Showing papers by "Monash University published in 1989"
TL;DR: The detachment terranes are relatively young features, formed late in the geological evolution of these bodies, and are only the last in a succession of low-angle normal faults that sliced through the upper crust at the upward terminations of major, shallow-dipping, ductile shear zones in the Cordilleran orogen as mentioned in this paper.
923 citations
TL;DR: The Project to Enhance Effective Learning (the peel project) as mentioned in this paper is an example of a project that aims to promote metalearning in a secondary school, and some general principles derived from the experience of the project are outlined.
Abstract: Conceptual change means the commitment to a new belief about a principle or a phenomenon, and the abandoning of an old one. Promotion of a new belief is relatively easy, but it is difficult to get students to abandon their former beliefs. Conflicting beliefs can be held by a learner. This article argues that the resolution of conflicting beliefs requires elements of metalearning (conscious control over one's learning). The work of the Project to Enhance Effective Learning (the peel project), which attempts to promote metalearning in a secondary school is described and some general principles derived from the experience of the project are outlined. It is suggested that the key to the acceptance of metalearning strategies by students parallels the conditions for promoting conceptual change specified by Posner et al. (1982) and in particular in the acceptance of the fruitfulness of the new approaches. It is argued that this requires changes in the organization of schooling, particularly adoption of methods o...
245 citations
TL;DR: Investigation of spermatogenesis in the rat by cryptorchidism, heat treatment, or efferent duct ligation results in a decline in inhibin levels and a rise in FSH levels, findings consistent with the negative feedback action of inhibin on FSH secretion.
Abstract: Inhibin, a glycoprotein that preferentially suppresses follicle-stimulating hormone (FSH) secretion, has been isolated from follicular fluid as a heterodimer of two dissimilar subunits linked by disulphide bonds. The larger subunit is termed alpha and the smaller is designated beta. Two forms of inhibin termed A and B have been isolated, the differences being due to variations in the amino acid sequence of the beta-subunit; Inhibin A consists of alpha-beta and Inhibin B of alpha-beta B. Dimers of the beta-subunit, termed activins, have also been found in follicular fluid; these stimulate pituitary FSH secretion. Inhibin is produced in the female by the granulosa cell and corpus luteum under the control of FSH and luteinizing hormone (LH), respectively. The levels in serum rise to peak at mid-cycle and in the mid-luteal phase of the human menstrual cycle, and decline prior to menstruation. In pregnancy, the late-luteal phase decline in inhibin does not occur and the levels increase slowly. Studies suggest that the levels in pregnancy arise from an embryonic source, particularly the placenta. In the male, inhibin is produced by the Sertoli cells under the control of FSH by mechanisms involving cyclic adenosine 3', 5'-monophosphate. Testosterone exerts a minor inhibitory control at supraphysiological levels (10(-5) M), but human chorionic gonadotropin stimulation results paradoxically in a rise in serum inhibin levels. Disruption of spermatogenesis in the rat by cryptorchidism, heat treatment, or efferent duct ligation results in a decline in inhibin levels and a rise in FSH levels, findings consistent with the negative feedback action of inhibin on FSH secretion. As well as their roles in the reproductive system, inhibin and activin have more widespread actions in the haemopoietic, immune and nervous systems as evidenced by the finding of mRNA for its subunits in a range of tissues. Other studies have shown actions on erythroid differentiation and on mitotic activity in thymocytes. These actions suggest that inhibin and activin may function as growth factors as well as regulators of FSH.
227 citations
26 Jun 1989
TL;DR: In this paper, an alternative PWM strategy based on AC-AC matrix converter theory, which generates only high-order switching harmonics, presents a unity power factor load to the supply, implicitly extends to regeneration and operation with a center tapped DC output, and is feasible to physically implement for real-time output voltage control.
Abstract: It is well known that a PWM-controlled rectifier can offer advantages of reduced low-order harmonics and unity input power factor when compared to a conventional thyristor converter. However, theoretically optimum PWM strategies are often difficult to implement physically or are not easily extended to regenerative operation. The authors propose an alternative PWM strategy based on AC-AC matrix converter theory, which generates only high-order switching harmonics, presents a unity power factor load to the supply, implicitly extends to regeneration (and operation with a center tapped DC output), and is feasible to physically implement for real-time output voltage control. Both the theory and physical simulation results are presented. >
223 citations
157 citations
TL;DR: It is suggested that smoking is a more potent risk factor for the most common form of ischaemic stroke than has previously been appreciated and the persistent nature of the risk even after cessation of smoking and the possible risk associated with passive exposure strengthens public health arguments against smoking.
148 citations
140 citations
TL;DR: The Impersonal Total Principle (ITP) as discussed by the authors has been adopted for comparison concerning future generations, where our own interests are affected, trading off our concern for future (or others') goodness with our self-interests.
Abstract: Parfit's requirements for an ideal Theory X cannot be fully met since the Mere Addition Principle and Non-Antiegalitarianism imply the Repugnant Conclusion: Theory X does not exist. However, since the Repugnant Conclusion is really compelling, the Impersonal Total Principle should be adopted for impartial comparisons concerning future generations. Nevertheless, where our own interests are affected, we may yet choose to be partial, trading off our concern for future (or others') goodness with our self-interests. Theory X' (maximization of number-dampened total utility) meets all Parfit's requirements except the Mere Addition Principle in less compelling cases.
132 citations
TL;DR: It is demonstrated that Leydig cells express mRNA for the a-subunit of inhibin and produce inhibin which is biologically and immunologically active prompting a re-evaluation of the concepts of testicular inhibin production.
132 citations
TL;DR: A reliable and efficient method has been developed for the electroporation-mediated transformation of Clostridium perfringens with plasmid DNA, and cells harvested early in the logarithmic stage of growth were transformed more efficiently than cells at other growth phases.
118 citations
TL;DR: In this paper, the microwave spectrum of the nucleic acid base adenine in a cw seeded supersonic beam has been analyzed indicating that the amino, N (9) H tautomer is the most stable in an isolated environment.
TL;DR: The failure of serum concentrations of inhibin to correlate with those of FSH levels or the degree of testicular damage raise questions as to the clinical value of this parameter alone.
Abstract: Serum concentrations of inhibin, FSH and LH were measured in 39 normal men and 127 men with testicular disorders resulting in infertility. The infertile men were divided into groups on the basis of their mean sperm count, FSH levels and karyotype. The mean (+/- S.D) serum concentrations of inhibin in the normal men was 554 +/- 156 U/l and did not differ significantly from those groups with oligospermia, azoospermia or Klinefelter's syndrome. Combined analyses of all groups did not reveal any significant correlation between serum concentrations of inhibin and FSH or with any other parameter measured. Serum concentrations of FSH and LH were positively correlated, and Leydig cell dysfunction, as evidenced by increased serum LH levels, low testosterone levels or a declining testosterone/LH ratio were found with severe spermatogenic damage. The failure of serum concentrations of inhibin to correlate with those of FSH levels or the degree of testicular damage raise questions as to the clinical value of this parameter alone.
TL;DR: It is concluded that further improvements in outcome will be difficult to achieve, but that efforts should be directed towards the earlier diagnosis of diabetes and the earlier recognition and treatment of associated acute pulmonary and vascular complications.
Abstract: We assessed the possibility of improvements in the management of the potentially fatal acute hyperglycaemic complications of diabetes by a review of all deaths in patients who presented to the Alfred Hospital, Melbourne, with diabetic ketoacidosis or hyperosmolar coma during the 16 years, 1973-1988 All late deaths of patients during hospitalization were included in the mortality data In the 610 episodes of diabetic ketoacidosis (pH, 730 or lower) or hyperosmolar coma (osmolality, 350 mOsmol/kg or greater), only one death occurred as a result of the acute metabolic disturbance--in a patient who had suffered a cardiac arrest before admission to hospital The over-all mortality rate was 62% (38 deaths) The mortality rate was 49% (26 deaths) for 528 episodes of diabetic ketoacidosis and 146% (12 deaths) for 82 episodes of hyperosmolar coma Patients with diabetic ketoacidosis who died were older than were those who survived (64 +/- 13 years compared with 40 +/- 21 years, respectively; P less than 0001) Mortality in patients with hyperosmolar coma did not relate to age, initial blood-glucose level or osmolality Twelve deaths resulted from bacterial pneumonia and two deaths resulted from aspiration pneumonia Other major causes of death were mesenteric and iliac thromboses (six cases), myocardial infarction (eight cases) and cerebral haemorrhage (two cases) Of the 26 deaths that were associated with diabetic ketoacidosis, only two deaths--as a result of aspiration pneumonia and bowel infarction, respectively--were assessed as potentially avoidable after the patient's admission to hospital Eight of the 12 hyperosmolar-coma-associated deaths occurred in newly recognized diabetic patients in whom there were avoidable delays in diagnosis We conclude that further improvements in outcome will be difficult to achieve, but that efforts should be directed towards the earlier diagnosis of diabetes and the earlier recognition and treatment of associated acute pulmonary and vascular complications
TL;DR: Analyses of microflora and microfauna from two sites within the Tower Hill volcanic complex of western Victoria have provided a detailed and consistent record of vegetation and environments through the last 11,000 years as mentioned in this paper.
Abstract: Analyses of microflora and microfauna from two sites within the Tower Hill volcanic complex of western Victoria have provided a detailed and consistent record of vegetation and environments through the last 11,000 years. One of these sites extends the record back to 20,000 years BP and is the first from this intensively studied part of Australia to cover the whole of this period. From about 20,000 to 15,000 years ago, shallow, slightly brackish water was present in Tower Hill lakes whilst surrounding vegetation was of a cool-steppe type, with no known modern analogue, existing under climatic conditions that were cooler, drier and probably windier than today. Maximum aridity, as indicated by higher salinity levels and lake drying, occurred between 15,000 and 11,500 BP largely as a result of increasing temperatures. Effective precipitation then increased gradually to maximum Holocene levels between about 8000 and 5000 years BP before a reduction to
TL;DR: Follicle stimulating hormone (FSH) suppressing protein (FSP) which has inhibin-like activity accelerated the rate of meiotic maturation of rat oocytes in culture and activin, which has opposite biological effects to inhibin in many systems did not significantly stimulate oocyte maturation at a dose of 1.12 micrograms/ml.
TL;DR: The authors determined the prevalence of mental illness in 382 people representative of the occupants of shelters for the homeless and cheap single-room accommodations in inner-city areas of Melbourne, finding considerable comorbidity.
Abstract: The authors determined the prevalence of mental illness in 382 people representative of the occupants of shelters for the homeless and cheap single-room accommodations in inner-city areas of Melbourne. Clinicians were trained to use a standardized diagnostic instrument, the Structured Clinical Interview for DSM-III-R, to diagnose a range of severe mental disorders, including psychotic, affective, and substance-related disorders. Almost half the people interviewed received diagnoses of current disorders, and over 70% received lifetime diagnoses. There was considerable comorbidity. Many factors are likely to contribute to the concentration of people with mental disorders in such homeless and disaffiliated groups.
TL;DR: Genealogie et evolution du concept de culture en anthropologie, de son insertion dans le cadre de l'anthropologie reflexive, and des proximites conceptuelles historiquement reperables entre culture and race, mais conclusion sur l'impossibilite (actuelle) de lui substituer un autre concept as discussed by the authors.
Abstract: Genealogie et evolution du concept de culture en anthropologie, de son insertion dans le cadre de l'anthropologie reflexive, et des proximites conceptuelles historiquement reperables entre culture et race, mais conclusion sur l'impossibilite (actuelle) de lui substituer un autre concept
TL;DR: In this paper, carbon and oxygen isotope data from carbonate cements in concretions have been used to infer the isotopic composition of meteoric fluids present at the time of concretion growth in terrestrial sediments that were deposited within the early Cretaceous South Polar Circle at 75-80°S.
TL;DR: The enhanced production of reactive oxygen species by glomerular macrophages in this macrophage dependent model of glomerulonephritis suggests that these mononuclear cells are locally activated within the glomerulus following recruitment from the circulation.
TL;DR: It is concluded that an intravenous infusion of 1.0 g/kg of mannitol which is given over 45 minutes, after rehydration if required, can be of significant benefit to at least some acutely intoxicated victims of ciguatera poisoning.
Abstract: Ciguatera is a distressing, hitherto-untreatable and not rare disease which results from the eating of ciguatoxin-contaminated fish from tropical and subtropical waters. We report here the results of a pilot study to assess the efficacy of mannitol therapy in ciguatera poisoning. Twelve adult patients (six men) have been treated, five of whom--who were ill acutely--experienced a significant benefit from this therapy, in three cases, with a hitherto-unexperienced dramatic reversal of symptoms. We conclude that an intravenous infusion of 1.0 g/kg of mannitol which is given over 45 minutes, after rehydration if required, can be of significant benefit to at least some acutely intoxicated victims. We postulate either a reduction of axonal oedema, or a scavenger effect, or both, as the mechanism of the beneficial effects of mannitol. Ciguatoxin is rich in hydroxyl groups, and causes microscopic oedema of neural tissue. If our conclusion of the beneficial effects of mannitol therapy is confirmed, this will offer the first effective therapy for acute phases of this disease, and has promise of preventing much long-term morbidity.
TL;DR: In this article, the authors investigate the occurrence of large negative peak pressures near the leading edge of sharp-edged bluff bodies and show that negative peak pressure is produced when the separated shear layer rolls up to form a large vortex near the surface.
TL;DR: It is suggested that C. pylori and associated histological gastritis may play a role in non-ulcer dyspepsia and histological improvement was associated with a significant decrease in symptoms.
Abstract: Non-ulcer dyspepsia (NUD) is a common complaint in which no systematic illness or organic proximal alimentary tract disease can be identified. The pathophysiology of NUD is probably heterogeneous. Eighty-two subjects with NUD were studied in a prospective randomized placebo-controlled study to assess the efficacy of colloidal bismuth subcitrate (CBS) chewable tablets at a dose of four tablets daily for 1 month. The role of Campylobacter pylori and associated histological gastritis was evaluated. Sixty-one percent of NUD patients had C. pylori in the gastric antrum compared with 25% of age-matched controls. C. pylori was associated with acute and chronic inflammation (P < 0.001) in the antrum. C. pylori was cleared in 59% of CBS-treated subjects compared with only 4% placebo (P < 0.05). Both acute and chronic inflammation improved in subjects cleared of bacteria. Clearance of C. pylori and histological improvement was associated with a significant decrease in symptoms. In C. pylori negative subjects improv...
TL;DR: Results show that the myocardium can respond to dilatation by an activation of the phosphatidylinositol turnover pathway, as measured by an increase in the accumulation of inositol phosphates.
Abstract: The mammalian myocardium responds to stretch by increasing both contractility and the release of atrial natriuretic peptide. These effects are observed in isolated perfused heart preparations as well as in vivo. That atrial natriuretic peptide release can be stimulated by activation of the phosphatidylinositol turnover pathway suggests a possible mechanism by which stretch might activate a biological response. Accordingly, experiments were performed to examine the effect of dilatation of the right atrium on the phosphatidylinositol turnover pathway measured in isolated perfused hearts. Dilatation of the right atrium caused a stimulation of the phosphatidylinositol turnover pathway as measured by an increase in the accumulation of inositol phosphates. In right atria, increases were detected after 1 minute of dilatation, and maximal increases were observed after 10 minutes. Dilatation for 10 minutes caused an increase in inositol monophosphate, inositol bisphosphate, and inositol trisphosphate from 23.3 +/- 0.9, 15.4 +/- 0.4, and 9.5 +/- 0.3 cpm/mg tissue (mean +/- SEM, n = 7) to 74.6 +/- 2.3, 20.2 +/- 1.3, and 13.6 +/- 1.5 cpm/mg tissue (n = 8), respectively (p less than 0.01 for all inositol phosphates). Smaller increases were observed in the other chambers of the hearts. Perfusion with propranolol, prazosin, and atropine (all 1 microM) did not alter the inositol phosphate response to dilatation, indicating that it was not secondary to release of norepinephrine or acetylcholine. Dilatation of the right ventricle also caused a stimulation of inositol phosphate accumulation, but this was lower than after dilatation of the right atrium. These results show that the myocardium can respond to dilatation by an activation of the phosphatidylinositol turnover pathway.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: In this article, the authors modified the language reversion hypothesis to the extent that there seems to be some kind of "critical threshold" that has to be reached in order to retain the second language.
Abstract: In the 1970s, Clyne conducted linguistic research on German-English and Dutch-English bilinguals in Australia. In the course of the study, he found evidence for second language attrition and first language reversion among his elderly informants (Clyne, 1981). In 1987, some 40 of the 200 Dutch informants tested in 1971 were retested in order to get longitudinal data on language maintenance and loss. The data show surprisingly little loss of proficiency in both Dutch and English over the years. This calls for a revision of the language reversion hypothesis as stated by Clyne in 1981. In the present article the hypothesis is modified to the extent that there seems to be some kind of “critical threshold” (Neisser, 1984) that has to be reached in order to retain the second language. First language reversion seems to be a common phenomenon among those immigrants who did not reach this threshold, but not among immigrants who did.
Journal Article•
TL;DR: It is suggested that intrachondrocyte oxidant damage occurs through oxidation of the sensitive thiol (-SH) residue at the active center of G-3-PDH, with subsequent reduction in the rate of glycolytic ATP synthesis and the intracellular concentration of ATP which is required for DNA, protein, proteoglycan and hyaluronic acid synthesis.
Abstract: Exposure of articular cartilage to H2O2 in vitro inhibits proteoglycan synthesis in a fashion which parallels the inhibition which occurs in cartilage in animal models of acute inflammation. Our study shows that exposure to H2O2 also inhibits other chondrocyte functions, including total protein and DNA synthesis. Since these intracellular biosynthetic processes require adenosine triphosphate (ATP), the effect of exposure of H2O2 on chondrocyte ATP was measured. Exposure to H2O2 caused an immediate (less than 2 min) dose dependent decrease in cartilage ATP levels--found to be due to the oxidative inactivation of glyceraldehyde-3-phosphate dehydrogenase (G-3-PDH). We suggest that intrachondrocyte oxidant damage occurs through oxidation of the sensitive thiol (-SH) residue at the active center of G-3-PDH, with subsequent reduction in the rate of glycolytic ATP synthesis and the intracellular concentration of ATP which is required for DNA, protein, proteoglycan and hyaluronic acid synthesis.
01 Jan 1989
TL;DR: The authors discuss the role played in syntactic comprehension by thematic roles and several other issues about the structures of language comprehension will be considered in the context of examining the role of thematic role in sentence comprehension.
Abstract: This paper will discuss the concept of thematic roles and their possible role in sentence comprehension. Thematic roles (Gruber, 1976; Fillmore, 1969; Jackendoff, 1972; Chomsky, 1981, 1982) relate arguments of a word, such as the object of a verb, to the meaning of that word. For instance, the object of put is a theme, or affected object; it is the entity that is moved when an act of putting takes place. Within the context of examining the role played in syntactic comprehension by thematic roles, several other issues about the structures of language comprehension will be considered.
TL;DR: Stereological studies were performed to determine the number of Sertoli cells present during the postnatal development of the rat testes, and indicate that the newborn rat testis contains 1.3 +/- 0.2 x 10(6) SERToli cells and that this number increases to 38.4 +/- 2.7 x 10 (6) at day 15.
Abstract: Stereological studies were performed to determine the number of Sertoli cells present during the postnatal development of the rat testes. Sprague-Dawley rats aged from 1 to 70 days were used in two experiments, and in each were fixed by vascular perfusion and embedded in Epon-Araldite, subsequent to which 1 micron sections stained with Toluidine blue were prepared. In the first experiment, rats aged from 1 to 20 days were used in groups of three, and number estimates were made using a direct counting method. In the second, which used groups of four rats aged from 20 to 70 days, a point sampled intercept was used to estimate nuclear volume and thence number. The results of the experiments indicate that the newborn rat testis contains 1.3 +/- 0.2 x 10(6) Sertoli cells and that this number increases to 38.4 +/- 2.7 x 10(6) at day 15. No further increase in Sertoli cell number occurred thereafter up to day 70 of age.
TL;DR: The current evidence does not support screening for lung cancer with chest radiography or sputum cytology and further data are required on the cost effectiveness of screening and the relative harms and benefits of screening across a range of different risk groups and settings.
Abstract: Lung cancer incidence is increasing. Survivability has increased over the last few years particularly in certain subsets and has also been shown to increase with early detection. Chest X-ray and sputum cytology have been the mainstays of screening programs. Although survival is increased, overall mortality rates seem unchanged except in certain subsets. Whether the addition of serum markers or use of monoclonal antibodies, automated cytological, and computer-aided techniques will show decrease in mortality remains to be documented. We recommend yearly chest X-rays, sputum cytology in high-risk patients, i.e., age greater than 65, greater than 20 year history smoking, other significant carcinogenic exposure. Serum markers, monoclonal antibodies, and advanced, automated cytology methods are yet to be tested and therefore should be considered in clinical trials only.
TL;DR: An index of food variety was examined for its ability to predict changes in the arterial wall and significant correlations, both parametric and nonparametric, were found.
Abstract: In developed countries, the health outcome most under scrutiny with respect to food intake is macrovascular disease. Since food is so complex, global indices of food intake are required to assess the relation. In the present study, an index of food variety was examined for its ability to predict changes in the arterial wall. Arterial wall indices were measured noninvasively by Doppler ultrasound in patient with Type II diabetes and in matched apparently healthy subjects. Each subject kept a 7-day food record, which was cross-checked by a nutritionist so as to calculate an index of food variety. The arterial wall indices measured were compliance over the aorto-iliac segment and pulse wave damping at the common femoral and posterior tibial arteries. Significant correlations, both parametric and nonparametric, were found between total food variety, and plant food variety, and each arterial wall index when the diabetics and apparently healthy subjects were grouped together (p less than 0.01 in all cases for t...
TL;DR: The survival, fertilization, development, and viability in vitro and in vivo of unfertilized mouse eggs frozen by slow cooling in 1.5 M dimethyl sulphoxide (DMSO) was examined in a series of experiments which explored some of the problems in freezing the egg.