Showing papers by "Griffith University published in 1982"

Characteristics of lactic acid bacteria isolated from vacuum packaged beef

Abstract: The characteristics of 177 psychrotrophic lactic acid bacteria isolated from vacuum-packaged fresh beef have been studied. Eighteen isolates were identified as Leuconostoc mesenteroides and the remainder were lactobacilli. None of these could be identified down to a species level and they were considered to be atypical streptobacteria or atypical betabacteria. Atypical streptobacteria produced both isomers of lactic acid and did not ferment lactose and maltose. Atypical beta-bacteria produced only L(+) lactic acid. The nature of the isolates varied considerably from pack to pack. The API 50 lactobacillus identification system proved useful in studying these organisms.

Detection of imogolite in soils using solid state 29 Si NMR

Abstract: High resolution solid state 29Si-NMR has recently been used to examine silicates, and synthetic and natural zeolites1–4. This has been possible through the use of dipolar decoupling, magicangle spinning and cross-polarization techniques which have enabled line narrowing and also considerable signal enhancement for 29Si nuclei in close proximity to protons. It has been found that isotropic 29Si chemical shifts in solids and solutions are generally similar and depend mainly on the degree of condensation of silicon–oxygen tetrahedra1 For silicates, increasing condensation from single (Q0, −66 to −72 p.p.m.) to double tetrahedra (Q1, −78 to −82 p.p.m.), to chains (Q2, −86 to −88 p.p.m.) and cyclic layered structures (Q3, −107 to −109 p.p.m.) leads to increasing diamagnetic shielding. In solid aluminosilicates, the 29Si chemical shift is sensitive to the substitution of aluminium. A further important point was that the 29Si linewidth in aluminosilicates is sensitive to the regularity of aluminium distribution in the lattice. Thus 29Si-NMR has obvious potential for the elucidation of the coordination of silicon in soils and mineral components. We report here the first 29Si-NMR study of the clay mineral imogolite, and show that 29Si-NMR is an excellent analytical technique for the identification of imogolite (or imogolite like materials, that is proto-imogolite) in clay fractions. The observed chemical shift of imogolite (−78 p.p.m.) is consistent with the proposal that imogolite is a tubular hydrated aluminosilicate in which silicon tetrahedra are isolated by coordination through oxygen with three aluminium atoms and one proton.

Temperature and rate of development in danaus plexippus l. and d. chrysippus l. (lepidoptera:nymphalidae)

Abstract: Population processes and interactions among insects are mediated by thermally driven physiological time scales. The effects of temperature on developmental rates in Danaus plexippus and D. chrysippus were determined by rearing individuals under a range of constant temperatures. Rates of development changed in a linear fashion over a wide range of temperatures. The linear model accurately predicted development times under fluctuating temperatures for D. plexippus. The effect of this thermal time scale on competition between the 2 species is discussed.

Plants, Sites and Domiculture: Aboriginal Influence upon Plant Communities in Cape York Peninsula

Abstract: This paper explores certain relationships between Aborigines and plants as they have applied along the east coast of Cape York Peninsula and attempts to provide an explanation of effects upon the plant environment that resulted from a long and complex interaction between these people and specific sites. Their knowledge and manipulation of plants is neither simple nor 'pre-agriculturaT, and can only be understood by detailed study of the particular cultural and biological systems within which they operate. These patterns can be extremely dynamic and can affect both people and environment through occupational continuity. Most importantly, some plant communities may have been not merely modified but created by Aboriginal cultural activity. Aboriginal interactions with plants are the outcome of strategies which include not only physical resource exploitation, but as well systems of locality and territoriality that recognize ties between particular individuals and groups and particular home environments.

Temporal and spatial variation of mortality in field populations of Danaus plexippus L. and D. chrysippus L. Larvae (Lepidoptera: Nymphalidae).

Abstract: Mortality estimates for the immature stages of two butterfly species, Danaus plexippus and D. chrysippus, were obtained by observing the survival of egg cohorts on different sized patches of food plants (Asclepias spp.), over a one-year period. Losses were variable (0–100%) but usually high (90% and over) throughout the year for both species. Most of the losses in both species occurred in the early stages. The mortality by the third instar accounts for 86–100% of the total losses by instar V. Accordingly both species fall into Price's (1975) type A survivorship category. The size of patches of host plants affected losses. The trend was for increasing losses with increasing patch size. A full life-budget is presented for D. plexippus and implications of the observed mortality levels for competition between the two butterfly species is discussed.

Actin in human spermatozoa.

Abstract: An actin-like material was extracted from human spermatozoa. The material comigrated with actin on sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis, and showed specific affinity for myosin. Purified anti-actin antibodies were used to localize actin to the posterior region of the sperm head and to the connecting piece, midpiece and mainpiece of the tail. Determination of the function of sperm actin requires further investigation.

The Analysis and Description of Movement in Adult Danaus Plexippus L. (Lepidoptera: Danainae)

Abstract: [1. Interactions among flying butterflies, Danaus plexippus, and various densities and dispersions of their milkweed food-plants, Asclepias spp., have been studied using a continuously recording tracking device. 2. Study areas comprising within-patch and edge plants and areas with no plants were not treated uniformly by the butterflies. Regions with plants were visited more frequently than those without and the greatest range of behavioural activities, basking, feeding and ovipositing, occurred about the plants themselves. There was also a geographical bias in usage by both sexes. 3. Distributions of straight line headings of butterfly tracks (i.e. lines joining the first and last points of a recorded track) did not differ from uniformity for either males or females. 4. Incident angles for females but not for males were significantly biassed geographically. 5. Males divided their time equally between flying and pausing and their pauses were made up equally of feeding and basking. 6. Females spent 25% of their time flying and 75% pausing, these pauses comprising approximately 75% basking, 10% egg-laying and 15% feeding. 7. Transitions between particular behavioural states were not all equally likely for females. An oviposition was most likely to be followed by another oviposition or basking; a bask by an oviposition. 8. The mean vectors of tracks in the horizontal plane based on an analysis of 0.75 s fixes along the continuous tracks had a mean direction (R1) of 0.37 for males and 0.22 for females with associated mean angle (ζ values of 0.98 and 1.04 respectively (statistics after BATSCHELET, 1965). 9. There was much less movement in the vertical plane with a mean absolute angle of turn of 8.5° (SD = 13.75) for males, and 12.9° (SD = 19.64) for females. 10. Speed of movement based on the distances moved between successive fixes was 2.38 m/s (SD = 1.15) for males and 1.43 m/s (SD = 0.54) for females. Males moved significantly faster than females. 11. The signs of angles turned through (i.e. left hand vs right hand turns) in successive segments of track were independent both at the first order (two segments) and third order (three segments) level, in both sexes. 12. Move lengths showed significant differences from homogeneity at both first and second order level when the moves were classified as above or below average for each sex. 13. Both sexes were more directional and faster when flying in the open than when within patches of food-plants. Differences in directionality among patch edge, patch centre, and single plant situations occur. The distribution of angles turned through is centred on 0° for males in all areas and is bimodal about 0° and ± 180° for females. This difference between sexes is ascribed to specific, food-plant related activities on the parts of the females. Other minor differences in flight patterns in different parts of the study area are noted. 14. The results of this work are used to draw up the 'rules of movement' for male and female adult D. plexippus and the biological significance of these rules for the resulting patterns of movement and resource usage are discussed., 1. Interactions among flying butterflies, Danaus plexippus, and various densities and dispersions of their milkweed food-plants, Asclepias spp., have been studied using a continuously recording tracking device. 2. Study areas comprising within-patch and edge plants and areas with no plants were not treated uniformly by the butterflies. Regions with plants were visited more frequently than those without and the greatest range of behavioural activities, basking, feeding and ovipositing, occurred about the plants themselves. There was also a geographical bias in usage by both sexes. 3. Distributions of straight line headings of butterfly tracks (i.e. lines joining the first and last points of a recorded track) did not differ from uniformity for either males or females. 4. Incident angles for females but not for males were significantly biassed geographically. 5. Males divided their time equally between flying and pausing and their pauses were made up equally of feeding and basking. 6. Females spent 25% of their time flying and 75% pausing, these pauses comprising approximately 75% basking, 10% egg-laying and 15% feeding. 7. Transitions between particular behavioural states were not all equally likely for females. An oviposition was most likely to be followed by another oviposition or basking; a bask by an oviposition. 8. The mean vectors of tracks in the horizontal plane based on an analysis of 0.75 s fixes along the continuous tracks had a mean direction (R1) of 0.37 for males and 0.22 for females with associated mean angle (ζ values of 0.98 and 1.04 respectively (statistics after BATSCHELET, 1965). 9. There was much less movement in the vertical plane with a mean absolute angle of turn of 8.5° (SD = 13.75) for males, and 12.9° (SD = 19.64) for females. 10. Speed of movement based on the distances moved between successive fixes was 2.38 m/s (SD = 1.15) for males and 1.43 m/s (SD = 0.54) for females. Males moved significantly faster than females. 11. The signs of angles turned through (i.e. left hand vs right hand turns) in successive segments of track were independent both at the first order (two segments) and third order (three segments) level, in both sexes. 12. Move lengths showed significant differences from homogeneity at both first and second order level when the moves were classified as above or below average for each sex. 13. Both sexes were more directional and faster when flying in the open than when within patches of food-plants. Differences in directionality among patch edge, patch centre, and single plant situations occur. The distribution of angles turned through is centred on 0° for males in all areas and is bimodal about 0° and ± 180° for females. This difference between sexes is ascribed to specific, food-plant related activities on the parts of the females. Other minor differences in flight patterns in different parts of the study area are noted. 14. The results of this work are used to draw up the 'rules of movement' for male and female adult D. plexippus and the biological significance of these rules for the resulting patterns of movement and resource usage are discussed.]

Between two worlds: art and commercialism in the record industry

Abstract: This paper is concerned with the popular music press.* In particular it is an analysis of some of the premises which writers in the music press take for granted but which inform their imderstanding of, and attitudes to, the music about which they write. There is a series of presuppositions relating to popular music which, taken together, outline what I will call the discourse of popular music. It is the purpose of this paper to make a start at mapping these presu{>positions through an analysis of a series of interviews with journalists who work for the music press. Journalists can and frequently do disagree with each other about such things as what is or is not a good record or even about seemingly more fundamental points such as whether a record review should limit itself to discussing the music or whether it should give more general information about the performer with the implication that this is tmpOTtani for an understanding of the music. Thus a critic on one paper says: ^

Vibrational relaxation in ground state p‐difluorobenzene: Single level preparation by stimulated emission pumping

Abstract: We have measured the cross section for vibrational relaxation from the 52302 level (evib = 2036 cm−1) of S0 p‐difluorobenzene (pDFB) due to pDFB‐pDFB collisions. Stimulated emission pumping has been used to selectively populate the 52302 level. Single vibronic level fluorescence from the S1 level 302, generated by exciting the 5023022 transition at a variable delay time after 52302 has been populated, has been used to monitor the population dynamics of 52302. We obtain a value of 4±1×107s−1 Torr−1 for the vibrational relaxation rate coefficient, a value which is 2–3 times the hard sphere value. This large cross section is consistent with the cross sections observed in S1 benzene but is an order of magnitude larger than the cross sections observed previously for a variety of molecules in the ground electronic state. (AIP)

Island Population, Land Area, and Climate: A Case Study of the Marshall Islands

Abstract: A major difficulty in the study of the relationship between human population size and the environment has been placing the problem in a testable framework. Using data from the Marshall Islands, this article tests the proposition that population size and density are highly correlated with environmental variables, including rainfall and land area, through a complex series of socially mediated regulatory mechanisms. This analysis thus supports the population-resources disequilibrium theory of culture change.

A Tax Evasion Model with Allowance for Retroactive Penalties

Abstract: Discrete models of tax evasion are considered when evasion has occurred over a period of several years. Allowance is made for growth in income, investment of illicit gains from successful evasion, and the imposition of retroactive penalties. Retroactive penalties increase deterrence of evasion if introduced at a point where evasion has been continuing for some years, since the utility gain from continuing successful evasion is unaffected, whereas the utility loss will be increased regardless of attitude to risk. Prohibitive penalty rates are determined, and a range of penalty rates are given in which some dishonest taxpayers may become honest. The formulation of the basic model and consequent conclusions are relevant to the current Australian taxation scene.

Component analysis and modelling of the movement process: Analysis of simple tracks

Abstract: The construction of a general model of animal movement using the ‘experimental components' approach ofC. S. Holling is proposed. The process of ‘movement’ is interpreted very generally as any displacement of the whole organism in space. The rationale for modelling such processes rests upon the idea that there is a basic “canonical” pattern of movement characteristic of a species moving in a homogeneous environment, which pattern is overlaid by the various directional stimuli present in more usual heterogeneous environments.

Comparative studies of aldehyde oxidase, alcohol dehydrogenase and aldehyde resource utilization among Australian Drosophila species

Abstract: 1. 1. Alcohol dehydrogenase (ADH) and aldehyde oxidase (ALDOX) activities are compared among 20 cosmopolitan and endemic species of Australian Drosophila , representative of 4 subgenera and 9 species groups distinguishable by ecological criteria. 2. 2. Of these species, D. melanogaster, D. simulans, D. immigrans, D. inornata and D. hibisci have also been examined for their capacities to utilize and tolerate environmental acetaldehyde. 3. 3. Those species attracted to fermented fruit-baits exhibited intermediate to high ADH activities and were able to utilize and tolerate acetaldehyde, whereas those species collected by sweeping in rain forests, aspirated from Hibiscus flowers and that utilize fungi as a resource, exhibited low ADH activities and were unable to use acetaldehyde as a significant resource. 4. 4. ALDOX activities, however, did not correlate with the acetaldehyde utilization characteristics of the organisms which may indicate that another enzyme catalyses this reaction in vivo . 5. 5. Population genetic analyses of ALDOX isozymes in D. enigma, D. nitidithorax and D. specensis provided evidence for 2 Aldox structural genes. The distribution of ALDOX isozymes among the 20 Australian Drosophila species was investigated by comparative electrophoretic analyses. 6. 6. A possible role for ALDOX in Drosophila in the detoxification of plant heterocyclic compounds is discussed.

On the turnover and multiplicity of peroxisomal catalases.

Abstract: Among the more unusual biological characteristics of mammalian catalases are the occurrence of a marked variation in the microlocalization and multiplicity of the enzyme between homologous tissues in different species and the distinctive differences in the turnover characteristics of these catalases.'.' While most of the contemporary work on peroxisomal biogenesis in vertebrates has focused on the situation in rat some cognizance of these interspecies variations is also required for a full understanding of the complex biological phenomena involved in topogenesis and turnover; and in the present contribution, attention is drawn to the manner in which an examination of the characteristics of mouse liver catalase has allowed significant comment on a number of features of peroxisomal biogenesis and turnover that have proved to be refractory to analysis in other biological systems. These observations have been integrated into an overall model, which relates the nature and sequence of the changes of catalase structure during synthesis and degradation, and which serves to complement and augment the work of other groups on the turnover of this organelle.

Isotope-selective laser analysis of the electron-impact excited 6 1 S 0 →6 1 P 1 transition of mercury: A test of the Percival-Seaton hypothesis

Abstract: An isotope-selective technique has been used to measure line polarizations in the range 7.5 to 12.0 eV for the electron-impact--excited 185-nm transition of atomic mercury. Measurements were made on the I = 0 and I = 1/2 nuclear-spin isotopes. A stepwise excitation technique was used involving electron excitation followed by single-mode laser excitation. The results obtained indicate a breakdown in the Percival-Seaton hypothesis near threshold.

Formalization of the basic concepts of animal ecology

Abstract: Formal definitions of the following concepts of animal ecology are given: environment, niche, locality, local population, natural population, community, ecosystem. Five primitive (undefined) notions are used including “animal”, “offspring” and “habitat”, the latter in the sense of Charles Elton. The defining equations for the environment of one animal are first given, then niche (in the Elton sense) is formally defined in terms of the environment. The fifth primitve notion “habitat” is then introduced in order to define the remaining concepts.

The surface layer formed on zinc-containing glass during aqueous attack

Abstract: The glass-water interaction is reviewed via an outline of the processes of bulk dissolution, selective leaching and surface enhancement. Special attention is paid to the nature and effects of surface films. Glasses of three compositions, each containing about one-fifth by weight Zn, are subjected to aqueous attack. Solution analysis confirms the roles of Na, Si and Zn in leaching, dissolution and surface enhancement, respectively. Proton-induced X-ray emission corroborates Zn enhancement in the glass surface and X-ray photoelectron spectroscopy fixes the Zn build-up to the first few nanometres. Powder X-ray diffraction examination identifies the specific structures of hemimorphite and Zn orthosilicate while transmission electron microscopy finds such phases to be distributed in a largely amorphous matrix. Infrared spectra are consistent with the presence of a modified silicate structure and additionally indicate that water is loosely bound in the reacted surface layer. Attack of a non-Zn glass by a Zn-containing solution shows the ion in solution produces a Zn surface layer while attack of a Zn glass by a Zn complexing solution shows a Zn layer forms preferentially to complexation. Hence Zn, in either the solid or solution, induces a thin, protective, solvated and partially crystalline silicate zone on a glass under aqueous attack.

A Sociological Approach to Fraud in Science

Abstract: This paper extends sociological theory into the controversial area of the presentation of fraudulent scientific results. Although representative evidence does not exist, sufficient cases are known to reveal that fraud is not uncommon in science.Using a 'systems' approach first, areas appear within science and on its periphery where the scientific community's sanctions are inoperative. On the margins of science, these categories include 'hired hands', pseudo-scientists and industrial scientists. Within the scientific community the lack of guaranteed detection of fraud also creates circumstances where sanctions are inapplicable.Within this framework, the 'action' approach indicates possible factors motivating individuals toward fraud. For many groupings, a major factor appear to be a commitment to a theory so strong that it overrides disconfirmation, and diminishes fears of detection. Other factors include career considerations and political views.In each case evidence is produced to show, prima facie, that...