Showing papers by "James Cook University published in 1975"
TL;DR: The cell-free rumen liquor of a steer on a diet of spear grass has been shown to contain macromolecular substances in which carbohydrates and lignin-derived compounds are covalently bound to each other.
108 citations
TL;DR: A culture isolate of the fungal plant pathogen Ceratocystis paradoxa produces at least five extra-cellular hemicellulases when grown on a medium containing a commercial hemiceLLulose as inducer, and one of the enzymes is deduced to be an endo-enzyme.
77 citations
01 Jan 1975
TL;DR: The chemoreceptors are distributed over the body surface, but concentrated at the anterior end, as in other decapod Crustacea, and when stimulated by food odour in flowing water, P. merguiensis moves against the current.
Abstract: Penaeus merguiensis detects food and discriminates it from non‐food particles by chemo‐sensory mechanisms. Vision was not found to play any part in the process. Food seeking behaviour is initiated by low concentrations of organic compounds (10‐5‐10‐6 Molar solutions of a range of amino acids) in the water, but higher concentrations (10‐1‐10‐2M) are needed to produce a masticating reaction by the mouthparts. The stimuli for mouthpart action and food seeking behaviour are not specific, the responses resulting from a wide range of amino acids. The chemoreceptors are distributed over the body surface, but concentrated at the anterior end, as in other decapod Crustacea. When stimulated by food odour in flowing water, P. merguiensis moves against the current. The reaction is a true rheotaxis, not mediated by vision. In still water, food location is less efficient. A chemotactic mechanism may operate, but is effective only over very short distances (a few centimetres).
74 citations
TL;DR: In this paper, the diffusion through hyaluronate solutions of six linear polymer fractions with molecular weights between 31000 and 530000 has been investigated, and the results suggest that asymmetric particles and coiled molecules preferentially penetrate the network by end-on movements as this offers fewer obstacles in their path than a random movement of whole hydrodynamic units.
Abstract: The diffusion through hyaluronate solutions of six linear polymer fractions with molecular weights between 31000 and 530000 has been investigated. The polymers (sodium deoxyribonucleate. polyadenylate, polyvinyl hydrogen phthalate and polyanethol sulfonate) absorb ultraviolet light and their diffusion could therefore be registered in synthetic boundary cells in the analytical centrifuge with the aid of a photoelectric scanning system, without interference from the hyaluronate.
The presence of hyaluronate retarded the diffusion of the polymers. The data could be fitted to a relatinship for the retardation of globular particles in polymer netweorks described by Laurent, Bjork, Pietruszkiewicz, and Persson (1963), which has recently been supported by theoretical work of Ogston, Preston, and Wells (1973). The linear polymers were, however, less retarded in the hyaluronate network than globular particles of equal hydrodynamic dimensions. The results suggest that asymmetric particles and coiled molecules preferentially penetrate the network by end-on movements as this offers fewer obstacles in their path than a random movement of whole hydrodynamic units. For a rigid rod this could lead to a unidimensional diffusion in the polymer network.
55 citations
TL;DR: The Undara Volcano as discussed by the authors formed lava fields covering 1,500 km2 with a volume of approximately 23 km3 and one of the flows extended 160 km on a gradient that averaged only 0.3°.
Abstract: The Undara Volcano erupted 0.19 m.y. ago and formed lava fields covering 1,500 km2 with a volume of approximately 23 km3. One of the flows extended 160 km on a gradient that averaged only 0.3°. This great length was a result of very high effusion rates, favourable topography and lava tube efficiency.
49 citations
TL;DR: Reductions in the relative volumes of germinal cells, Sertoli cells, tubular cytoplasm and parenchyma, and in tubular surface to testis volume ratios with advancing age, indicated a decrease in the capacity per unit volume of testis to produce sperm.
34 citations
01 Jan 1975
TL;DR: In this paper, a similarity measure calculated from the number of shared subtrees is found to satisfy the requirements of a "coefficient of similarity" to compare the shapes of two trees.
Abstract: A taxonomist may use rooted trees to depict hierarchical classifications of species belonging to the same family. We look at various properties which might be required of a "coefficient of similarity" to be used to compare the shapes of two such trees. A similarity measure calculated from the number of shared subtrees is found to satisfy these requirements.
34 citations
TL;DR: In this article, the authors show that the dependence of the termination rate on the viscosity of the polymerization medium has a relatively minor effect on the activation energy of N-vinyl pyrrolidone.
Abstract: Polymerization rates of N-vinyl pyrrolidone and corresponding activation energies depend on the nature of the polymerization solvent. This is mainly due to the influence of solvent polarity on the propagation reaction. The dependence of the termination rate on the viscosity of the polymerization medium has a relatively minor effect.
30 citations
01 Jan 1975
TL;DR: The McBride Volcanic Province of northern Queensland covers an area of about 5000 km2, and is composed of basaltic lava flows erupted from many large and small volcanoes.
Abstract: The McBride Volcanic Province of northern Queensland covers an area of about 5000 km2, and is composed of basaltic lava flows erupted from many large and small volcanoes. An older series of basalts, preserved in mesas, have K‐Ar ages in the range 7.3 to 7.8 m.y., late Miocene. Most of the volcanic rocks of the Province were erupted in the interval from 2.7 m.y. ago (late Pliocene) to almost the present day. No significant break in the volcanism is recognized during this younger period of activity. The K‐Ar ages are consistent with the stratigraphical control, based mainly on geomorphological evidence.
25 citations
TL;DR: Four neutral oligosaccharides, isolated by preparative paper chromatography, were shown by enzymic and methylation techniques to constitute a series of beta-(1 leats to 4)-D-xylose and O-alpha-L-arabinofuranosyl-(1 leads to 3)-O-beta-D-Xylopyranosyl--(1Leads to 4- Xylose), respectively, the latter being a new compound.
21 citations
TL;DR: In this paper, it was shown that the amorphous and crystalline regions of cellulose are attacked at approximately the same rate, and the molecular weight of remaining cotton decreases only slowly during digestion, and polysaccharide retains its fibrous form.
TL;DR: A microplate test was developed for the determination of neutralizing antibody titers against porcine parvovirus and was proved to be highly sensitive and reproducible.
Abstract: A microplate test was developed for the determination of neutralizing antibody titers against porcine parvovirus. End points were read directly by using haemagglutination techniques. The test was proved to be highly sensitive and reproducible.
TL;DR: In this article, the authors measured pressure fluctuations on the windward and leeward faces of a 43m-high building situated in a relatively exposed location and made measurements of velocity fluctuation on the top of the building.
TL;DR: Pregnancy rate varied little with season, but the highest percentages of cows pregnant in the first and third trimesters were recorded in autumn and spring, respectively, and most cows found non-pregnant had active ovaries at time of slaughter.
Abstract: A total of 7495 postpuberal beef cows from herds in north Queensland and the Northern Territory were examined at abattoirs to define the extent of wastage due to the slaughter of pregnant cows. On the basis of examination of teeth most cows (57%) were considered mature (approximately 3.5 to 7 years) at slaughter; 14% were young (9 months to 3.5 years) and 29% were old (over 7 years). In herds where pregnancy diagnosis by rectal examination had not been used at time of culling, 71.6% of slaughtered cows were pregnant and 42% of these cows were in the second trimester. This high pregnancy rate was considered an important source of herd wastage. Pregnancy rate varied little with season, but the highest percentages of cows pregnant in the first and third trimesters were recorded in autumn and spring, respectively. Most cows found non-pregnant had active ovaries at time of slaughter. Anoestrus was observed to be most common in winter and in old cows. Lactational status was not recorded. Mean cold carcase weight of 4229 cows was 161 +/- 40 kg. Maximum carcase weight was observed in cows slaughtered at 4 to 6 years of age; old cows had the lowest carcase weight (147 +/- 31 kg) of the age groups considered. Highest (170 +/- 43 kg) and lowest (135 +/- 41 kg) carcase weights in relation to pregnancy or ovarian status were observed in non-pregnant/ovary-active and non-pregnant/anoestrus cows respectively. Carcase weight of cows in the third trimester (165 +/- 35 kg) was greater than in the second (161 +/- 35 kg) or first (157 +/- 36 kg) trimesters; difference between the first and third trimesters was significant (P less than 0.01).
TL;DR: In this article, a technique for approximating solutions to the Mathieu equation from solutions to versions of the Hill equation known to be analytically tractable is presented, which is of value in computer simulations of the operation of the conventional, sinusoidally-operated quadrupole mass filter.
01 Jan 1975
TL;DR: The structure of tetraacetylethane has been determined by neutron diffraction as discussed by the authors, and the compound exists in the dienolic form, the enolic hydrogen being intramolecularly bonded to a neighbouring oxygen in a clearly asymmetric mode.
Abstract: The structure of tetraacetylethane has been determined by neutron diffraction. The compound exists in the dienolic form, the enolic hydrogen being intramolecularly bonded to a neighbouring oxygen in a clearly asymmetric mode. The acetylacetonate residues are essentially planar.
TL;DR: Experimental nasal and conjunctival infection of 18 heifers pregnant for 3, 5 or 7 months with a genital strain of IBR virus caused mild rhinitis or conjunctivitis in all inoculated animals and virus was recovered from 14 animals at 8 days after inoculation.
Abstract: Natural venereal infection of heifers with IBR virus resulted in vulvovaginal lesions in 9 of 12 heifers at 3 weeks after introducttion to bulls, and virus was isolated from 5 of the 9 affected animals. The infection was not associated with any effect on conception. Experimental nasal and conjunctival infection of 18 heifers pregnant for 3, 5 or 7 months with a genital strain of IBR virus caused mild rhinitis or conjunctivitis in all inoculated animals and virus was recovered from 14 animals at 8 days after inoculation. No effects on pregnancy were recorded.
TL;DR: In this paper, the model of a quadrupole mass filter which uses a piecewise-constant coefficient as an approximation to the sinusoid in the Mathieu equation is considered with regard to determining the minimum number of steps required and their values.
TL;DR: The osphradium in the genus Conus is a prominent bi-lamellate structure lying in the mantle roof near to the base of the siphon and fine structural examination shows that the component cells are organised into a peripheral and a central region.
Abstract: The osphradium in the genus Conus is a prominent bi-lamellate structure lying in the mantle roof near to the base of the siphon. Fine structural examination shows that the component cells are organised into a peripheral and a central region. The peripheral region consists of pigmented epidermal cells forming prominent ridges between which are grooves, at the sides of which lie the sensory cells, protected in clefts. The central region is clearly differentiated from the peripheral by a prominent basement membrane. This region contains smooth muscle, paired nerve trunks and a discrete area of cells containing numerous, dense, cored vesicles.
01 Jan 1975
TL;DR: In this paper, a simple design method is outlined for slopes made of strain-softening material or where such strain softening material exists in layers in critical zones, and the method entails using a simple clastic model to express the stress conditions responsible for initiating failure along a horizontal or sloping surface.
Abstract: A simple design method is outlined for slopes made of strain-softening material or where such strain-softening material exists in layers in critical zones. The method entails using a simple clastic model to express the stress conditions responsible for initiating failure along a horizontal or sloping surface. Following initiation it is assumed that further collapse will occur in a third order mechanism. Four case histories are examined -- an experimental coal stockpile, an overburden dump, the Aberfan waste-tip collapse and the Vaiont slide. In each case the method predicts failure while the values of factor of safety using conventional (circular or noncircular arc) methods range from 1.3 to 2, implying safety in all cases.
01 Mar 1975
TL;DR: In this paper, aversive conditioning as a means of reducing aggressive behaviour is discussed. But the authors focus on the negative effect of the conditioning on the human brain and do not consider the positive effect on the brain.
Abstract: (1975). Aversive conditioning as a means of reducing aggressive behaviour. Australian Psychologist: Vol. 10, No. 1, pp. 45-49.
TL;DR: The asexual structures are described; no sexual structures have been found despite extensive contrasts with members of the genusAbsidia andGongronella.
Abstract: Halteromyces radiatus is described as a new genus and species in the order Mucorales. The genus is referred to the family Mucoraceae and has close affinities to the genusAbsidia. The fungus grows readily in pure culture. The asexual structures are described; no sexual structures have been found despite extensive contrasts with members of the genusAbsidia andGongronella.
01 Jan 1975
TL;DR: In this article, a paradigm for "social incompetence" is proposed, which denotes specific behaviours of an actor which are judged by an arbiter to possess a degree of social unacceptability.
Abstract: SummaryA paradigm for ‘social incompetence’ is proposed. Certain predictions educed from the paradigm were tested. It is proposed that ‘social incompetence’ denotes specific behaviours of an actor which are judged by an arbiter to possess a degree of social unacceptability. However, whether or not a particular behaviour is labelled incompetent by an arbiter is a function of the interaction of the behaviour's unacceptability and its perceived rate of occurrence.At one extreme of a continuum are behaviours having low unacceptability but which need high rates of occurrence to be labelled socially incompetent. At the other extreme are behaviours that have high unacceptability but which require only low rates of occurrence to be labelled incompetent.Arbiter groups of counsellors, parents and adolescents, and forty selected ‘behaviours’ were used to test the paradigm in respect to adolescent behavioural repertoires. Effects of intentionality and the normative character of certain behaviours were investigated.
TL;DR: It is suggested that interdisciplinary studies, a substantial upgrading in the emphasis on animal production, and the inclusion of sociology could be influential factors in improving the efficiency of veterinary services.
TL;DR: It is proposed that Polysegmentina is a junior synonym of Hauerina and the morphology taxonomy and distribution of H. circinata, H. fragilissima and H. pacifica (Cushman) are discussed with special reference to North Queensland faunas.
Abstract: Summary The genus Hauerina is redescribed. It is proposed that Polysegmentina is a junior synonym of Hauerina. The morphology taxonomy and distribution of H. circinata Brady, H. fragilissima (Brady) and H. pacifica (Cushman) are discussed with special reference to North Queensland faunas. H. diversa Cushman is shown to be a junior synonym of H. circinata, H. bradyi Cushman a junior synonym of H. fragilissima and H. pacifica rugosa Collins and H. serrata Cushman junior synonyms of H. pacifica Discussions of the phylogenetic relationships within Hauerina and affinities with other genera as well as the significance of certain aspects of test morphology in classification are presented.