Showing papers by "University of Western Australia published in 1985"
376 citations
TL;DR: A significant reduction in the fertilization rate of mature oocytes was observed in those patients whose basal serum LH values were >1 SD above the mean, which may be a reflection of premature oocyte maturation or ageing.
367 citations
TL;DR: There exists in the motion system mechanisms selective for spatial frequency and orientation selectivity and there exist two classes of temporally tuned detectors of preferred temporal frequency of 7-13 Hz (depending on spatial frequency).
283 citations
TL;DR: The most likely natural product precursors for the tetracyclic diterpene hydrocarbons are considered to be the TPDP-derived diterpanes which occur widely in the leaf resins of conifers.
257 citations
TL;DR: A permanent cell line arising from a cerebellar medulloblastoma was established and its growth characteristics were investigated, and the primary tumor showed evidence of both glial and neuronal differentiation, and retention of neuronal differentiation occurred in both the cultured neoplastic cells and the nude mouse tumors.
Abstract: A permanent cell line arising from a cerebellar medulloblastoma was established and its growth characteristics were investigated. Although the original tumor inoculum failed to take, the cultured cells were readily tumorigenic in nude mice and gave rise to rapidly growing tumors which could be easily subpassaged. The primary tumor showed evidence of both glial and neuronal differentiation, and retention of neuronal differentiation, albeit minimal, occurred in both the cultured neoplastic cells and the nude mouse tumors. Glial differentiation, on the other hand, could not be demonstrated. G-banding analysis of the chromosomes present in the cell line showed that they were exclusively human.
220 citations
TL;DR: Efferent neurones within the intraganglionic spiral bundle of the guinea pig cochlea were characterized in terms of their response properties, and their pattern of termination within the receptor organ revealed by intracellular labelling with horseradish peroxidase.
189 citations
TL;DR: Differences among isolates of VA mycorrhizal fungi in the distribution of hyphae in soil may be as important as differences in the length of external hyPHae when selecting fungi that are effective at increasing nutrient uptake.
Abstract: Summary
The ability of several species of vesicular–arbuscular (VA) mycorrhizal fungi to form hyphae in soil was compared in two glasshouse experiments. We measured the length of hyphae in soil and related this to the length of infected root. Species of VA mycorrhizal fungi differed in the length of external hyphae produced per cm of infected root. Glomus fasciculatum (Thaxter sensu Gerd.) Gerd. and Trappe produced less external hyphae per cm infected root than did Gigaspora calospora (Nicol. and Gerd.) Gerd. at all harvest times and when inoculum was either placed in a band below the seed or mixed throughout the soil. Glomus tenue (Greenall) Hall and Acaulospora laevis Gerd. and Trappe both produced similar lengths of external hyphae per cm infected root to that formed by G. calospora.
Differences among isolates of VA mycorrhizal fungi in the distribution of hyphae in soil may be as important as differences in the length of external hyphae when selecting fungi that are effective at increasing nutrient uptake.
182 citations
TL;DR: In this paper, aqueous electrochemistry of a number of quinones and two hydroxyquinones was studied using cyclic voltammetry, and the results obtained for the potentialpH diagram agreed very closely with equilibrium measurements which had been reported in the literature for the same system.
180 citations
TL;DR: The prevalence of asthma among adults but not children living in eight South Fore villages of the Eastern Highlands of Papua New Guinea has risen dramatically over the past decade and now is 6 per 1000 in the age group less than 20 years and 73 per 1000 for adults living more than 20 decades as discussed by the authors.
Abstract: The prevalence of asthma among adults but not children living in eight South Fore villages of the Eastern Highlands of Papua New Guinea has risen dramatically over the past decade and now is 6 per 1000 in the age group less than 20 yr and 73 per 1000 in the age group more than 20 yr. Allergy to house dust mites appears to be a significant feature in the disease pathogenesis, and it is likely that this is associated with modifications to traditional lifestyles by the recent introduction of blankets and changes in sleeping habits that promote a more fertile environment for growth and multiplication of mites. Asthma is now provoked by a wide range of factors such as exertion, stress, and antecedent respiratory tract infections, which have always been common features of the South Fore way of life. This suggests that allergic reactivity may be the precursor of bronchial hyperreactivity that, once manifested, can be triggered by a variety of stimuli, not all of which are immunologic in origin.
173 citations
TL;DR: The injection of artificial classical Konishi perilymph with KA confirmed the strong difference between afferents innervating the IHCs and the OHCs in adult cochleas and shed some light on the synaptic plasticity found at the O HC level during synaptogenesis.
171 citations
TL;DR: In this article, the effect of time on phosphate sorption was examined by plotting the sorption data according to different, simple, kinetic equations such as the first order, second order, the parabolic diffusion equation, the Elovich equation and the modified Freundlich equation.
Abstract: SUMMARY
Iron and aluminium hydroxides were precipitated both in the presence and absence of kaolinite. The reaction between phosphate and these hydroxides was measured for periods which ranged from 5 min to 72 h. The effect of time on phosphate sorption was examined by plotting the sorption data according to different, simple, kinetic equations such as the first order, second order, the parabolic diffusion equation, the Elovich equation and the modified Freundlich equation. The effect of time on sorption was also examined by the mechanistic model recently developed by Barrow (1983b) for the sorption and desorption of phosphate by soils.
The sorption of phosphate by iron and aluminium hydroxides increased with time and the reaction continued through the period of observation without reaching a true equilibrium. Curvilinear relationships were obtained when the data were plotted according to the simple kinetic equations. These simple kinetic equations fail to describe the effect of time on sorption partly because the mechanism is different from that postulated and partly because they do not consider electrostatic effects when phosphate ions react with a charged surface. The mechanistic model of Barrow (1983b), which takes this effect into account, described effect of both concentration and time on phosphate sorption. According to this model, the increase in phosphate sorption with time was caused by a redistribution of adsorbed phosphate into the interior of the particles of iron and aluminium hydroxides by solid-state diffusion.
TL;DR: In this paper, the response of a rectangular, n-layered, stratified lake to an arbitrarily varying (in time) wind stress was considered in detail for the case n = 3 and the response was made up of the individual responses of one external and two internal modes.
Abstract: The solution for the response of a rectangular, n-layered, stratified lake to an arbitrarily varying (in time) wind stress is presented. The case n = 3 is considered in detail. For a three-layered lake the response is made up of the individual responses of one external and two internal modes. When the upper layer is shallow relative to the other two layers, the mixed-layer shear is due almost entirely to the slower, second-mode response. Moreover, the upper interface can tilt quite severely while the lower interface remains nearly flat. Calculations based on the three-layer model are compared with measurements made in Wellington Reservoir, Western Australia.
TL;DR: While the incidence of disc degeneration does increase in old age, the majority of the discs examined did not show evidence of any such change and add information to previous studies which indicate that the loss of transverse trabeculae of lumbar vertebrae is primarily responsible for the change in shape of both vertebraes and discs in the elderly.
Abstract: Measurements of disc thickness, shape and degeneration, using the criteria described by Rolander (1966), were recorded from 204 post-mortem lumbar spines. The "true average disc height" increased with age as the discs "sink" into the vertebrae. These results add information to previous studies which indicate that the loss of transverse trabeculae of lumbar vertebrae is primarily responsible for the change in shape of both vertebrae and discs in the elderly. While the incidence of disc degeneration does increase in old age, the majority of the discs examined did not show evidence of any such change.
TL;DR: In this article, a submarine groundwater discharge into a coastal lagoon off Perth, Western Australia, contains nitrate and silicate in concentrations two orders of magnitude higher than those of the receiving waters.
Abstract: Submarine groundwater discharge (SGD) into a coastal lagoon off Perth, Western Australia, contains nitrate and silicate in concentrations two orders of magnitude higher than those of the receiving waters. This discharge delivers enough nitrate to replace that dissolved in the lagoon water mass about every eight days and enough silicate to replace the lagoon silicate in about 48 days. The delivery rate of nitrate nitrogen by SGD is equal to about 48% of that required for observed growth rates of lagoon macrophytes. Surface salinity is lower close to the shore as a result of SGD. During calm conditions a salinity front was observed in the lagoon, with a nearshore pool of nutrient-enriched water floating above the more saline ocean water.
TL;DR: By using structural, kinetic and irradiation techniques it is possible to show that mesothelial healing is a local event and that early colonization by macrophages results in the removal of debris and probably prevents the formation of adhesions during Mesothelial restoration.
Abstract: By using structural, kinetic and irradiation techniques it is possible to show that mesothelial healing is a local event. Initially, macrophages occupy the surface of a wound on the injured visceral layer, while mesothelial proliferation proceeds at the edge of the wound and the opposing parietal surface. Fibrin is formed on the wound surface within 24 h, even in the absence of much haemorrhage. Mesothelial ingrowth begins with isolated cells migrating from the wound edge as well as from the serosal surface apposing the wound where mesothelial cells are actively replicating. The cells presumably slide over a bridge of fibrin and macrophages, a process likely to be enhanced by the serosal fluid. Early colonization by macrophages results in the removal of debris and probably prevents the formation of adhesions during mesothelial restoration.
TL;DR: The results support the idea that perceptual memory is distinguishable from recognition memory, and that it is developmentally stable.
Abstract: In this paper, we report four experiments aimed at extending the distinction between recognition memory and perceptual memory introduced by Jacoby and Dallas (1981). In Experiment 1, we show that dissociation of the two types of memory can be demonstrated with pictures as stimuli and with naming latency and recognition scores as responses. The depth-of-processing manipulation affects recognition but not naming, whereas both are influenced by prior exposure. Experiment 2 is a replication of the naming procedure, with a smaller set of stimuli and instructions emphasizing speed. Experiments 3 and 4 extend the paradigm to include children from 5 to 10 years old. Experiment 3 demonstrates the usual effect of depth of processing on recognition, but, in contrast to the adult data of Experiment 1, there is an analogous effect upon subsequent naming latencies. Examination of the data suggests this may be a spurious result. If not, it means either that the two memory types are not independent in children or that the “deep” subjects were implicitly naming during encoding. In Experiment 4, we test perceptual memory directly, replacing naming latency with tachistoscopic recognition. This results only in an effect of prior exposure, and not depth of processing. The results support the idea that perceptual memory is distinguishable from recognition memory, and that it is developmentally stable.
TL;DR: It was concluded that some aspects of the distribution of these efferent neurones in the guinea pig are similar to the situation in the rat, whilst others resemble more closely the arrangement found in cat.
TL;DR: Net flow of the various ions between shoot and root showed substantial return of K(+) and Mg(++) from shoot to root with phloem translocate, and rates of return flow to roots and circulation within the plant were very small for Ca(++) and for Na(+) under the conditions of the experiment.
TL;DR: In this article, the authors reported an incidence more than three times greater (5 tubal ectopic pregnancies in 80 clinical in vitro fertilization pregnancies) than the overall risk of around 2% ectopic pregnancy.
TL;DR: Guinea pig auditory ganglion cell responses to 100-ms duration tone bursts were recorded over a range of stimulus intensities and responses, recorded in the form of peristimulus/poststimulus time histograms, were analysed by reduction into two phases.
TL;DR: Three different porous ceramics—calcium aluminate, calcium hydroxyapatite, and tricalcium phosphate—were implanted into the proximal tibia in rats and rabbits to study the interactions between these Ceramics and a bony site that is abundant in bone marrow.
TL;DR: In this article, a method to match the response of the SBE-3 temperature sensor and conductivity cell is described, which uses a recursive filter in the time domain, which allows direct calculation of salinity and density.
Abstract: A method to match the response of the SBE-3 temperature sensor and the SBE-4 conductivity cell is described. The technique uses a recursive filter in the time domain, which allows direct calculation of salinity and density, and thus offers a significant computational advantage over other methods. The response of any sensor may be matched or sharpened using this method provided that the sensor can be modeled appropriately. Using this method the useful bandwidth of the SBE-3 temperature sensor may be improved by a factor of between 3 and 7, depending on the permissible signal-to-noise ratio degradation. It is also possible to match the SBE-3 and SBE-4 responses closely and thus remove spikes in the profiles of calculated salinity and density.
TL;DR: The parathymic and posterior mediastinal nodes draining the lower lung, are revealed, as the major sites of specific IgE and IgG production; smaller numbers of OVA-specific IgG-secreting cells (but none secreting Specific IgE) were detected in the node draining the upper respiratory tract, while antibody secretion outside the respiratory tract was restricted to comparatively few cells in the spleen.
TL;DR: The cubane structure of cubane cubane has been shown to have a tetrametallic structure rather than the expected "step" structure by single-crystal X-ray diffraction analysis as discussed by the authors.
Abstract: Recrystallization of [Cu4l4(PPh3)4] from toluene has yielded a new polymorph of that compound, (1), which has been shown by single-crystal X-ray diffraction analysis to have a tetrametallic ‘cubane’ structure rather than the expected ‘step’ structure. Crystals are monoclinic, space group P21/n, with a= 19.47(1), b= 26.94(1), c= 13.528(5)A, β= 98.98(4)°, Z= 4 tetramers; R was 0.06 for No= 3 681. Cu–I distances range from 2.653(3) to 2.732(3)A, with Cu ⋯ Cu 2.874(5)–3.164(4) and I ⋯ I 4.234(2)–4.496(3)A. All adducts of stoicheiometry [M4X4(PPh3)4](M = Cu or Ag; X = Cl, Br, or I) have now been synthesized and structurally characterized in a cubane configuration. Recrystallization of copper(I) chloride and bromide from triethylamine also yields tetrameric cubane 1 : 1 adducts [X = Cl (2) or Br (3)], as does the reaction of copper(I) chloride with the very bulky ligand 2-[bis(trimethylsilyl)methyl]pyridine, to give [Cu4Cl4(tmspy)4](4). These three complexes have also been crystallographically characterized, (2) and (4) being the first reported cubane type tetramers for the copper(I) chloride–nitrogen base system. Complexes (2) and (3) are isostructural with their triethylarsine and -phosphine counterparts, being cubic, space group I3m, with a= 12.162(5)A in (2) and 12.368(3)A in (3); Z= 2 tetramers. Cu–Cl,Br distances are 2.441(4) and 2.537(3)A respectively. For (4), the crystals are tetragonal, space group I41/a, with a= 18.620(4), c= 20.079(5)A, Z= 4 tetramers. Although the Cu4Cl4 cubane core of the molecule has crystallographically imposed symmetry, the geometry is very unsymmetrical as a consequence of the ligand bulk, with Cu–Cl 2.225(2)–2.636(2), Cu ⋯ Cu 2.960(2)–3.194(2), and Cl ⋯ Cl 3.838(3)–3.866(3)A. Residuals R for (2), (3), (4) were 0.040, 0.038, and 0.040 respectively for No= 136, 136, and 1 008 ‘observed’ reflections. The solid-state 31P n.m.r. spectra of the triphenylphosphine cubane clusters show significant differences to those with a ‘step’ geometry; these differences are related to the crystallographic environment of the phosphorus nuclei.
TL;DR: In this paper, it is observed that the temperature gradients and their seasonal occurrence are more predominant in the Southern Hemisphere than those in other parts of the world and the same mechanisms may be expected to be active in lakes of similar size and shape.
Abstract: The principles of physical limnology in the Southern Hemisphere are no different to those in other parts of the world and the same mechanisms may be expected to be active in lakes of similar size and shape. However, in actuality, it is observed (Imberger, 1982; Ward, 1982; Allanson & Jackson, 1983; Powell et al., 1984) that the temperature gradients and their seasonal occurrence are more predominant in the Southern Hemisphere. The temperature range is fixed by the winter cold inflow and the summer heating and the temperature range from the bottom of a lake to the lake surface in the Southern Hemisphere is commonly up to 10 C° or even 15 C° during the summer peak period. Combined with the overall elevated mean temperature, this leads to an extremely strong buoyancy stabilization of the water column and it is this which characterizes lakes in the Southern Hemisphere.
TL;DR: A method of estimating above-ground productivity in situ of the seagrass Amphibolis antarctica (Labill.) Sonder & Aschers. has been devised, using tags to determine rates of leaf turnover as discussed by the authors.
TL;DR: There is increasing recognition of immunological and pathological differences in polymyositis and juvenile and adult dermatomyositis, and in cases with associated connective tissue diseases, suggesting different underlying pathogenetic mechanisms.
Abstract: The inflammatory myopathies have diverse clinical and pathological features and multiple etiologies. Some are confined to a single muscel or group of muscles (e.g., orbital myositis and localized nodular myositis) while others are diffuse. Infective forms may be due to viral, bacterial, fungal, protozoal, or parasitic organisms. Viruses may cause acute self-limited forms of myositis and have been isolated from muscle in some cases of acute rhabdomyolysis and inclusion body myositis. They have also been implicated in some cases of acute rhabdomyolysis and inclusion body myositis. They have also been implicated in some cases of congenital myopathy and in polymyositis and dermatomyositis, but there is no evidence of viral invasion of muscle in these conditions. In polymyositis and dermatomyositis there are derangements in humoral and cellular immune function, and recent evidence suggests an underlying disturbance of immunoregulation. The roles of genetic factors, drugs, and Toxoplasma infection have been under scrutiny. There is increasing recognition of immunological and pathological differences in polymyositis and juvenile and adult dermatomyositis, and in cases with associated connective tissue diseases, suggesting different underlying pathogenetic mechanisms. Inclusion body myositis, eosinophilic myositis, and granulomatous myositis can be separated from the other idiopathic inflammatory myopthies because of distinctive clinical and pathological features and this may also reflect different mechanisms of muscle injury. Recent developments in the treatment of the idiopathic inflammatory myopathies include the use of plasmapheresis and total-body irradiation in cases that are resistant to corticosteroids and immunosuppressive drugs.
TL;DR: In the frog Hyla moorei,Optic axon counts and retrograde transport of horseradish peroxidase (HRP) indicated that 72–76% of these were ganglion cells, and cells of this type were distributed as a temporally situated area centralis within a horizontal visual streak.
Abstract: In the frog Hyla moorei we have estimated there to be between approximately 450,000 and 750,000 cells in the retinal ganglion cell layer. Optic axon counts and retrograde transport of horseradish peroxidase (HRP) indicated that 72–76% of these were ganglion cells. Cells of this type were distributed as a temporally situated area centralis within a horizontal visual streak.
Cell and optic axon counts showed that there was an approximately 40% loss of ganglion cells during optic nerve regeneration. Ganglion cells appeared chromatolysed by 6–8 days after an extracranial nerve crush but there was no indication of cell death until 15 days. By this stage anterograde transport of HRP indicated that axons had reached the chiasma. Death was first seen in the area centralis, extended along the streak, and finally was observed in the periphery by 65 days; cell counts demonstrated that at this time the wave of death was almost complete. We have previously shown by electrophysiological visual mapping (Humphrey and Beazley, 1982) and confirmed in this study that visuotectal projections were retinotopically organized during regeneration. Multiunit receptive fields were initially large but progressively refined starting in nasal field (temporal retina) to restore a normal projection. The similar sequences whereby the visuotectal projection became refined and death took place in the retinal ganglion cell layer suggested that death may be related to a process of organization within the regenerating projection.
In normal animals primary visual pathways revealed by anterograde transport of HRP were essentially similar to those of Rana pipiens and R. esculenta. Regenerating axons generally remained within optic pathways. Exceptions were a retinoretinal projection which was not completely withdrawn even after 1,028 days and a direct projection to the ipsilateral tectum via an inappropriate part of the optic tract.
TL;DR: Observations of the pre-retinal partial pressure of oxygen (PO2) in the cat eye indicate that the retinal arterial walls offer easy diffusion for oxygen, and that at 100% O2 breathing almost all the oxygen offloaded from the Retinal circulation is from dissolved oxygen.
Abstract: Detailed measurements have been made of the pre-retinal partial pressure of oxygen (PO2) in the cat eye to determine the effect of the local geometry of the retinal circulation on vitreal PO2 values. Measurements were made with oxygen sensitive microlectrodes for two ventilation conditions: air and 100% O2 breathing. PO2 gradients, which may extend as far as 800 µm from the internal limiting membrane, have been shown to exist in the vicinity of retinal arteries. Close to a retinal vein there is either a very shallow PO2 gradient or none at all. Coarse vitreal PO2 profiles which were measured out to the “mid vitreous” show that the gradients are very shallow to within 1 mm of the retina. The close agreement between “mid vitreous” PO2 and retinal venous PO2 implies that the retinal venous PO2 sets the PO2 value of the main bulk of the vitreous. Absolute PO2 values indicate that the retinal arterial walls offer easy diffusion for oxygen, and that at 100% O2 breathing almost all the oxygen offloaded from the ...