Showing papers by "University of Queensland published in 1981"
919 citations
TL;DR: A BASIC computer program for performing weighted nonlinear regression is described and it is shown that the program is useful for the analysis of data conforming to the Michaelis-Menten equation, a single exponential, and to binding equations.
539 citations
TL;DR: In a comprehensive study of the behaviors and correlates of information seeking by Australian new car buyers as mentioned in this paper, the authors examined three dimensions of information-seeking behavior, i.e., three sources of information for information seeking.
Abstract: In a comprehensive study of the behaviors and correlates of information seeking by Australian new car buyers, the authors examine three dimensions of information seeking—a sources of information di...
402 citations
TL;DR: Recogn recognition is made of higher levels of mental integration of information flows which, it is argued, must include parameters of past cultural and climatic experiences and expectations.
Abstract: Recommendations for indoor thermal requirements have been based upon verbalized responses on traditional assumptions that (1) minimal thermoregulatory activity may be equated to maximum subjective acceptability (2) sensations and levels of discomfort are synonymous and (3) perception of warmth is exclusively the function of thermal stimulus — physiological response. These concepts are reviewed in the light of recent researches which indicate the inadequacy of the existing physiological models and methods of research. In particular, recognition is made of higher levels of mental integration of information flows which, it is argued, must include parameters of past cultural and climatic experiences and expectations. The aim is to initiate a more holistic approach to research into human thermal environments, and, a clearer definition of concepts significant to practical application.
288 citations
TL;DR: Midazolam, a new water-soluble benzodiazepine, was administered as: i) 5 mg intravenously, ii) a 10-mg oral solution and iii) a10-mg Oral tablet, to six volunteers whose informed consent had been obtained.
Abstract: Midazolam, a new water-soluble benzodiazepine, was administered as: i) 5 mg intravenously, ii) a 10-mg oral solution and iii) a 10-mg oral tablet, to six volunteers whose informed consent had been obtained. Midazolam plasma concentrations were measured using an electron-capture gas-liquid chromatographic assay. After 5-mg intravenous midazolam, subjects fell asleep within 1–2 min and continued to sleep for an average of 1.33 h. After oral midazolam intake (solution or tablets), drowsiness appeared after a average of 0.38 h (range 0.25–0.55 h) and sleep continued for an average of 1.17 h. The time to reach peak plasma midazolam concentration after the 10-mg solution dose (0.37±0.45 h) did not differe significantly (‘t’=2.04, df=10,p>0.05) from the time to reach peak plasma midazolam level after the 10-mg tablet dose (0.74±0.45 h). The terminal half-life, (t1/2), of midazolam in plasma was 1.77±0.83 h and there was no significant difference between the mean terminal half-life values obtained for the three midazolam formulations. The mean total clearance (Cl), of midazolam after 5-mg intravenous administration was 0.383±0.094 l·kg−1·h−1. The first pass effect, F, determined experimentally (0.36±0.09) indicated the substantial first pass metabolism of midazolam. The percentage of the midazolam dose excreted unchanged in urine in four subjects during the 0-8-h urine collection interval was very small (0.011%–0.028%).
268 citations
TL;DR: In this paper, a review of these studies indicates that few if any, procedures may be defended on the grounds that they improve the quality of life (QOL) of the patient.
240 citations
TL;DR: A sample size of approximately 30 gastric mills, each at least 50% full, was determined empirically to be adequate for a description of natural diet.
225 citations
01 Jan 1981
TL;DR: In this article, all the finite strain equations that we are aware of that are worth considering in connection with the interior of the Earth are given, with the assumptions on which they are based and corresponding relationships for incompressibility and its pressure derivatives in terms of density.
Abstract: All the finite strain equations that we are aware of that are worth considering in connection with the interior of the Earth are given, with the assumptions on which they are based and corresponding relationships for incompressibility and its pressure derivatives in terms of density. In several cases, equations which have been presented as new or independent are shown to be particular examples of more general equations that are already familiar. Relationships for deriving finite strain equations from atomic potential functions or vice versa are given and, in particular it is pointed out that the Birch-Murnaghan formulation implies a sum of power law potentials with even powers. All the equations that survive simple plausibility tests are fitted to the lower mantle and outer core data for the PEM earth model. For this purpose the model data are extrapolated to zero temperature, using the Mie-Gruneisen equation to subtract the thermal pressure (at fixed density) and the pressure derivative of this equation to substract the thermal component of incompressibility. Fitting of finite strain equations to such zero temperature data is less ambiguous than fitting raw earth model data and leads immediately to estimates of the low temperature zero pressure parameters of earth materials. On this basis, using the best fitting equations and constraining core temperature to give an extrapolated incompressibilityK0=1.6×1011Pa, compatible with a plausible iron alloy, the following numerical data are obtained: Core-mantle boundary temperature 3770 K Zero pressure, zero temperature densities: lower mantle 4190 kg m−3 outer core (solidified) 7500 kg m−3 Zero pressure, zero temperature incompressibility of the lower mantle 2.36×1011Pa
170 citations
TL;DR: In this paper, a parametric element is formulated which enables the economic modelling of infinite domain type problmes, such as an opening in a stress field in an infinite medium, either in two or three dimensions.
Abstract: A parametric element is formulated which enables the economic modelling of ‘infinite domain’ type problmes. A typical problem is an opening in a stress field in an infinite medium, either in two or three dimensions. The strategy is to model around the opening with two or three layers of conventional isoparametric finite elements and surround these with a single layer of ‘infinite domain’ elements. Several sample problems has been analysed for circular, square and spherical openings in infinite media, and the results compared with either theoretical or boundary element solutions which include the ‘infinite’ boundary in their solution technique. Copyright
163 citations
TL;DR: The rate of emptying, expressed as half‐time (T1/2e) in minutes, was significantly longer in the elderly subjects compared to the young healthy volunteers, particularly with respect to the rate and extent of drug absorption in elderly persons.
Abstract: The effect of the aging process on gastric emptying was studied in 11 elderly subjects (mean age, 77) and in 7 young healthy volunteers (mean age, 26). Gastric emptying rates were assessed by a modified sequential scinti-scanning technique after administration of the nonabsorbable chelated radiopharmaceutical 99mTc-DTPA. The rate of emptying, expressed as half-time (T 1/2e) in minutes, was significantly longer (p less than 0.001) in the elderly subjects (mean apparent T 1/2e = 123.23 min) compared to the young healthy volunteers (mean apparent T 1/2e = 49.69 min). Clinical implications of these findings are discussed, particularly with respect to the rate and extent of drug absorption in elderly persons.
158 citations
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TL;DR: There are regular trees (as defined in the paper) which are nearly optimal among trees with a given number of nodes, and that minimal-cost trees are often nearly regular.
TL;DR: A new protozoan of the genus Perkinsus is described from the muscle and hemolymph of the blacklip abalone, Haliotis ruber, from South Australia, and appears to be uninfective to oysters.
TL;DR: Results indicated that the Instructions plus Feedback phase was sufficient to produce reduced levels of problem behavior at home and high levels of accurate implementation, but generalization effects out of home were equivocal.
Abstract: This study examined the generalization and maintenance effects of three phases of parent training (Instructions plus Feedback and two Self-management Training phases) on levels of disruptive child behavior and the accuracy with which parents implemented programs. Data were collected from five families in three main settings: the initial training setting (the home), a variety of generalization settings in the community, and the family breakfast. A multiple baseline across subjects design was used. Instructions plus Feedback comprised instructing parents to use a range of behavior management procedures and provided home-based differential feedback concerning accuracy of program implementation. Self-management Training phases involved training parents in goal setting, self-monitoring, and planning skills, specific to their performance of appropriate parenting skills in generalization settings. Results indicated that the Instructions plus Feedback phase was sufficient to produce reduced levels of problem behavior at home and high levels of accurate implementation, but generalization effects out of home were equivocal. Self-management maintained reduced levels of problem behavior at home but, in addition, resulted in generalization effects in community settings for both children and parents. Maintenance probes 3 months following the program revealed the effects had been maintained.
TL;DR: Proper assessment of factors such as libido and mating ability before breeding can greatly reduce the possibility of poor reproductive performance from single sires.
TL;DR: Infestations by the nematode Heligmosomoides polygyrus can prevent adult male mice from becoming behaviorally dominant and the effect is dose-dependent and is more likely to influence the development of dominance than to disrupt existing dominance relationships.
Abstract: Infestations by the nematode Heligmosomoides polygyrus can prevent adult male mice from becoming behaviorally dominant. The effect is dose-dependent and is more likely to influence the development of dominance than to disrupt existing dominance relationships. Doses capable of exerting this effect are not lethal and do not affect weight.
01 Oct 1981
TL;DR: In this article, a large-signal circuit model of a heterojunction injection laser is presented, which can be easily implemented on general-purpose nonlinear circuit analysis programs, and does not require specialised laser analysis software.
Abstract: A new large-signal circuit model of a heterojunction injection laser is presented. The model includes the current/voltage characteristics of the semiconductor heterojunction and the electro-optical dynamics of the active layer. It enables the laser and its electrical drive circuit to be analysed in a unified manner. The model can be easily implemented on general-purpose nonlinear circuit analysis programs, and does not require specialised laser analysis software. The model is illustrated with a number of simulated laser response characteristics.
TL;DR: The four, elongate midpiece elements of the mature euspermatozoon are apparently derived from the four large, spherical mitochondria of the euspermatid.
Abstract: The mesogastropod Pyrazus ebeninus, produces true spermatozoa (here termed euspermatozoa) and multi-flagellate, mobile cells (here termed paraspermatozoa). The mature paraspermatozoon consists of an elongateconical ‘head’ (6.5–8.5 μm in length), constructed of an electron-dense mosaic sheath surrounding a similarly dense, rod-shaped nuclear core (which runs almost the full length of the head). An acrosome-like structure forms the apex of the head. Five to eight axonemes are fixed to the posterior extremity of the nuclear core, each by means of an attachment complex (dense attachment rod, centriolar cap and centriole). A short (3–4 μm) ‘midpiece’ zone follows the head and consists of the multiple axonemes interspersed with very elongate mitochondria. A tuft of short (20 μm) tails (termed minor tails) emerges from the midpiece in addition to one very long tail (termed the major tail) ensheathed in dense granules which resemble glycogen granules. A single membrane surrounds head, midpiece and tails whilst the nuclear core retains the original double nuclear membrane. Developmentally, the multiple axonemes arise from one of a pair of wheel-shaped arrangements of centrioles and attach to posterior indentations in the nucleus prior to its transformation into the nuclear core. Dense vesicles, derived apparently from the endoplasmic reticulum, accumulate along and around the developing nuclear core and (in the presence of microtubules) condense into the mosaic head sheath. Cytoplasmic mitochondria elongate and collect at the posterior axis of the cell, where, together with the axonemes, they form the midpiece. Features not previously reported in other ultrastructural studies of paraspermatozoa include the acrosome-like structure of the head, the structure of the midpiece zone, the glycogen sheath of the major tail, the dense annular structure at the junction of the midpiece and major tail and the presence of microtubules in the final phase of head and midpiece maturation. Some features of the euspermatozoon are also described and the comparative ultrastructure of mature and developing paraspermatozoa and their possible functions in the Gastropoda, are reviewed.
TL;DR: In this paper, the authors show that the overstorey cover of a community reaches an equilibrium value determined largely by the prevailing climate, while the understorey coverage of all strata below the canopy attains a balance with over-storey FPC.
Abstract: Foliage Projective Cover of the overstorey (canopy) of a‘climax’community appears to reach an equilibrium value determined largely by the prevailing climate. Overstorey FPC decreases in‘climax’communities in a graded series from humid to arid regions.
Understorey cover (of all strata below the canopy) in‘climax’communities attains a balance with overstorey FPC. Disturbance (gaps, microhabitats, fire, overgrazing, invasion of woody weeds, etc.) may reduce the overstorey cover which will be compensated by an increase in understorey cover. Secondary succession back to the‘climax’structure will follow a path maintaining an inverse linear relationship between understorey cover and overstorey cover. At the same time, species diversity appears to decrease as overstorey cover increases.
TL;DR: Motion after-effects (MAEs) were measured intraocularly and interocularly when a rival stimulus caused perceptual suppression of the adaptation stimulus and non-rival adaptation was limited to the duration and adaptation stimulus was dominant in (a).
TL;DR: A strong relationship was found between faecal egg counts and the total number of adult H. contortus in sheep in the Goondiwindi area of south-east Queensland and was considered to be of value in the implementation of programmes for the diagnosis and control of haemonchosis.
TL;DR: Clinical evidence of iron overload was not observed in heterozygotes, and there was no biochemical or histological evidence of liver disease resulting from excessive iron stores, according to a study of 20 families with idiopathic hemochromatosis.
TL;DR: In this paper, a study was conducted to determine the impressions of an Australian-born audience to accented English speech and its effect upon judgments of the speakers' personalities, which indicated an interaction between sex and nationality of speaker on both dimensions.
Abstract: Eighty students, 40 male and 40 female, listened to tapes of male and female speakers from Australia, Britain, France, Greece, Italy, and Vietnam reading a short English passage. The aim of the study was to determine the impressions of an Australian-born audience to accented English speech and its effect upon judgments of the speakers' personalities. Factor analysis of the personality ratings revealed evaluative and dynamism dimensions. Results indicated an interaction between sex and nationality of speaker on both dimensions. Discussion focused on the combined influence of nationality and sex of speaker in eliciting impressions based on accented voices.
TL;DR: In this article, a statistical analysis of 1,100 km2 of overlapping sea floor and sea surface gravity data from the Gulf of Mexico (made available by Exxon) is presented.
Abstract: Measurements of the variation of gravity with depth in mines and boreholes permit the densities of intervening rock strata to be inferred. In the few cases in which reliable absolute values of density have been independently determined, the calculations can be used to check the value of the newtonian gravitational constant, G. Such large-scale measurements of G are important because the validity of the inverse square law of gravity at short range is being questioned. We have made such a series of measurements and have found four other data sets in the literature that suffice for the estimation of G. We also report here a statistical analysis of 1,100 km2 of overlapping sea floor and sea surface gravity data from the Gulf of Mexico (made available by Exxon). All these estimates of G give values that are higher than the conventional, laboratory-determined one. While the possibilities of systematic errors in these data sets preclude a definite conclusion that Newton's law of gravity fails at short range, the strong circumstantial evidence suggests that well controlled large-scale experiments on the inverse square law are urgently required.
01 Jan 1981-Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science
TL;DR: In this paper, a transition in product morphology from plate or lath magnetite to porous magnetite was found to occur at a constant free energy difference between the reducing gas mixture and the hematite over a range of reaction temperatures.
Abstract: The microstructures resulting from the reduction of hematite to magnetite have been examined for a wide range of temperatures and gas conditions. A transition in product morphology from plate or lath magnetite to porous magnetite was found to occur at a constant free energy difference between the reducing gas mixture and the hematite over a range of reaction temperatures. Direct observations of lath nucleation and growth are reported and show the self-accelerating effect of the Fe2O3 → Fe3O4 transformation. The limits of porous growth are discussed in terms of established theories of discontinuous precipitation and a mechanism for the formation of lath magnetite is proposed.
TL;DR: It was concluded that betamethasone therapy, under the conditions of the original trial, was not hazardous to cognitive development as measured in this study.
Abstract: The present study was part of a larger study investigating the long-term development of children of mothers included in a controlled trial of betamethasone therapy in preterm labor, the purpose was to determine whether there are any benefits or hazards of treatment detectable up to the seventh year of life The first 318 children of mothers included in the trial because of spontaneous premature labor were selected for study Of 305 survivors, 258 (846%) were included in this phase of the study Detailed tests of psychological development, together with assessments of psychosocial background, were made during the fifth year Of the 258 children 144 were in the betamethasone group and 114 were control patients Despite a heavy weighting of the betamethasone group with more prematurely delivered infants and more boys (resulting from improved perinatal survival of these children associated with betamethasone therapy), no significant differences emerged between the groups in measures of outcome It was concluded that betamethasone therapy, under the conditions of the original trial, was not hazardous to cognitive development as measured in this study
TL;DR: In this paper, a clinical methodology was used to investigate the perceptions which pupils of secondary school age have concerning modes of mathematical argument which have an agreed status within the world of mathematics.
Abstract: A clinical methodology was used to investigate the perceptions which pupils of secondary school age have concerning modes of mathematical argument which have an agreed status within the world of mathematics. The analysis of data obtained from three extended contexts led to the identification of clusters of characteristic response types. Differences were found to exist between the agreed meaning of some mathematical terms and procedures and the meaning ascribed to them by students. By considering levels of performance it was possible to identify particular components, the presence or absence of which consistently determined the capacity to structure or follow proofs and explanations.
TL;DR: HRP-labelled cells were identified in several regions of the brain stem including: trigeminal nuclei, vestibularuclei, nucleus coeruleus, tegmental field, deep layers of the superior colliculus, substantia nigra, dorsal median nucleus of Raphe and periaqueductal grey substance.
TL;DR: In this article, it is suggested that small-scale ionospheric structures (which are undoubtedly also present) are effective in inhibiting some of the specular reflections thus contributing to the diffuse nature of some records.
TL;DR: It is suggested that biting is a learned response spread by visual communication, so that visual barriers around affected groups may help to limit the spread of an outbreak.
Abstract: Groups of pigs were observed from weaning to marketing for the incidence of tail and/or ear biting and persistent inguinal nose thrusting. The 16 groups included single and mixed litters, single or mixed-sex ratios, and comprised up to 12 pigs; 14 of the groups showed biting behaviour and 12 groups showed persistent inguinal nose thrusting behaviour. The onset of biting appeared from 0 to 44 days after weaning, and persistent inguinal nose thrusting was first observed 4 to 22 days after weaning. There was a significant relationship between the number of pigs biting and being bitten in a group. The high ranks tend to bite middle and low ranks more than expected, the middle ranks bite other middle ranks more than expected, and low ranks bite the least. Within any rank there was no difference between male and females biting or being bitten. The most common situation was to have, in a group, some pigs which only tail bit, others that only ear bit, and others which both tail and ear bit. It is suggested that biting is a learned response spread by visual communication, so that visual barriers around affected groups may help to limit the spread of an outbreak. In persistent inguinal nose thrusting behaviour, rank was important, as the top ranking pigs were the most most likely to show persistent inguinal nose thrusting. Persistent inguinal nose thrusting may have its origin in udder seeking, exploratory or rooting behaviour, but becomes used mainly by dominant pigs. The behaviour is halted by the pig which received the nose thrusts moving away.