Showing papers by "University of Adelaide published in 1983"
TL;DR: A situation where an alteration in the final‐year assessment scheme led to changes in student learning activities which were the exact opposite of those intended is described.
Abstract: This paper describes a situation where an alteration in the final-year assessment scheme led to changes in student learning activities which were the exact opposite of those intended. Students were seen to be spending a disproportionate amount of time studying the theoretical components of the course relative to the practical and clinical aspects. The paramount importance of the assessments and examinations in influencing student learning behaviour led the departments concerned to develop a new clinical examination which more clearly reflected the objectives of the course. A questionnaire survey was undertaken to determine how the different sections of the final assessment affected the students' approach to studying. The questionnaire was administered to graduates during their intern year for the 3 years following the introduction of the new clinical examination. Results were also obtained for the year preceding the change. The survey showed that the students developed a high regard for the new examination and its validity as a test of clinical competence. The students found that an increase in ward-based learning activities was essential for success in the final examinations. The new clinical examination has thus influenced students' learning and successfully restored the balance of their learning activities between the clinical and theoretical components of the course.
501 citations
TL;DR: In this article, the vertical flux of horizontal momentum can be measured by ground-based radars using two or more radar beams each offset from the vertical to measure the atmospheric motions by the Doppler technique.
Abstract: Recent theoretical studies have emphasized the probable importance of internal gravity waves in balancing the momentum budget of the mesosphere. In this paper, we propose a method by which the vertical flux of horizontal momentum can be measured by ground based radars. The method uses two or more radar beams each offset from the vertical to measure the atmospheric motions by the Doppler technique. Provided there is horizontal homogeneity, the momentum flux is proportional to the difference of the variances of the Doppler velocities measured in each beam. The flux convergence and, hence, the associated body force acting on the atmosphere can be inferred by measuring the flux as a function of height. It is shown that mean wind components can also be measured by this method and, under certain circumstances, so can the horizontal wavelengths and phase velocities of the internal waves. Observations of the vertical flux of zonal momentum made with this technique using an HF radar located near Adelaide,...
367 citations
TL;DR: This review discusses the development of these cereal—ley systems with particular reference to the role of annual legume pastures, and points out their relevance to other regions with similar climatic patterns.
253 citations
TL;DR: The most commonly used nomenclature for transition-metal complexes containing terminal carbene (A) or carbyne (B) ligands has been given by as discussed by the authors.
Abstract: Publisher Summary The rapid development of the chemistry of transition-metal complexes containing terminal carbene (A) or carbyne (B) ligands has been followed more recently by much research centered on bridged methylene compounds (C). As often occurs in new and developing areas of chemistry, some confusion about the nomenclature of these complexes has arisen. Protonation or alkylation of several ethynyl–metal derivatives gives the corresponding vinylidene complexes in high yield. Several vinylidene complexes of the group VI metals have been obtained by heating σ–chlorovinyl derivatives with tertiary phosphines, phosphites, arsines, or stibines. Several complexes containing μ -C=CHR ligands have been obtained directly from 1-alkynes and two equivalents (or excess) of an appropriate precurso. A general route to complexes containing propadienylidene ligands is by loss of water or alcohols from suitable carbene or vinylidene precursors, or of oxo or alkoxy functions from ynolate anions. The majority of the chemistry of vinylidene and propadienylidene complexes is concerned with their synthesis and reactions. Vinylidene is one of the best π-acceptors known and is exceeded only by SO 2 and CS. The vinylidene ligand occupies an important place in the sequence of reactions linking a variety of well-known η 1 -carbon-bonded ligands. Metal cluster complexes containing vinylidene ligands have been considered as models of species present when olefins or alkynes are chemisorbed on metal surfaces.
252 citations
TL;DR: This chapter considers the biochemistry, physiology, and agronomy of trace elements in plants in so far as they may influence host–pathogen relationships and the principles that seem to emerge from a study of the micronutrient effects on susceptibility to disease.
Abstract: Publisher Summary This chapter considers the biochemistry, physiology, and agronomy of trace elements in plants in so far as they may influence host–pathogen relationships. Each of the micronutrients can be identified with specific biochemical pathways, so their effects on disease offer avenues for elucidating mechanisms of resistance in higher plants. Certain general principles may be demonstrated, but the complex nature of many interacting factors influencing plant health limits the extent to which simple patterns emerge. The quest for general principles is stimulated by the increasing prevalence of micronutrient deficiencies in modern agricultural systems, in which the use of the appropriate micronutrients may be seen as a form of biological control. In contrast to the largely structural, conformational, and osmotic roles of the macronutrients, the micronutrients act as catalysts, cofactors, and inhibitors. In these roles, supraoptimal concentrations are physiologically important. A number of trace elements, which are not recognized as essential to plants, strongly influence the host–pathogen balance. Criteria of essentiality are usually established in artificial conditions of laboratory and glasshouse. The chapter summarizes the principles which emerge from a study of macronutrient effects on incidence of disease in higher plants and the principles that seem to emerge from a study of the micronutrient effects on susceptibility to disease.
210 citations
206 citations
TL;DR: In this article, a parabolic equation governing the leading-order amplitude for a forward-scattered Stokes wave is derived using a multiple-scale perturbation method, and the connection between the linearized version and a previously derived approximation of the linear mild slope equation is investigated.
Abstract: A parabolic equation governing the leading-order amplitude for a forward-scattered Stokes wave is derived using a multiple-scale perturbation method, and the connection between the linearized version and a previously derived approximation of the linear mild slope equation is investigated. Two examples are studied numerically for the situation where linear refraction theory leads to caustics, and the nonlinear model is shown to predict the development of wave-jump conditions and significant reductions in amplitude in the vicinity of caustics.
193 citations
TL;DR: In this paper, the synthesis of over sixty known and new derivatives of Ru3(CO)12 and H4Ru4nLn by substitution reactions initiated by sodium diphenylketyl is described.
161 citations
TL;DR: It was concluded that the flagellum functions as the carrier of the moieties that promote adherence and enhances virulence by facilitating the initial colonization of the small bowel.
Abstract: The role of the flagellar structure in the in vitro adherence and in vivo colonization of Vibrio cholerae was studied by comparing the behavior of pairs of related motility variants. Although the presence of the flagellum seemed essential for in vitro attachment, the property of motility was neither necessary nor sufficient. Since it was possible to demonstrate independently both motility and binding capacities associated with this structure, it was concluded that the flagellum functions as the carrier of the moieties that promote adherence. Studies using the infant mouse cholera model unequivocally demonstrated the in vivo significance of a functional flagellum and suggested that this structure enhances virulence by facilitating the initial colonization of the small bowel.
160 citations
TL;DR: Recruitment of sessile marine invertebrates onto small panels at two subtidal sites in southern Australia varied considerably on all spatial and temporal scales, providing little support for the concept of generally “good” or “bad” years for a coastal region as a whole.
152 citations
TL;DR: It is suggested that cimetidine inhibits the tubular secretion of both procainamide and n-acetylprocainamide, and, if so, represents the first documented evidence for this type of drug interaction in man.
Abstract: The hypothesis that basic drugs can compete for active tubular secretion by the kidney was tested in six healthy volunteers by comparing the single dose pharmacokinetics of oral procainamide before and during a daily dose of cimetidine. The area under the procainamide plasma concentration-time curve was increased by cimetidine by an average of 35% from 27.0±0.3 µg/ml·h to 36.5±3.4 µg/ml·h. The elimination half-life increased from an harmonic mean of 2.92 to 3.68 h. The renal clearance of procainamide was reduced by cimetidine from 347±46 ml/min to 196±11 ml/min. All these results were statistically significant (p<0.016). The area under the plasma concentration-time curve for n-acetylprocainamide was increased by a mean of 25% by cimetidine due to a significant (p<0.016) reduction in renal clearance from 258±60 ml/min to 197±59 ml/min. The data suggests that cimetidine inhibits the tubular secretion of both procainamide and n-acetylprocainamide, and, if so, represents the first documented evidence for this type of drug interaction in man. The clinical implications from this study necessitate dosage adjustments of procainamide in patients being concomitantly treated with cimetidine. The interaction is pertinent not only for basic drugs that are cleared by the kidney, but also for metabolites of basic drugs and endogenous substances which require active transport into the lumen of the proximal tubule of the kidney for their elimination.
TL;DR: Cimetidine is the first histamine H2-receptor antagonist with wide clinical application and total plasma clearance decreases as a function of decreasing renal clearance, plasma half-life increases, and the duration of effective plasma concentrations increases as well.
Abstract: Cimetidine is the first histamine H2-receptor antagonist with wide clinical application. It is a weak base and a highly water-soluble compound which can be measured in biological fluids by a number of high-pressure liquid chromatographic methods. Following intravenous administration, the plasma concentration profile follows multicompartmental characteristics. The total systemic clearance is high (500 to 600 ml/min) and is mainly determined by renal clearance. The volume of distribution (Vd beta or Vdss) is of the order of 1 L/kg and this about equals bodyweight. Elimination half-life is approximately 2 hours. Following oral administration of cimetidine, 2 plasma concentration peaks are frequently observed, probably due to discontinuous absorption in the intestine. The absolute bioavailability in healthy subjects is about 60%. In patients with peptic ulcer disease, bioavailability is around 70%, but the variation is much greater than in healthy subjects. Absorption and clearance of cimetidine are linear after 200 and 800mg doses. Mean steady-state plasma concentrations on a standard 1000mg daily dose are 1.0 microgram/ml (range 0.64-1.64 micrograms/ml) and are reproducible after treatment periods of up to 2 years. When taken with food, the extent of absorption is unaltered, but a delay occurs and only 1 peak in the plasma concentration curve is apparent. Partial gastrectomy (Billroth I, II) causes an increase in systemic availability of cimetidine by an unclear mechanism. Distribution of cimetidine leads to extensive uptake into kidney, lung and muscle tissues. It distributes into the cerebrospinal fluid (CSF) at a ratio of 0.1 to 0.2 compared with plasma. The mean saliva to plasma ratio is 0.2 (range 0.1-0.55). Plasma protein binding is 20%, and there is no relevant effect of changes in binding on the pharmacokinetics of cimetidine. Uptake of cimetidine into red blood cells leads to concentrations equal to those in plasma. Between 50 and 80% of the dose administered intravenously is recovered in urine as unchanged cimetidine. This fraction is less after oral doses, but is independent of the amount of the dose. In ulcer patients, 40% is recovered unchanged in urine after oral administration. Biliary excretion of cimetidine accounts for only 2% of the dose.(ABSTRACT TRUNCATED AT 400 WORDS)
TL;DR: The experiments demonstrated that even with the lowered post-myxomatosis population densities, rabbit grazing pressure would significantly affect recruitment in arid zone Acacia populations in the South Australian arid zones.
Abstract: Three experiments are reported concerning the effect of rabbit grazing fOryctolagus cuniculus L.) upon the recruitment of Acacia seedlings to populations in the South Australian arid zone. In western myall woodland f Acacia papyrocaqsa Benth.) under prevailing rabbit and sheep densities, seedlings exposed to grazing by these two herbivores or to rabbits alone were severely pruned, whereas totally protected seedlings grew unchecked. Seedlings of four Acacia species; A. papyrocarpa, A. oswaldii (F. Muell.), A. kempeana (F. Muell.) and A. burkittii (F. Muell. ex Benth.) were transplanted into four 50 m X 50 m rabbit-proof enclosures. Six rabbits were introduced into each enclosure and within 24 h half of the total seedling population had been grazed. This was at a seedling dry weight ratio of 11150 000 of the total fodder on offer. In one of the enclosures no seedlings were eaten and there is evidence to suggest that a dense patch of grass had a buffering effect, reducing grazing pressure. Small shoots cut from old Acacia and transferred to the ground throughout 1000 ha of western myall woodland were grazed rapidly near rabbit warrens and progressively less rapidly with increased distance from warrens. The experiments demonstrated that even with the lowered post-myxomatosis population densities, rabbit grazing pressure would significantly affect recruitment in arid zone Acacia populations in the
TL;DR: In this paper, a wall-pressure fluctuation pattern associated with the burst-sweep cycle of events in the wall region is identified. But the phase relationship with velocity fluctuations close to the wall and the wall shear-stress fluctuations during the burst cycle has not been established.
Abstract: The wall-pressure fluctuations beneath a turbulent boundary layer have been conditionally sampled on a basis of the high-frequency activity of the pressure fluctuations themselves, the high-frequency activity of the streamwise velocity fluctuations in the vicinity of the wall, and the excursions in velocity in the vicinity of the wall. This has led to the identification of a characteristic wall-pressure fluctuation pattern which is associated with the burst–sweep cycle of events in the wall region. The pattern has the form of an overpressure over a streamwise extent of about 1·5−2·0δ * , with a region of underpressure and a pressure minimum to either side of it, the distance between pressure minima being about 3·0−3·5δ * . This pattern is convected at a velocity 0·67 times the freestream velocity. Its phase relationship with velocity fluctuations close to the wall and the wall shear-stress fluctuations during the burst–sweep cycle have been established. It appears to be produced by the inclined shear layer which forms the upstream surface of the large organized structures in the layer, and calculated pressure patterns support this conclusion. The phase relationships indicate that fluid involved in the bursting process is subjected to a favourable streamwise pressure gradient by the characteristic wall-pressure pattern at the time that the lift-up of low-speed streaks in the wall region begins. In addition, order-of-magnitude estimates suggest that the adverse pressure gradients associated with the characteristic pressure pattern, even if their phasing with streak lift-up were appropriate, would be insufficient to initiate the lift-up. It is therefore concluded that the streamwise pressure gradients associated with the pressure patterns do not play an active role in the dynamics of the wall flow and are not the direct cause of the bursting process.
TL;DR: It is considered that the yield potential of annual crop species increase at a faster rate than with empirical selection for yield if suitable ideotypes are identified.
Abstract: Publisher Summary This chapter considers that the yield potential of annual crop species increase at a faster rate than with empirical selection for yield if suitable ideotypes are identified. A considerable list of common features and practices that influence yield in all annual seed crops is identified, and it is possible to design a basic ideotype for all these crops, involving principles of crop physiology and associated agronomic practices equally applicable to any annual seed crop. A sharp distinction is drawn between the ecology of annual field crops grown for their seed and that of most horticultural crops. Horticultural plants are cultivated for their fruits, unripe seeds, roots, stems, or leaves. The chapter recognizes several categories within Darwin's general processes of selection by man and natural selection. These are discussed in relation to annual seed crops. It is evident that all crops have been subject to many similar selective and evolutionary processes during domestication. They have become adapted to both the natural environment of the region and the manmade environment of local cultural methods. Crop yield is a man-made concept. It does not necessarily relate to natural selection or to crop evolution, and it is expressed by the nonbiological criterion of weight of product per unit area. The harvest in some crops is a vegetative part whereas in others it is a reproductive organ.
TL;DR: Using 18O isotope shifts in 15N NMR it has been shown that during oxidation of nitrite to nitrate by Nitrobacter agilis, the third ‘O’ in nitrate originates from water.
TL;DR: Three selective media for the isolation of the three known biovars of Agrobacterium are described and recovery of agrobacteria from soil was very efficient and discrimination between the three biovARS was satisfactory except for tartrate-utilising biovar 1 isolates which grew on theBiovar 3 medium.
Abstract: Three selective media for the isolation of the three known biovars of Agrobacterium are described. Selectivity was based on carbon and nitrogen sources; L(—)-arabitol for biovar 1, erythritol for biovar 2 and a combination of tartrate and D-glutamate for biovar 3. The new media were compared with existing selective media. Recovery of agrobacteria from soil was very efficient and discrimination between the three biovars was satisfactory except for tartrate-utilising biovar 1 isolates which grew on the biovar 3 medium. Some strains of Pseudomonas sp. isolated from crown galls on vine could utilise octopine as a source of carbon and nitrogen.
TL;DR: In this paper, three groups of anions were distinguished in order of effectiveness with respect to the dispersion and flocculation of soil samples treated with Fe(III) polycations: phosphate and fulvate citrate, oxalate, silicate and tartrate and salicylate, catechol, aspartate, lactate and acetate.
TL;DR: In this article, the authors examined the relationship between IQ and measures of timed performance derived from inspection time and reaction time, and concluded that these measures do not, at this time, provide a basis from which a reliable culture-fair measure of intelligence might be devised.
TL;DR: Two genomic clones containing three B2 high-sulphur keratin genes from a sheep genomic library constructed in Charon 4A are isolated, finding a highly conserved 18 bp sequence which is also present in another gene coding for a member of a different, unrelated high-magnifying keratin family.
Abstract: We have isolated two genomic clones containing three B2 high-sulphur keratin genes from a sheep genomic library constructed in Charon 4A. These genes do not contain intervening sequences. Two genes, encoding the B2A and B2D proteins are closely linked in the genome, being separated by 1.9 kb, and are transcribed in the same direction. Although there is extensive sequence conservation in the 5' non-coding and coding regions, the 3' non-coding regions diverge both in length and sequence. Within the 5' non-coding region adjacent to the initiating AUG there is a highly conserved 18 bp sequence which is also present in another gene coding for a member of a different, unrelated high-sulphur keratin family. In the B2A-B2D intergene region, tightly linked to the B2D gene, there is a putative, divergently transcribed gene.
01 Jan 1983
TL;DR: In this paper, the authors provide some background information about the purposes of assessment and the basic principles of educational measurement and detail the forms of assessment with which you should be familiar in order that you can rationally select the best method to use.
Abstract: Being involved in student assessment is perhaps the most critical of all tasks facing the teacher. Generally, teachers take such involvement quite seriously but, sadly, the quality of many assessment and examination procedures leave much to be desired. The aim of this chapter, therefore, will be to help you to ensure that the assessments with which you are involved will measure what they are supposed to measure in as fair and as accurate a way as possible. We will provide some background information about the purposes of assessment and the basic principles of educational measurement. We will then detail the forms of assessment with which you should be familiar in order that you can rationally select the best method to use.
TL;DR: During a 2-d sequence of anthesis, the spadices of the thermogenic arum lily, Philodendron selloum, regulated maximum temperature within a small range by reversible thermal inhibition of respiratory heat production, indicating that there was no net phosphorylation during thermogenesis, heat production being the primary function of high rates of respiration.
Abstract: During a 2-d sequence of anthesis, the spadices of the thermogenic arum lily, Philoden- dron selloum, regulated maximum temperature within a small range (37-44 ~ C) by reversible thermal inhibition of respiratory heat production. This response protects the inflorescence and the attracted insects from thermal damage. Heat pro- duction by whole spadices, measured by O2 respir- ometry, equalled heat loss, measured by gradient layer calorimetry, which confirmed the heat equiv- alence of O2 consumption (20.4 J ml- 1). This also indicated that there was no net phosphorylation during thermogenesis, heat production being the primary function of high rates of respiration. The sterile male florets consumed about 30 ml g-1 h- 1 and the average 124-g spadix produced about 7 W to maintain a 30 ~ C difference between spadix and ambient temperature. Most of the energy for ther- mogenesis is present in the florets before anthesis. Despite high respiratory rates, thermogenesis is an energetically inexpensive component of the repro- ductive process.
TL;DR: The findings indicate that the LUF is a sporadic and infrequent phenomenon, an uncommon cause of infertile cycles in potentially fertile women and represents a biologic variable rather than a syndrome.
TL;DR: The pregnancy and multiple pregnancy rates after stimulation with clomiphene alone or with human menopausal gonadotropin were comparable, but oocyte pickup based on a knowledge of the duration of the endogenous rise in luteinising hormone, rather than 36 h after administration of human chorionic gonadotropic hormone, increased the pregnancy rate.
TL;DR: The Ediacara fossil assemblage occurs widely in the Flinders Ranges, South Australia, in a single, readily mappable stratigraphic interval as mentioned in this paper, which is part of the Pound Subgroup of the Wilpena Group.
Abstract: The Ediacara fossil assemblage occurs widely in the Flinders Ranges, South Australia, in a single, readily mappable stratigraphic interval—the Ediacara Member of the Rawnsley Quartzite, which is part of the Pound Subgroup of the Wilpena Group. The Member occurs low in the Rawnsley Quartzite and consists of siltstones, medium‐ to thick‐bedded sandstones, and heterolithic units of intercalated siltstone and sandstone. Features such as rhythmical bedding and flaser bedding, interference and flat‐topped ripples, winnowed coarse sand residues, abundant clay galls, and rare desiccation cracks suggest that the heterolithic siltstone/sandstone units represent intertidal deposits. The rich body‐fossil assemblage occurs chiefly in these deposits of probable intertidal origin, and for the most part appears to represent organisms stranded by the tide away from their normal habitat. Associated bioturbation structures include horizontal, penetrative (post‐depositional) burrows, but vertical dwelling burrows ha...
TL;DR: The distributions of three “forms”, actually sibling species, of meat ant were studied near Morgan, South Australia, an area with mean annual rainfall of 230 mm, and it was suggested that the numbers of individuals and species of other taxa active on the soil surface, predominantly Collembola, were affected by numbers of ants.
Abstract: The distributions of three “forms”, actually sibling species, of meat ant were studied near Morgan, South Australia, an area with mean annual rainfall of 230 mm. Colony dispersion is described for a “blue form” and for formpurpureus sens. strict. which occurs in this locality far beyond its normal low rainfall limit. An unusually large colony ofpurpureus had a territory covering 10 ha with more than 85 nests and over 1,500 individual nest entrances. Worker interactions between forms, and within and between colonies within forms are described.
TL;DR: Platelet aggregation was inhibited to an equal extent by all preparations and it is postulate that acetylation of cyclooxygenase in the portal circulation and that inhibition of peripheral cyclo oxygengenase may be spared.
Abstract: Our aims were (1) to determine the effect of six commercially available aspirin (ASA) preparations on in vitro platelet aggregation, and (2) to relate changes in platelet function to ASA kinetics. Each of six subjects took a single dose of one of the following preparations—600 mg Asproclear, 600 mg Bufferin, 600 mg Bi-prin, 600 mg compressed ASA, 650 mg Ecotrin, or 650 mg S.R.A.—in random order every 3 wk. Venous blood was drawn before and at 2, 4, 6, and 24 hr after ASA dosage to measure platelet aggregation in response to collagen and adenosine diphosphate and, at more frequent intervals, to characterize ASA kinetics. Asproclear, Bufferin, Bi-prin, and compressed ASA yielded peak plasma ASA levels of 28 to 56 pmolll (5 to 10 mg/l) within 15 to 60 min and peak salicylic acid (SA) levels of 72 to 290 µmol/l (10 to 40 mg/l) within 2 hr. Ecotrin and S.R.A. yielded plasma SA levels of 14 to 87 µmol/l (2-12 mg/l) within 4 to 24 hr and no measurable ASA at any time after dosing. Platelet aggregation was inhibited to an equal extent by all preparations. The time course for this inhibition was the same for all preparations but Ecotrin (which led to a more delayed effect). There was significant recovery of collagen-induced platelet aggregation at 24 hr with all preparations but Ecotrin. With Ecotrin and S.R.A. there was inhibition of platelet aggregation in the absence of measurable circulating ASA. We postulate that this was due to acetylation of cyclooxygenase in the portal circulation and that inhibition of peripheral cyclooxygenase may be spared.
Clinical Pharmacology and Therapeutics (1983) 33, 367–374; doi:10.1038/clpt.1983.47
TL;DR: It is concluded that the electrically stimulated efflux of [3H]‐GABA originated from GABAergic neurones of the myenteric plexus which had taken up the label and provided further evidence to support the suggestion that GABA is a transmitter in the mammalian enteric nervous system.
Abstract: 1--Following preloading with [3H]-gamma-aminobutyric acid ([3H]-GABA), in the presence of beta-alanine to inhibit glial uptake of the label, electrical stimulation caused a frequency-dependent release of tritium as [3H]-GABA from isolated longitudinal-muscle myenteric-plexus preparations of the guinea-pig ileum and colon. 2--The electrically evoked efflux of [3H]-GABA was Ca2+-dependent, virtually abolished by preventing neuronal conduction with tetrodotoxin, and markedly reduced by preloading with [3H]-GABA in the presence of nipecotic acid which is an inhibitor of high affinity GABA-uptake. Veratridine and KCl were less effective than electrical stimulation in evoking [3H]-GABA release. 3--It is concluded that the electrically stimulated efflux of [3H]-GABA originated from GABAergic neurones of the myenteric plexus which had taken up the label. 4--These results provide further evidence to support the suggestion that GABA is a transmitter in the mammalian enteric nervous system.
TL;DR: The Fyfe Hills of Enderby Land, Antarctica, are composed of Archaean cratonic rocks of the Napier Complex as discussed by the authors, and their initial crustal formation (possibly of plutonic, volcanic and sedimentary origin) was in the early Archaean, but probably significantly later than the 4000 Ma ages previously reported.