Showing papers by "RMIT University published in 1994"

Postmodernism and Education: Different Voices, Different Worlds

Abstract: Introduction 1. Postmodernism, Postmodernity and the Postmodern Moment 2. Speaking 'Truthfully': Science, Psychology and Subjectivity 3. Knowing Oneself: Subjectivity and Mastery 4. Subject Disciplines and Disciplining Subjects: The Subject in Education 5. Examining the Case: Competences and Management 6. The 'End' of the Educational Project 7. Education and Textuality 8. Telling Stories: The Legitimising of Knowledge 9. The End of the Story: Education, Efficiency and Resistance 10. The Cultivation of Desire 11. Catching the (Last) Post References Index

Excimer laser in situ keratomileusis and photorefractive keratectomy for correction of high myopia.

Abstract: Background The purpose of this research was to study the visual outcome of excimer laser photorefractive keratectomy and laser in situ keratomileusis (LASIK) for the correction of moderate and high myopia. Methods Twenty partially-sighted eyes of 20 patients were divided into two groups, LASIK and photorefractive keratectomy. Ten eyes underwent LASIK and the other 10 photorefractive keratectomy. Follow up was at 1, 3, 6, and 12 months. The LASIK technique included a nasally based, 150 microns thick, 8.0 x 9.0 mm diameter, truncated, disc-shaped corneal flap created with a microkeratome; and the ablation of the stroma with a 193-nanometer ArF excimer laser. The flap was returned to its original position and held in place by apposition. The photorefractive keratectomy technique included mechanical removal of the epithelium and ablation of the stroma with a 193-nanometer ArF excimer laser. Results LASIK series: One eye had a ruptured globe during the second postoperative month and was excluded from the study. The preoperative spherical equivalent refraction ranged from -10.62 to -25.87 diopters (D). The attempted correction ranged from -8.00 to -16.00 D. Postoperative refraction and corneal topography stabilized between 4 and 12 weeks. Spectacle-corrected visual acuity was within 1 Snellen line of preoperative in all eyes. The refraction in six eyes (66.6%) was within +/- 1.00 D of the intended correction, and in eight eyes was within +/- 2.00 D (88.8%) at 12 months. The mean attempted correction (11.40 +/- 2.60 D) was close to the mean achieved correction at 12 months (11.96 +/- 3.10 D). The mean postoperative refractive astigmatism (1.50 +/- 0.97; range, 0.25 to 3.50 D) was close to the preoperative astigmatism (1.70 +/- 1.15; range, 0 to 3.75 D). Endothelial cell density at 12 months showed an average 8.67% of cell loss. All eyes showed a clear interface. Photorefractive keratectomy series: The preoperative spherical equivalent refraction ranged from -10.75 to -23.12 D. The attempted correction ranged from -8.80 to -17.60 D. Postoperative refraction showed regression throughout the follow-up period, and corneal topography did not stabilize. Spectacle-corrected visual acuity was within 1 Snellen line in eight eyes. Two eyes lost 2 and 3 Snellen lines. One eye was within +/- 1.00 D, and three eyes (30%) were within +/- 2.00 D of the intended correction at 12 months. The achieved correction mean (7.17 +/- 5.29 D) was 61% of the attempted mean (11.72 +/- 2.81 D) at 12 months. The postoperative refractive astigmatism (1.80 +/- 0.95; range, 0.50 to 4.00 D) was very close to the preoperative (1.90 +/- 1.33; range, 0 to 5.00 D). Endothelial cell density showed an average of 10.56% cell loss at 12 months. The mean haze at 12 months was 1.2 (0 to 4 scale). Conclusion LASIK, although more complicated because of the use of a microkeratome, was more effective than photorefractive keratectomy in higher myopes. LASIK created less corneal haze. The refraction was more stable with LASIK in the correction of high myopia. Its predictability was three times that of PRK.

Effective retrieval of structured documents

Abstract: Information systems usually retrieve whole documents as answers to queries. However, it may in some circumstances be more appropriate to retrieve parts of documents. We consider formulas for retrieving whole documents and parts of documents horn a large structured document collection. We consider what information is needed to retrieve effectively and show that knowledge of the structure of documents can lead to improved retrieval performance.

The Inhibitory Effects of Tea Polyphenols (Flavan-3-ol Derivatives) on Cu2+ Mediated Oxidative Modification of Low Density Lipoprotein

Abstract: Tea polyphenols (flavan-3-ol derivatives) suppressed the oxidative modification of low density lipoprotein (LDL) which is assumed to be an important step in the pathogenesis of atherosclerosis lesions. Inhibitory experiments on the oxidative impairment of porcine serum LDL by flavan-3-ols were carried out by incubating them at 37 degrees C in the presence of 5 microM Cu2+. The oxidation of LDL was monitored either by an absorption increase at 234 nm due to the conjugated diene formation, or the formation of hydroperoxides and thiobarbituric acid reactive substances (TBARS). It was found that the oxidation was strongly inhibited by various flavan-3-ols, and a lag time over 100 min appeared, depending on the types of flavan-3-ols used. The activities based on the prolongation of the lag time were in the order of (-)-epigallocatechin (EGC) < (+)-catechin (C) < (-)-epicatechin (EC) < (-)-epicatechingallate (ECG) < (-)-epigallocatechingallate (EGCG). IC50 of flavan-3-ols on Cu2+ mediated hydroperoxides and TBARS formation of LDL were 0.90, 0.95 microM for ECG and 2.38, 2.74 microM for EGC, respectively. It was found that the Cu2+ mediated cholesterol ester degradation in LDL was almost completely inhibited by 5.0 microM C or EGCG. Cu2+ mediated apolipoprotein B-100 fragmentation was also inhibited (up to 60%) in the presence of C or EGCG.

Low level laser therapy for dentinal tooth hypersensitivity

Abstract: A comparative double blind study testing low level laser therapy (Gallium/Aluminium/Arsenide laser [GaAlAs]) against placebo was carried out in the management of dentinal tooth hypersensitivity. Subjects demonstrating dentinal hypersensitivity and complying with strict selection criteria were randomly assigned to an active and placebo group. Low level laser therapy was applied for one minute to both the apex and cervical area of the tooth; and reapplied at one week, two-week and eight-week intervals. Dentinal hypersensitivity was rated at each visit. There were 28 subjects in the placebo group and 22 and 21 subjects, respectively, in the tactile sensitivity and thermal sensitivity groups. Comparisons between the groups were conducted using independent groups t-test. In both the tactile and thermal sensitivity groups differences between the active and placebo groups were significant from the first week and increased further in the second and eighth weeks. The mean value of thermal sensitivity decreased 67 per cent (p < 0.001) compared with placebo (17 per cent) and tactile sensitivity decreased 65 per cent (p = .002) compared with placebo (21 per cent) at eight weeks. Results demonstrate that the GaAlAs laser is an effective method for the treatment of both thermal and tactile dentinal hypersensitivity. There were no reported adverse reactions or instances of oral irritation.

The Anatomy and Physiology of Primate Neurons that Control Rapid Eye Movements

Abstract: Primates are frontal eyed animals possessing a sophisticated retina endowed with a highly differentiated foveal region with which the visual scene can be examined in detail. Vision is very important to these animals and is probably the predominant sensory modality with which they orient themselves and interact with the world. The relationship between the visual system and the motor system that moves the eyes (oculomotor) is intimate. Motion of the visual scene across the retina, particularly the fovea, can degrade visual acuity. Hence there is a necessity for accurate oculomotor control. Not surprisingly, a considerable portion of the brain� including the superior colliculus (sq, the frontal eye field (FEF), the thalamus, and the cerebellum as well as several brainstem nuclei, is entrusted with the control of eye movements (Hepp et al 1989). The most ubiquitous movements of the eyes are the rapid ones (also called saccadic) that reorient the eyes quickly toward interesting features of the surrounding world. During a saccade, two or more of six extraocular muscles

Electronic publishing of professional articles: attitudes of academics and implications for the scholarly communication industry

Abstract: The study sought to answer the question, “What contribution, if any, can the publishing of professional articles in electronic form make to scholarly and research communication?” The professional article, arguably more than any other form of research communication, is seen as fundamental to the Western system of scholarship. A state-of-the-art review, and a survey of academics in Australia, the United Kingdom, and the United States covered the following themes: origins of professional articles; state of the printed journal; electronic publishing—pioneering research and development; publishing via commercial database hosts; publishing via the Internet and related academic networks; publishing via portable electronic media; tensions in document supply and interlending; academics as authors and readers of professional articles, and universities as publishers. Responses of 582 academics in Australia, the United Kingdom, and the United States to a survey in the second half of 1992 enabled an assessment of the position of academics in relation to electronic publishing. Evidence was interpreted through two complementary theoretical perspectives which allowed electronic publishing to be viewed (a) as a process of technologically induced structural change across an industry, and (b) as a means of increasing efficiency and gaining competitive advantage. It was concluded that the contribution of electronic publishing lies in greater diversity and choice in a marketplace where at-source-subsidized publishing competes with fee-for-service publishing. Recommendations are made for new relationships among academics, publishers, libraries, and universities. © 1994 John Wiley & Sons, Inc.

Isolation and characterization of a cDNA clone corresponding to the Rt locus of Petunia hybrida

Abstract: Summary We have isolated, via differential screening of a Petunia hybrida petal cDNA library, a cDNA clone that corresponds to the Rt locus which controls the conversion of anthocyanidin-3-glucosides to anthocyanidin-3-rutinosides by the UDP rhamnose: anthocyanidin-3-glucoside rhamnosyltransferase (3RT). The cDNA encodes a 469 amino acid long polypeptide with regions of similarity to the UDP glucose: flavonoid glucosyltransferases (3GT) from barley and maize. Some sequence similarity was also observed with non-plant glycosyltransferases. Two aberrant transcripts are present in most of the rt/rt petunia lines examined. Excision of a transposon from an unstable Rt locus of one petunia line (Tr38) is associated with a change in transcript size back to wild-type. The Rt transcript is most abundant in petals from flowers at an early stage of development and levels decline as the flower matures. Transcripts are also detected in the style and anthers but not in leaf, stem, root, petiole, ovary or sepals. Incubation of leaves in glucose under high light conditions induces the expression of the Rt gene as well as other flavonoid pathway genes. In situ hybridization revealed that the Rt transcript predominantly accumulates in the epidermal cells of the petal, the site of anthocyanin accumulation.

Focused interplanetary transport of approximately 1 MeV solar energetic protons through self-generated Alfven waves

Abstract: We present a model of the focused transport of approximately 1 MeV solar energetic protons through interplanetary Alfven waves that the protons themselves amplify or damp. It is based on the quasi-linear theory but with a phenomenological pitch angle diffusion coefficient in the 'resonance gap.' For initial Alfven wave distributions that give mean free paths greater than approximately 0.5 AU for approximately 1 MeV protons in the inner heliosphere, the model predicts greater than roughly an order of magnitude amplification (damping) in the outward (inward) propagating resonant Alfven waves at less than or approximately equal to o.3 AU heliocentric distance. As the strength of proton source is increased, the peak differential proton intensity at approximately 1 MeV at 1 AU increases to a maximum of approximately 250 particles (/(sq cm)(s)(sr)(MeV)) and then decreases slowly. It may be attenuated by a factor of 5 or more relative to the case without wave evolution, provided that the proton source is sufficiently intense that the resulting peak differential intensity of approximately 1 MeV protons at 1 AU exceeds approximately 200 particles (/(sq cm)(s)(sr)(MeV)). Therefore, in large solar proton events, (1) one may have to take into account self-amplified waves in studying solar particle propagation, (2) the number of accelerated protons escaping from a flare or interplanetary shock may have been underestimated in past studies by a significant factor, and (3) accelerated protons escaping from a traveling interplanetary shock at r less than or approximately equal to 0.3 AU should amplify the ambient hydromagnetic waves siginificantly to make the shock an efficient accelerator, even if initially the mean free path is greater than or approximately equal to 1 AU.

Document filtering for fast ranking

Abstract: Ranking techniques are effective for finding answers in document collections but the cost of evaluation of ranked queries can be unacceptably high. We propose an evaluation technique that reduces both main memory usage and query evaluation time. based on early recognition of which documents are likely to be highly ranked. Our experiments show that, for our test data, the proposed technique evaluates queries in 20% of the time and 2% of the memory taken by the standard inverted file implementation, without degradation in retrieval effectiveness.

Indices of free-radical-mediated damage following maximum voluntary eccentric and concentric muscular work.

Abstract: This study monitored plasma and skeletal muscle markers of free-radical-mediated damage following maximum eccentric and concentric exercise, to examine the potential role of free radicals in exercise-induced muscle damage. Fourteen male volunteers performed either (1) a bout of 70 maximum eccentric and a bout of 70 maximum concentric muscle actions of the forearm flexors (the bouts being separated by 4 weeks; n = 8) or (2) a bout of 80 maximum eccentric and a bout of 80 maximum concentric muscle actions of the knee extensors (the bouts being separated by 1 week; n=6). Plasma markers of lipid peroxidation, thiobarbituric acid-reactive substances (TBARS) and diene-conjugated compounds (DCC) were monitored in the arm protocol and skeletal muscle markers of oxidative lipid and protein damage, malondialdehyde (MDA) and protein carbonyl derivatives (PCD) respectively, were monitored in the leg protocol. In both protocols, the contralateral limb was used for the second bout and the order of the bouts was randomised between limbs. Repeated measures ANOVA indicated significant changes from baseline following eccentric arm work on the measures of serum creatine kinase activity (P < 0.05), maximum voluntary torque production (P < 0.01) and relaxed arm angle (P < 0.01). Subjective muscle soreness peaked 2 days after eccentric arm work (P < 0.05, Wilcoxon test). However, there were no changes in the plasma levels of TBARS or DCC following the eccentric or concentric arm exercise. Immediately after concentric leg exercise, skeletal muscle PCD concentrations was significantly higher than that observed immediately after eccentric work (P < 0.05). However, no significant difference between the eccentric and concentric knee extensor bouts was observed on the measure of skeletal muscle MDA concentration. The results of this study offer no support for the involvement of oxygen free radicals in exercise-induced muscle damage.

Long-term stability and psychometric properties of the Composite Scale of Morningness.

Abstract: Prompted by some discrepancies in the report detailing the development of the Composite Scale (CS) of Morningness (Smith et al. 1989) this study replicated the examination of the psychometric properties of the CS on a large sample (n = 424) of health science students. It was confirmed that the mean and range of CS scores previously reported were in error. The finding that the CS has good psychometric properties when used on samples of students was replicated and extended to a smaller (n = 35) sample of individuals working on rotating shifts. CS scores were found to be stable over time and did not change when subjects were exposed to night- and shiftwork.

An Improved Modification of Permanganate Oxidation of Eumelanin That Gives a Constant Yield of Pyrrole-2,3,5-Tricarboxylic Acid

Abstract: Microanalysis of eumelanin is based on the formation of pyrrole-2,3,5-tricarboxylic acid (PTCA) on permanganate oxidation followed by its HPLC determination. A problem in this method was that the oxidation gave concave, exponential curves when the amounts of PTCA formed were plotted against the amounts of sample oxidized. The problem has been mostly overcome by adding a homogenate of 5 mg of a mouse liver to the oxidation medium. Sepia melanin, C57BL black mouse hair, B16 mouse melanoma, and MM418 human melanoma cells were oxidized in the absence or presence of the liver homogenate. The yields of PTCA increased about 1.5-fold by adding the liver homogenate and the calibration curves became linear or almost linear. With the improved method the PTCA values from various types of samples can be reliably compared.

Neural network simulations of the primate oculomotor system

Abstract: The performance of a neural network that simulates the vertical saccade-generating portion of the primate brain is evaluated. Consistent with presently available anatomical evidence, the model makes use of an eye displacement signal for its feedback. Its major features include a simple mechanism for resetting its integrator at the end of each saccade, the ability to generate staircases of saccades in response to stimulation of the superior colliculus, and the ability to account for the monotonic relation between motor error and the instantaneous discharge of presaccadic neurons of the superior colliculus without placing the latter within the local feedback loop. Several experimentally testable predictions about the effects of stimulation or lesion of saccaderelated areas of the primate brain are made on the basis of model output in response to "stimulation" or "lesion" of model elements.

Evaluation of melanin‐related metabolites as markers of melanoma progression

Abstract: Background Urinary excretion of 5-S-cysteinyldopa (5-S-CD) has been used as a biochemical marker of melanoma progression Melanomas produce not only 5-S-CD but also 5,6-dihydroxyindole-2-carboxylic acid (5,6DHI2C) as major intermediates in melanin formation 5,6DHI2C is then metabolized to the two O-methyl derivatives, 5H6MI2C and 6H5MI2C The aim of this study was to determine which marker in serum and urine most sensitively reflected the progression of melanoma Methods Serum and 24-hour urine samples were collected and assayed serially by high-performance liquid chromatography every 1 to 4 months in 28 patients with primary or recurrent melanomas, for up to 48 months Results Serum concentration and urinary excretion of 5-S-CD and 6H5MI2C in patients with melanoma without metastases were close to those obtained from normal subjects Metastases developed in 9 of the 28 patients In seven of these nine patients, serum or urinary 5-S-CD values were elevated before or at the time of clinical detection of visceral metastases However, serum 5-S-CD was elevated significantly earlier and reflected melanoma progression better than the physical examination and/or laboratory tests, such as scintigraphy and echography Serum 6H5MI2C values exceeded the normal range shortly before death in three patients, and urinary 6H5MI2C did not increase at any stage in most patients, therefore these metabolites did not reflect progression of disease Conclusions Among the four markers, serum 5-S-CD appears to be the best biochemical marker for the detection of progression of melanotic melanoma, a value of more than 10 nmol/1 suggesting the presence of metastasis

Dielectric breakdown in high-ε films for ULSI DRAMs: II. barium-strontium titanate ceramics

Abstract: We present a study of breakdown fields in BaxSr1−xTiO3 ceramics as functions of thickness, temperature, applied voltage ramp rate, electrode material and cross-sectional area. The data show evidence of Zener-like breakdown mechanisms. The d.c. leakage currents at voltages below breakdown are dominated by tunneling injection and image forces at low voltages (≤3 V), Schottky behavior at intermediate voltages V a (3 V ≤ V a ≤ 6 V; 150 kV/cm ≤ E ≤ 300 kV/cm), and Fowler-Nordheim tunneling at high voltages; it is shown that both the Schottky emission regime and the ultimate breakdown arise from inter-grain effects rather than the BST/electrode interface, in accord with the theory of Neumann and Arlt and of Waser and Klee. In contrast to PbZrxTi1−xO3 (PZT), which displays avalanche breakdown and space-charge limited d.c. leakage currents at normal 5 V silicon IC voltages, BST exhibits Schottky-dominated leakage currents in this 5 V regime, and is dominated by Fowler-Nordheim tunneling in its breakdown ...

HIV infection of monocyte-derived macrophages in vitro reduces phagocytosis of Candida albicans.

Abstract: HIV-1 infection of peripheral blood monocyte- derived macrophages (MDMs) is unrelated to the level of CD4 expression on the surface of the cell, is associated with considerable donor variability, causes minimal cytopathology, and results in peak viral antigen produc- tion after 2 weeks of infection. Phagocytosis of opsonized Candida albicans by MDMs infected in vitro with several strains of HIV was compared with that of uninfected cells from the same donors; the proportion of MDMs contain- ing the fluorescein isothiocyanate - labeled yeast was de- termined by flow cytometry and phase contrast microscopy. The intracellular localization of C. albicans was confirmed by confocal microscopy. Using paired MDMs from nine donors, 81% ofuninfected and 53% of HIV-infected MDMs phagocytosed C. albicans. In addi- tion, the number of yeast per cell was significantly higher in uninfected MDMs than in HIV-infected cells (mean 6.1 versus 2.5). These findings may partially explain the high incidence of mucocutaneous candidiasis in HIV- infected patients with advanced disease. J. Leukoc. Biol. 56: 318-327; 1994.

Spatial Organisation of the Cooperatively Breeding Bell Miner Manorina melanophrys

Abstract: Bell Miners Manorina melanophrys are cooperative breeders and occur in discrete colonies. A colony comprised a number of breeding pairs occupying slightly overlapping foraging ranges that they shar...

Software-reliability growth model: primary-failures generate secondary-faults under imperfect debugging

Abstract: Little work has been done on extending existing models with imperfect debugging to the more realistic situation where new faults are generated from unsuccessful attempts at removing faults completely. This paper presents a software-reliability growth model which incorporates the possibility of introducing new faults into a software system due to the imperfect debugging of the original faults in the system. The original faults manifest themselves as primary failures and are assumed to be distributed as a nonhomogeneous Poisson process (NHPP). Imperfect debugging of each primary failure induces a secondary failure which is assumed to occur in a delayed sense from the occurrence time of the primary failure. The mean total number of failures, comprising the primary and secondary failures, is obtained. The authors also develop a cost model and consider some optimal release-policies based on the model. Parameters are estimated using maximum likelihood and a numerical example is presented. >

Electrospray Mass Spectrometric Analysis and Photocatalytic Degradation of Polyethoxylate Surfactants Used in Wool Scouring

Abstract: Electrospray mass spectrometry (ESMS) has been used to identify the mixture of components in three nonionic surfactants, nonylphenol ethoxylate (NPE), secondary alcohol ethoxylate (SAE), and primary alcohol ethoxylate (PAE). In each case singly protonated species are observed with the number of ethylene oxide units ranging from 4 to 16. Collisionally activated decomposition of protonated SAE leads to cleavage of the secondary carbon-oxygen bond to give protonatea ethylene oxide fragment ions. ESMS is used to show that the products of the photocatalytic decomposition of SAE are the same as those produced by the collisionally activated decompositions