Showing papers by "University of Adelaide published in 1982"
TL;DR: In this article, the effectiveness of various binding agents at different stages in the structural organization of aggregates is described and forms the basis of a model which illustrates the architecture of an aggregate.
Abstract: Summary
The water-stability of aggregates in many soils is shown to depend on organic materials. The organic binding agents have been classified into (a) transient, mainly polysaccharides, (b), temporary, roots and fungal hyphae, and (c) persistent, resistant aromatic components associated with polyvalent metal cations, and strongly sorbed polymers. The effectiveness of various binding agents at different stages in the structural organization of aggregates is described and forms the basis of a model which illustrates the architecture of an aggregate. Roots and hyphae stabilize macro-aggregates, defined as > 250 μm diameter; consequently, macroaggregation is controlled by soil management (i.e. crop rotations), as management influences the growth of plant roots, and the oxidation of organic carbon. The water-stability of micro-aggregates depends on the persistent organic binding agents and appears to be a characteristic of the soil, independent of management.
5,389 citations
TL;DR: The female fertility of previously heat-stressed plants was assessed by pollinating with pollen from plants grown at a lower temperature and hand pollinated with similar pollen, indicating that female fertility was reduced by high temperature.
269 citations
TL;DR: In this paper, β-Rutinosides (6-O-α- l -rhamnopyranosyl-β- d -glucopyranoides) and 6-Oα-l -arabinofuranosylβ-d-glucopeysides of Geraniol, nerol and linalol have been isolated and characterized in Muscat of Alexandria grapes and wine.
244 citations
TL;DR: The feeding of melatonin had no apparent effect on the baseline serum levels of either FSH or LH, the frequency and amplitude of the LH peaks, or the changes evoked in serum PRL after the ...
Abstract: The effects of melatonin feeding on serum PRL and gonadotropin concentrations and on the reproductive activity of seasonally anestrous sheep were examined. Ten maiden Border Leicester X Merino ewes (18 months) were acclimatized to 16 h of light daily (from 0300–1900 h) for 4 weeks. Five of the animals were then fed pellets treated with melatonin (2 mg/ day); the remainder received untreated pellets daily at 1100 h for 103 days. Seventeen days after the commencement of treatment, serum PRL levels were found to be significantly lower between 1500–1900 h and 2400–0800 h (P < 0.05) in the melatonin- fed group compared to untreated animals. By day 31 and on all subsequent occasions tested up to day 99, serum PRL levels were lower (P < 0.01) in the melatonin-fed animals throughout the entire 8-h sampling period (0900–1700 h). The feeding of melatonin had no apparent effect on the baseline serum levels of either FSH or LH, the frequency and amplitude of the LH peaks, or the changes evoked in serum PRL after the ...
208 citations
TL;DR: In this paper, the steady flow of a fluid over a semicircular obstacle on the bottom of a stream is discussed, along with a numerical method for the solution of the fully nonlinear problem.
Abstract: The two-dimensional steady flow of a fluid over a semicircular obstacle on the bottom of a stream is discussed. A linearized theory is presented, along with a numerical method for the solution of the fully nonlinear problem. The nonlinear free-surface profile is obtained after solution of an integrodifferential equation coupled with the dynamic free-surface condition. The wave resistance of the semicircle is calculated from knowledge of the solution at the free surface.
181 citations
TL;DR: A contribution to knowledge of the unseen biological consequences which accompany that orthodontic treatment is presented as a contribution to the understanding of the periodontal ligament and its associated tissues which provide the basis for professional services.
Abstract: Apical root surfaces covered by cellular cementum are rapidly subjected to resorption under orthodontic loads of varying magnitude and duration. Within the experimental parameters employed, the intrusive forces applied to the teeth produced a striking increase in root resorption compared with the control teeth. The amount of resorption increased markedly with the duration of the force, and to a lesser extent with the magnitude of the appliance activation. After 70 days, cellular cementum repair accompanied the continuing resorption. Little variation was detected in the susceptibility of different patients to root resorption in the experimental teeth. The same intrusive load applied for the same duration to similar teeth produced a corresponding degree of root resorption in various individuals. On the other hand, there were individual differences in the amount of resorption on untreated control teeth. There is a need to extent our understanding of the periodontal ligament and its associated tissues which provide the basis for our professional services. Clearly, root resorption and the capacity for repair are orthodontic facts of life. In the current climate of technological innovation great emphasis has been given to cephalometrics and appliance mechanics, which provide the orthodontist with the clinical stimulus of visual and tactile involvement. This paper is presented as a contribution to our knowledge of the unseen biological consequences which accompany that orthodontic treatment.
174 citations
TL;DR: Combined antagonism of GABAA-receptors and desensitization to baclofen slowed pellet expulsion to the same extent as GABA desens itization alone, indicating that both GAB AA- and GABAB-receptor sites are involved in this modification of peristalsis by GABA.
172 citations
TL;DR: Glycosidic derivatives of monoterpene flavourants of grapes and wines can be preparatively isolated by selective retention on a C 18 -bonded reversed-phase adsorbent.
160 citations
TL;DR: In human teeth, periodontal attachment to resorbed and repairing surfaces was shown to be present andperiodontal fibers and fiber bundles inserted directly into the repair cellular cementum matrix, irrespective of the site of the lesion on the root.
144 citations
TL;DR: In this paper, the authors found that the greatest proportions of water stable aggregates arose from wetting and drying in the - 1 to - 100 kPa range of matric water potential.
Abstract: Summary Wetting and drying of remoulded soil resulted in water stable aggregation. The greatest proportions of water stable aggregates arose from wetting and drying in the - 1 to - 100 kPa range of matric water potential. The effect occurred with sterile and non-sterile soil. but the proportion ofwater stable aggregates was less with sterile soil. The application of wetting and drying cycles in the laboratory to non-tilled soil resulted in a steady decrease in the proportion of water stable aggregates. With tilled soil, the proportion of water stable aggregates first increased to a maximum and then decreased steadily with further wetting and drying cycles. However. with sterilized, tilled soil, only a steady decrease in the proportion of water stable aggregates was observed. Natural water content fluctuations in the field after tillage gave an increase in water stability to a maximum after a few days followed by a steady decrease. The similarity of this result to that obtained in the laboratory for tilled. non-sterilized soil indicates that micro-organisms were probably contributing to the observed shortterm changes in the water stability ofaggregates in the field.
139 citations
TL;DR: Erythrocytes were shown to be important for separation of leucocytes into two distinct bands and increasing the height of the blood column by diluting the blood in medium 199 did not increase the separation distance.
TL;DR: The Ediacarian, here defined as the initial period and system of the Phanerozoic Eon, is characterized by the oldest known multicellular animal life, represented in the type region by 26 species in 18 genera and 4 or more phyla, plus simple metazoan surface tracks.
Abstract: The Ediacarian, here defined as the initial period and system of the Phanerozoic Eon, is characterized by the oldest known multicellular animal life. The distinctive biotal assemblage comprises naked Metazoa, represented in the type region by 26 species in 18 genera and 4 or more phyla, plus simple metazoan surface tracks. Elements of this unique biota appeared worldwide at low paleolatitudes, following terminal Proterozoic glaciation. Ediacarian history lasted from about 670 million to 550 million years ago. This interval, plus Early Cambrian, was the time during which metazoan life diversified into nearly all of the major phyla and most of the invertebrate classes and orders subsequently known.
TL;DR: Three approaches to a theoretical analysis of confidence judgments are considered: one linking confidence to the number of sensory observations, one based on a distinction between ‘state’ and ‘process’ factors, and a ‘balance of evidence’ hypothesis developed from an accumulator model of discrimination.
TL;DR: Variant ccRNAs found in nine isolates sequenced may have arisen as by-products or intermediates of viroid replication in Cadang-cadang.
Abstract: Cadang-cadang is a serious lethal disease of coconut palms in the Philippines. Infectivity is associated with four viroid RNAs (ccRNAs) which are from 246 to 574 residues in size but do not vary in sequence complexity. They share sequence and structural homology with other viroids. Variant ccRNAs found in nine isolates sequenced may have arisen as by-products or intermediates of viroid replication.
TL;DR: In this article, it was shown that the Miocene Macquarie Island ophiolite, south of New Zealand, has oxygen and carbon isotopic compositions comparable to those of seafloor rocks.
TL;DR: A double‐blind controlled cross‐over study of amitriptyline vs. placebo was carried out in a group of patients referred to a multidisciplinary pain clinic for the management of chronic intractable pain for which no substantial organic cause could be demonstrated.
Abstract: This paper reports a study in which a double-blind controlled cross-over study of amitriptyline vs placebo was carried out in a group of patients referred to a multidisciplinary pain clinic for the management of chronic intractable pain for which no substantial organic cause could be demonstrated Of 52 patients entering the 12-week trial, 20 withdrew before completion No differences were found in terms of global improvement on either agent Subjective reports indicated a greater reduction in pain at 2 and 4 weeks on amitriptyline, but no difference at 6 weeks None of the baseline measures was predictive of response
TL;DR: The application of abscisic acid solution to developing spikes of wheat via wicks threaded through peduncles at the stage of meiosis in pollen mother cells caused pollen sterility without affecting female fertility.
Abstract: The application of abscisic acid solution to developing spikes of wheat (cv. Gabo) via wicks threaded through peduncles at the stage of meiosis in pollen mother cells caused pollen sterility without affecting female fertility. The concentration of abscisic acid measured in the spikelets of plants treated in this manner was close to that induced by water stress, which produced a similar level of pollen sterility. After pollen mother cell meiosis, treatment with abscisic acid had no effect on pollen fertility, as has been shown previously with water stress. Abscisic acid applied immediately before meiosis reduced fertility, in contrast to the effect of water stress, but this may have been due to persistence of the hormone in the plant. High temperature during pollen mother cell meiosis had no effect on the endogenous abscisic acid content of the spikelets, even where the treatment caused a complete inhibition of grain set.
TL;DR: The pairing of the sex chromosomes at pachytene has been examined in twenty-two species of Australian marsupials, including four with complex sex chromosome systems.
Abstract: The pairing of the sex chromosomes at pachytene has been examined in twenty-two species of Australian marsupials, including four with complex sex chromosome systems. The axial elements of the sex chromosomes associate in all but one species. However, no synaptonemal complex has been observed between the axes of the X and Y chromosome in any of the examined species. Both the type of association between the sex chromosome axes, and the structural modifications of these axes are conserved within taxonomic groupings. In three species with complex sex chromosome systems, the t(XA), Y, A trivalents do not have a favoured relative orientation of the axes of the Y and A chromosomes, whereas in a fourth species with a t(XA1), t(A2YA1), A2 system the t(XA1) and A2 axes are in a cis arrangement with each other.
TL;DR: The target antigens of a series of monoclonal antibodies raised against a complex mixture of proteins have been identified by incubating nitrocellulose strips with the 'hybridoma' culture supernatants and detecting bound antibody using alkaline phosphatase conjugated to rabbit anti-mouse F(ab')2 antibody, and histochemical substrates.
TL;DR: Rapid growth of roots at high levels of Na2HPO4 resulted in reductions in percentage root length infected by mycorrhizas, and high rates of uptake were associated with reductions in root: shoot dry wt ratios.
Abstract: Summary
During early growth of mycorrhizal and non-mycorrhizal plants of Trifolium subterraneum fertilized with soluble (Na2HPO4) phosphate, inflow of phosphate (moles P absorbed per unit length root per unit time) into mycorrhizal roots from soil exceeded that into non-mycorrhizal roots over a range of levels of phosphate. High rates of uptake (up to 45 × 10−15 mol phosphate cm−1 s−1) were associated with reductions in root: shoot dry wt ratios.
The length of mycorrhizal root per plant was little affected by fertilization with phosphate. However, rapid growth of roots at high levels of Na2HPO4 resulted in reductions in percentage root length infected by mycorrhizas. Results are discussed with respect to rates of uptake by whole plants and to differences in distribution of phosphate between roots and shoots in mycorrhizal and non-mycorrhizal plants.
TL;DR: Evidence from the performance of nonretarded subjects in three studies suggests that although speed of decision is related to IQ, the degree of association is smaller than recent publicity has suggested.
Abstract: Recent publicity has been given to reports of high correlations between IQ and “inspection time”, a measure derived from simple discrimination which is assumed to provide an estimate of the time taken by a basic component of the decision process. However, this publicity has not recognised that the inclusion of mentally retarded participants in the experiments concerned may have led to inflated correlations, because of the marked extent to which the performance of retarded subjects is inferior to that of nonretarded subjects. Evidence from the performance of nonretarded subjects in three studies suggests that although speed of decision is related to IQ, the degree of association is smaller than recent publicity has suggested. Inspection time does not appear at present to hold promise as an index from which a “culture-fair” measure of intelligence might be derived.
TL;DR: In this paper, a full X-ray crystallographic analysis of Ru3(CO)10(η-dppe) was performed using 3558 data with I ⩾ 2.5 σI.
TL;DR: The application of stable isotope labelled drugs in clinical pharmacokinetic studies has rapidly increased over the past decade and the major advantages are that time-dependent variations in drug disposition are minimised; a small number of subjects are required in bioavailability studies; and patients are less inconvenienced.
Abstract: The application of stable isotope labelled drugs in clinical pharmacokinetic studies has rapidly increased over the past decade. Isotopes are atoms of the same chemical element, but differ from one another by their mass, due to the different number of neutrons in the nucleus. As they are not radioactive they can be administered in therapeutic doses to man. The major applications of stable isotope labelled drugs are as an internal standard in gas chromatography-mass spectrometry (GC-MS) analysis and as so-called ‘biological internal standards’. This latter application is accomplished by administering the stable isotope labelled drug to man, measuring its plasma concentration and determining various pharmacokinetic parameters. Problems associated with this technique include having a suitable mass difference between labelled and unlabelled drug, having the label in the fragment ion to be monitored and exclusion of isotope effects. The applications of the technique include investigations into the pharmacokinetics and autoinduction of carbamazepine metabolism in epileptic patients during long term monotherapy and combination therapy, and determination of the time course of carbamazepine disposition in children, studies of valproic acid pharmacokinetics during combined anticonvulsant therapy and during pregnancy, and the influence of valproic acid on phenobar-bitone (phenobarbital) disposition. These studies have been conducted in patients by substituting the normal dose with a pulse dose of the labelled antiepileptic drug and hence normal therapy was continued and not withdrawn. Also, several studies have been conducted with a solution of stable labelled verapamil, including single dose and multiple dose pharmacokinetics, and disposition and bioavailability in liver cirrhosis and in a patient before and after construction of a mesocaval shunt. Aspects of drug metabolism have also been studied by the use of stable isotopes. These include the metabolism of procainamide and N-acetylprocainamide. Stereoselectivity of drug metabolism has been investigated using a pseudoracemate of warfarin, and the interaction of the enantiomers of warfarin with phenylbutazone and with quinalbarbitone (secobarbital) has elegantly demonstrated this stereoselectivity of human drug metabolism. Absolute bioavailability studies with N-acetylprocainamide, barbitone and verapamil have been performed with stable isotopes in that both the intravenous and oral doses were given simultaneously to man. The advantage of this technique has been clearly demonstrated in a study on the relative bioavailability of 2 different Imipramine formulations, in which it was shown that to detect a 20% difference in area under the plasma concentration-time curve (with a probability of 0.8) between the 2 formulations required the use of 20 subjects, but only 3 to 4 subjects with the stable isotope method. Other studies on the relative bioavailability of different formulations have been conducted with maprotiline, verapamil and timolol. The influence of formulation factors on the absorption of benoxaprofen, dextropropoxyphene and methoxsalen have been conducted by using solutions of their stable isotopes. The major advantages of using stable isotope labelled drugs are: (a) that time-dependent (i.e. day-to-day) variations in drug disposition are minimised; (b) a small number of subjects are required in bioavailability studies; and (c) patients are less inconvenienced, for studies which normally require dosing on 2 occasions can now be easily accomplished on the 1 occasion.
TL;DR: There is no negative feedback of melatonin upon its own synthesis and release, that there is no circadian change in the rate of metabolism ofmelatonin and that constant melatonin availability in sheep caused a depression in plasma prolactin levels similar to that found following exposure of animals to a short day.
Abstract: The effects of implanting Silastic capsules containing melatonin on plasma melatonin and prolactin levels were investigated in pinealectomized (Ptimes;) and sham-operated sheep (SPtimes;) Prior to implanatation, melatonin was found in plasma samples obtained during the night period from SPtimes; sheep (mean value 150 pg/ml), but could not be (<25 pg/ml) detected in plasma samples obtained during the day in SPtimes; sheep or in any sample obtained during the night or day period in Ptimes; sheep Following implantation, a constant basal plasma melatonin level of about 165 pg/ml was established in all sheep with a superimposed nighttime rise in SPtimes; animals suggesting no diminution of endogenous melatonin production during the dark period Following melatonin treatment, there was a marked depression in plasma prolactin levels in both SPtimes; and P× sheep These results are interpreted to indicate that 1) there is no negative feedback of melatonin upon its own synthesis and release, 2) that there is no
TL;DR: Analysis of plasmid-coded proteins in a minicell system showed that: (1) the products of phoB and phoR are proteins with apparent molecular weights of 30,000 and 47,000, respectively; and (2) the synthesis of thephoB gene product is derepressed byphoR mutations.
TL;DR: In this article, the root buckling stress was measured for seven plant species, including seminal and primary lateral roots, and the results showed that buckling stresses are not significantly affected by the concentration of nitrate in the growth medium.
Abstract: The mechanical stresses required to buckle root tips were measured directly for seven plant species. For two of these, both seminal and primary lateral roots were measured. For four of the plant species investigated, the easier and more rapid method used to measure the buckling stresses of excised root tips gave results which agree closely with those obtained for the growing roots of intact plants. Values of buckling stress were also calculated from previously determined elastic properties of roots. The calculated and measured values of buckling stress are of the same magnitude only, and comparison for ten root types fails to show any consistent relationship between these two methods. From the results from three plant species it has been possible to define empirical functions to account for the observed changes in root buckling stress with air gap length and water stress. Buckling stresses are not significantly affected by the concentration of nitrate in the growth medium.
TL;DR: The sequence and proposed secondary structure of the 371 residues of an Australian isolate of CEV are reported and the significance of the extensive sequence homology which exists between PSTV, CSV and CEV is discussed.
TL;DR: Laterality assessments for 1,966 unselected psychology undergraduates are compared on three questionnaires of tested reliability as discussed by the authors, and performances of the right and left hands of 167 university students are compared.
Abstract: Laterality assessments for 1,966 unselected psychology undergraduates are compared on three questionnaires of tested reliability. Performances of the right and left hands of 167 university students...
TL;DR: The topographic findings suggest that strong relapse forces are probably dissipated after 3 months of retention, and the proportion of repair tissue in the defects became greater with the more prolonged retention periods.