;DR: Klossiella equi in the kidney of a horse was asymptomatic and caused only minor renal damage and inflammation.
Abstract: Klossiella equi in the kidney of a horse is described. Gametocytic and sporogonic stages were observed in the epithelium of the collecting tubules in association with schizonts in the glomeruli and proximal convoluted tubules. The condition was asymptomatic and caused only minor renal damage and inflammation.
TL;DR: This article explored the relationship of educational achievement to overt (the directly observable) and covert (the psychological) measures of acculturation for 190 high school seniors from American Samoa using canonical variate analysis.
Abstract: The relationship of educational achievement to overt (the directly observable) and covert (the psychological) measures of acculturation was explored for 190 high school seniors from American Samoa using canonical variate analysis. Three statistically significant and situationally interpretable relationships were found to exist between the overt and covert sets of variables, indicating that multiple acculturative approaches were operating simultaneously within Samoan adolescent culture. Educational achievement was found to be related mainly to the modern man approach to acculturation, the only approach to cross-validate. The study emphasized the probable multivariate nature of the acculturation process and the importance of verifying hypotheses through cross-validation.
TL;DR: Perithecia failed to form when glucuronic acid was the sole carbon source, perhaps due to the development of alkaline conditions.
Abstract: Ammonium ion is apparently essential for ascus and ascospore formation in Calonectria camelliae Shipton & Booth; infertile perithecia developed in the presence of nitrate or nitrite ions. A wide range of carbon sources stimulated the development of fertile perithecia, maltose clearly being the most effective. Perithecia failed to form when glucuronic acid was the sole carbon source, perhaps due to the development of alkaline conditions. Sucrose carbon levels of 4 g/1 gave optimum perithecial numbers when the C : N ratio was 10:1; the optimum C : N ratio was 15:1 when sucrose and ammonium nitrate were the C and N sources, respectively.
TL;DR: Shallow refraction techniques have an advantage over continuous profiling systems where marine environments preclude the use of this equipment or when cost is a restrictive factor as mentioned in this paper. But, their performance in the coastal environment is limited.
Abstract: Shallow refraction techniques have an advantage over continuous profiling systems where marine environments preclude the use of this equipment or when cost is a restrictive factor. Operational problems peculiar to the use of the portable refraction seismograph in the coastal environment are discussed using field examples from the Great Barrier Reef Australia.
TL;DR: Pulse width modulation during mass sweeping in a rectangular-excited quadrupole mass filter is shown to be of benefit in offsetting mass discriminatory effects and in implementing novel scan techniques.
TL;DR: It is concluded that addition of arginine may lead to the synthesis in the chloroplast of specific polypeptides necessary for nucleic acid synthesis and cell division.
Abstract: SUMMARY
The ability of L-arginine to stimulate autospore production in heterotrophic cultures of the Emerson strain of Chlorella is reversed by chloramphenicol. The antibiotic does not affect the uptake of glucose, neither does it alter significantly the pattern of incorporation of radioactivity from 14C glucose into the major fractions of arginine-treated cultures. The inhibitory effect of the antibiotic is largely restricted to those aspects of development which specifically respond to arginine. Thus, the stimulation of DNA synthesis by arginine is strongly reversed by chloramphenicol suggesting the involvement of some chloroplast-centered event. Chloramphenicol does not inhibit the uptake of arginine but affects the subsequent metabolism of the amino acid. It is concluded that addition of arginine may lead to the synthesis in the chloroplast of specific polypeptides necessary for nucleic acid synthesis and cell division.
TL;DR: Testosterone and estradiol increased aggressiveness in male lizards and caused shifts in dominance and Adrenaline caused a temporary increase in activity and agressiveness but no change in social structure.
Abstract: In order to ascertain whether hormones influence social organization of lizards, caged Sphenomorphus kosciuskoi were studied both before and after treatment with testosterone, estradiol, adrenaline and thyroxine. Testosterone and estradiol increased aggressiveness in male lizards and caused shifts in dominance. Adrenaline caused a temporary increase in activity and agressiveness but no change in social structure. Thyroxine did not affect social behaviour.
TL;DR: In this article, an active realisation of a general 2nd-order allpass function is proposed and compared with a similar structure using a lossy-inductor simulation technique, and it is shown that the proposed section can be adjusted by using a minimum number of controls and has a relatively unrestricted Q-factor capability, combined with a low sensitivity to amplifier-gain variations.
Abstract: An RC active realisation of a general 2nd-order allpass function is proposed and compared with a similar structure using a lossy-inductor simulation technique. It is shown that the proposed section can be adjusted by using a minimum number of controls and has a relatively unrestricted Q-factor capability, combined with a low sensitivity to amplifier-gain variations.
TL;DR: In this paper, a lossy-integrator implementation of any of the common biquadratic transfer functions is presented, employing three isotopic dual-input active blocks, and the principal advantage offered by the proposed canonic networks is that the intrinsically stable active blocks may be trimmed in isolation using simple gain and phase measurements made at a single frequency.
Abstract: A lossy-integrator realization of any of the common biquadratic transfer functions is presented, employing three isotopic dual-input active blocks. The principal advantage offered by the proposed canonic networks is that the intrinsically stable active blocks may be trimmed in isolation using simple gain and phase measurements made at a single frequency. The networks possess low or zero passive-element Q sensitivities and have low-frequency sensitivities combined with a lossy-capacitor tolerance. In addition, high-tolerance capacitors may be incorporated into the design in a straightforward manner.