Showing papers by "Curtin University published in 1990"

The effect of concept mapping on students' anxiety and achievement in biology

Abstract: The results of recent studies into the use of the concept mapping heuristic seem to demonstrate that meaningful learning results through its use in science classrooms. While this underscores the need to use more effective instructional strategies in science teaching, the issue of the intervening variable of anxiety in learning and science achievement, and the possible use of a metacognitive strategy in anxiety reduction have not been addressed. This study, therefore, sought to find out if the metacognitive strategy of concept mapping reduces anxiety and thereby enhances achievement in biology. A total of 51 (30 boys, 21 girls) senior secondary one (grade 10) students participated in this experiment. Two instruments—the Zuckerman Affect Adjective Checklist and the Biology Achievement Test—were used in pre- and posttest administrations to measure the treatment effect on anxiety and achievement, respectively. Findings support the stand that concept mapping is significantly more effective than the traditional/expository teaching strategy in enhancing learning in biology. In addition, it apparently reduces students' anxiety towards the learning of biology. A significant reduction of anxiety was noticed for male subjects.

What does it mean to be an exemplary science teacher

Abstract: In order to provide a refreshing alternative to the majority of research reports, which malign science education and highlight its major problems and shortcomings, a series of case studies of exemplary practice was initiated to provide a focus on the successful and positive facets of schooling. The major data-collection approach was qualitative and involved 13 researchers in hundreds of hours of intensive classroom observation involving 20 exemplary teachers and a comparison group of nonexemplary teachers. A distinctive feature of the methodology was that the qualitative information was complemented by quantitative information obtained from the administration of questionnaires assessing student perceptions of classroom psychosocial environment. The major trends were that exemplary science teachers (1) used management strategies that facilitated sustained student engagement, (2) used strategies designed to increase student understanding of science, (3) utilized strategies that encouraged students to participate in learning activities, and (4) maintained a favorable classroom learning environment.

An immunodominant antigen of Candida albicans shows homology to the enzyme enolase.

Abstract: Antibody to an immunodominant antigen of approximately 48 kDa is found in a high proportion of patients with mucocutaneous or systemic infections of the yeast Candida albicans. A cDNA encoding part of the 48 kDa antigen has been isolated. From the deduced amino acid sequence of the cDNA clone, the 48 kDa antigen shows homology to the enzyme enolase.

Process versus Product Task Interpretation and Parental Teaching Practice.

Abstract: Research on parental teaching strategies indicates that task interpretation mediates the amount and type of assistance provided by parents for their children. Leont'ev's (1981) three-tiered analytical framework has been employed to examine the relationship between task interpretation and teaching strategies, but task interpretation has been inferred rather than probed directly. Twenty-three preschoolers and their parents (10 mothers and 13 fathers) participated in the present study, the purpose of which was to assess directly parents' task interpretation of a teaching context, and to establish the pattern of relationships between task interpretation and teaching strategies. Task interpretation was coded using the process (learning goals) vs. product (performance goals) distinction suggested in the achievement motivation literature, and teaching strategies were coded in response to children's errors as either direct or indirect. The hypothesis, that process-oriented parents employ indirect error correction strategies and product-oriented parents employ direct error correction strategies, was confirmed. These findings suggest that parents may approach teaching tasks with quite different interpretations, and these interpretations are revealed by, and are consistent with, the teaching strategies they employ.

Implications of research on students’ understanding of electrochemistry for improving science curricula and classroom practice

Abstract: This paper discusses some implications for science teaching that emerged from an investigation of students’ understanding of electrochemistry. Possible reasons for students’ lack of understanding and origins of misconceptions are described, together with suggestions for reducing the incidence of these misconceptions. The compartmentalization of subject knowledge, inadequate prerequisite knowledge, students’ interpretations of language, the use of multiple definitions and models, and the rote application of concepts and algorithms were identified as significant factors contributing to a lack of understanding in electrochemistry. It is proposed that these factors are of wider significance than the study of electrochemistry and have implications for improving science curricula and classroom practice.

‘An Influential Set of Chaps’: The X-Club and Royal Society Politics 1864–85

Abstract: ‘Our’ included not only Hooker and Huxley but their fellow-members of the X-Club. ‘Our time’ had been the 1870s and early 1880s. For a five-year period from November 1873 to November 1878 Hooker had been President of the Society, Huxley one of the Secretaries, and fellow X-Club member, William Spottiswoode, the Treasurer. Hooker was followed in the Presidency by Spottiswoode, and on Spottiswoode's death in 1883 Huxley was elected President. During this period other X-Club members—Edward Frankland, John Tyndall, George Busk, Sir John Lubbock, and Thomas Hirst—were ordinary members of the Council of the Society. As the Table below (p. 60) shows, there were at least three members of the X-Club on the Council of the Royal Society from November 1870 until November 1882. On eight occasions in this period there were four or more X-Club members on the Council. ‘Our time’ came to an end in 1885 when ill-health forced Huxley's retirement after only two years in the Presidency, and G. G. Stokes at last became President.

Segmenting curves into elliptic arcs and straight lines

Abstract: A method is described for segmenting edge data into a combination of straight lines and elliptic arcs. The two-stage process first segments the data into straight line segments. Ellipses are then fitted to the line data. This is much faster than curve fitting directly to pixel data since the lines provide a great reduction in data. Segmentation is performed in the paradigm suggested by D.G. Lowe (1987). A measure of significance is defined that produces a scale-invariant description and allows the replacement of sequences of line segments by ellipses without requiring any thresholds. A method for fitting ellipses to arbitrary curves, essential for this algorithm, has been developed, based on an iterative Kalman filter. This is guaranteed to produce an elliptical fit even though the best conic fit may be a hyperbola or parabola. >

Drinking, the construction of ethnic identity and social process in a Western Australian youth subculture.

Abstract: This paper presents an anthropological analysis of the meaning of drinking for the male members of the Skinhead youth subculture in Perth, Western Australia. Perth Skinheads are an exported and modified form of the original English Skinhead subculture. Using participant observation as the primary research method, the style of drinking is analysed as one of the ways in which the members of this subculture express their English ethnicity and constitutive of the social processes which underpin the subculture. The article also explores the reasons why Perth Skinheads do not conform to a pattern of drinking in rounds held to be characteristic of some working class drinking groups.

GAPEX: A Ground-Based Atmospheric Profiling Experiment.

Abstract: During the week 29 October–4 November 1988, a Ground-based Atmospheric Profiling Experiment (GAPEX) was conducted at Denver Stapleton International Airport. The objective of GAPEX was to acquire and analyze atomspheric-temperature and moisture-profile data from state-of-the-art remote sensors. The sensors included a six-spectral-channel, passive Microwave Profiler (MWP), a passive, infrared High-Resolution Interferometer Sounder (HIS) that provides more than 1500 spectral channels, and an active Radio Acoustic Sounding System (RASS). A Cross-Chain Loran Atmospheric Sounding System (CLASS) was used to provide research-quality in situ thermodynamic observations to verify the accuracy and resolution characteristics of each of the three remote sensors. The first results of the project are presented here to inform the meteorological community of the progress achieved during the GAPEX field phase. These results also serve to demonstrate the excellent prospects for an accurate, continuous thermodynamic ...

An Australian geographical information and modelling system for natural area management

Abstract: A generic geographical information and modelling system (GIMS) has been developed and implemented for 6 million hectares of fire-prone rural land in eastern Australia. Viewed initially as a land management decision support system rather than as a geographical information system (GIS) per se, GIMS provides extensive capabilities for estimating and recording patterns of vegetation and fuel dynamics, analysing the behaviour of fire and its environmental effects, and reviewing strategies for fire control and related issues. The software operates on personal computers via linkage to an indexed, direct access, grid data base. The design, development, implementation, evolution and use of GIMS for land management decision support are described, and tests of the system's ability to predict real-time fire behaviour are provided. The relationship between commercial GIS packages and locally-developed dynamic modelling GIS programs is discussed.

A geochemical and Pb, Sr isotopic study of the evolution of granite-gneisses from the Bastar Craton, Central India

Abstract: Preliminary Pb-Pb and Rb-Sr geochronology of granitic and gneissic rocks from the Sukma area of the Bastar craton, Central India, provides important constraints on crustal evolution, Much of the craton is made up of felsic orthogneisses and younger granitic intrusives, compositionally ranging from tonalite to granite. Pb-Pb isotopic data suggest the presence of ca. 3.0 Ga old gneisses. Younger granitic intrusives have been dated at ca. 2.6 Ga which represents a widespread resetting and/or emplacement event. Comparison of the Pb-Pb and Rb-Sr whole rock ages suggests that the latter were more perturbed after the gneiss-forming or emplacement events. All rock suites show significant geological scatter of isotopic data probably because of sampling on a regional scale, and reflect multi-stage isotopic evolution in a complex terrain. The present isotopic data indicate the presence of Archaean rocks in the Bastar craton and suggest temporal similarity with the oldest crustal rocks in the Singhbhum and Dharwar cratons.

A review of pre-hospital defibrillation by ambulance officers in Perth, Western Australia.

Abstract: Ventricular fibrillation (VF) is the most common presenting rhythm in cardiac arrest occurring outside hospitals. All cases of VF treated with a defibrillation-only protocol by ambulance officers were reviewed. Of the 231 cases entered into the study, 40 (22.7%) patients survived to 28 days after discharge from hospital. The proportion of survivors in this study is similar to that receiving full paramedic services. Further, where time to defribillation is short, the chance of survival improves. The key determinant in survival from VF occurring outside hospital appears to be how rapidly defibrillation can be initiated.

Archaean evolution of the Wongan Hills Greenstone Belt, Yilgarn Craton, Western Australia

Abstract: Ion microprobe and conventional U‐Pb analyses on single zircons from a felsic porphyry from the Wongan Hills Greenstone Belt in the Western Gneiss Terrain of Western Australia define an age of 3010 ± 7 Ma. This is a minimum age for volcanism in the greenstone belt. A sample of gneiss from near the belt contains two populations of zircons with ages of 2997 ± 47 Ma and 2800 ± 9 Ma. The ca 3.0 Ga zircons are interpreted as dating the formation of the granitic parent of the gneiss, and the ca 2.8 Ga zircons are interpreted as dating gneiss formation. This latter event may be an early manifestation of the major 2.65–2.75 Ga granite‐greenstone episode which affected the entire Yilgarn Craton and is expressed at Wongan Hills by the emplacement of post‐tectonic porphyritic granite dated at 2651 ± 4 Ma, and greenschist facies retrogressive metamorphism, dated at 2646 ± 11 Ma by U‐Pb analyses of cogenetic sphene. The present results confirm the significance of ca 3.0 Ga volcanism in the north and western Yilgarn Cr...

Digital signal processing: efficient convolution and Fourier transform techniques

Abstract: An examination of the advanced techniques for efficiently implementing digital convolution in digital signal processing systems, this book covers the two main approaches - direct methods and Fourier transforms. Myers progressively introduces number theory and abstract algebra and his practical approach demonstrates how to use them to develop more efficient algorithms. Exercises reinforce ideas from the text and problems test the reader's understanding of these ideas.

Comparison of 7‐day retrospective and prospective alcohol consumption diaries in a female population in Perth, Western Australia—methodological issues

Abstract: The summer alcohol consumption of women living in metropolitan Perth was measured using both a retrospective and prospective diary. Overall, 1356 women fully completed both the retrospective and prospective alcohol consumption diaries. The prospective diary yielded a significantly higher level (9%) of consumption (p less than 0.00001) compared with the retrospective diary. Although there was no significant difference in the percentage of women drinking at harmful levels (greater than 280 g absolute alcohol per week) between the two diary methods, there did appear to be an important percentage difference (1.9% versus 2.8%) suggesting that the prospective diary did detect a larger percentage of women at risk. This would be both practically and statistically significant in large populations. The heavier the drinker the greater the variability in reported consumption between the two diary weeks. However, it is interesting to note that the direction of the variation depended on which diary was used as the base for classifying women as different types of drinkers. Women who drank at hazardous (140-280 g per week) or harmful (greater than 280 g) levels during the retrospective diary week reported a lower level of consumption during the prospective diary week. Conversely women who drank at hazardous or harmful levels during the prospective diary week reported a lower level of consumption during the retrospective diary week. Possible explanations for these findings are explored and methodological considerations for future studies are discussed.

Kinetics of intestinal calcium absorption in humans measured using stable isotopes and high-precision thermal ionization mass spectrometry.

Abstract: Oral (44Ca: 013-020 mmol) and intravenous (42Ca: 002-0037 mmol) isotopically enriched stable calcium (Ca) tracers were given together with an oral dose of 25 mmol of natural Ca to normal subjects Blood and urine samples were collected up to 24 h after the tracer doses and atom fractions (AFs) of these tracers (relative to natural Ca) were measured by high-precision thermal ionization mass spectrometry (TIMS) The time-dependent fractional rate of oral dose absorbed and true fractional intestinal Ca absorption (alpha) were derived from the Afs by mathematical deconvolution After 6 h, the ratio AF oral tracer/AF intravenous tracer in blood equalled that in urine and did not change thereafter Reproducibility of the combination of chemical precipitation of Ca (from a urine standard) and subsequent TIMS measurements, in nine runs over 13 months, was 12% (coefficient of variation) This was in accord with the within-run reproducibility An estimate of alpha derived from a single blood or urine measurement was 6-10% higher than the reference value obtained by deconvolution This discrepancy could be explained by a correction factor depending, in part, on the elapsed time for peak Ca intestinal absorption rate Instrumentally induced mass fractionation, as well as contributions from radiogenic Ca, had a significant effect on the accuracy and reproducibility of the ratio of AFs of tracers in blood and urine

Normal moveout in anisotropic media

Abstract: Elliptical anisotropy may be considered a more general case of isotropy, in which the medium has been stretched in one direction (Helbig, 1983; Dellinger and Muir, 1988; Verwest, 1989). As a consequence, certain principles and relationships hold for both isotropy, where wavefronts are circular, and elliptical anisotropy, where the wavefronts are circles which have been stretched in one direction (i.e., ellipses); while they may not hold for the general case of anisotropy, where wavefronts have more complex shapes. Examples are the dip moveout (DMO) relation (Uren et al., 1990) and the method of images (Dellinger and Muir, 1988).

Error-rate estimation in two-group discriminant analysis using the linear discriminant function

Abstract: Fisher's linear discriminant function, adapted by Anderson for allocating new observations into one of two existing groups, is considered in this paper. Methods of estimating the misclassification error rates are reviewed and evaluated by Monte Carlo simulations. The investigation is carried out under both ideal (Multivariate Normal data) and non-ideal (Multivariate Binary data) conditions. The assessment is based on the usual mean square error (MSE) criterion and also on a new criterion of optimism. The results show that although there is a common cluster of good estimators for both ideal and non-ideal conditions, the single best estimators vary with respect to the different criteria

Evolution of gypsum karst in the Kirschberg Evaporite Member near Fredericksburg, Texas

Abstract: At the Fredericksburg Gypsum Quarry in Gillespie County near Fredericksburg, Texas the quarry operations expose modern karst features in a 10-m (30 ft) thick gypsum bed that is part of the Cretaceous Kirschberg Evaporite Member. The following sequence of events is documented: 1) Formation of nodular "daisy-head" gypsum. Replacement by gypsum was at first slow but pervasive, with phreatic fluids oozing through the calcium sulfate bed. The main permeability pathways were provided by fractures and the intercrystalline porosity in dolomite films surrounding the calcium sulfate nodules and along thin dolomite beds. Large aligned gypsum crystals nucleated off these flow paths and grew by replacement of the earlier calcium sulfate phase. A change to more active hydrologic conditions modified the rate of secondary gypsum growth, so that the remaining gypsum grew rapidly as a microcrystalline alabastrine form. This adjustment in gypsum type was due to the relative uplift of the bed into more active phreatic conditions closer to the water table. There the bed was subjected to more pronounced temperature changes and increased groundwater flow. 2) Karst Structures and Speleothems. The gypsum bed was introduced into the vadose zone and the process of karstification of the bed began. Dissolution took place forming vertical pipes or caves in the Fredericksburg gypsum bed. Gypsum and calcite speleothems, mainly in the form of popcorn and flowstone, were deposited in the pipes and caves. Extreme dissolution of the gypsum bed produced zones of collapse breccia. This collapse occurred gradually. Locally, the overlying beds were disrupted and folded; regionally, the overlying beds were minimally disrupted by widespread lowering due to complete dissolution and gentle collapse folding. Coarse, botryoidal calcite grew in void spaces in the breccia as it was collapsing. The effects of the vadose regime on the Fredericksburg gypsum bed suggest that the end result of such an unroofed evaporite bed, even if it is never subaerially exposed, is a stratiform layer that has associated with it a breccia consisting of calcite popcorn, boxwork and botryoidal calcite, mixed with fragments of the overlying strata. Little if any evidence of the gypsum remains in the breccia. Textures and structures described herein are used to interpret similar features in other ancient evaporite beds.

The watering down of Australia's health policy on alcohol.

Abstract: The draft National Health Policy on alcohol in Australia, prepared by the Alcohol Sub-Committee of the Ministerial Council on Drug Strategy and presented to that Council in November 1987, is compared to that approved by Ministers at their meeting in March 1989. Attention is directed to those policies and strategies which were substantially altered from the draft document and which, it is argued, represented the policy's most significant recommendations. The role of the alcohol industry in effecting these changes is speculated upon.

A new class of conjugative plasmid in Staphylococcus aureus

Abstract: Summary Plasmid pWBG637, a Staphylococcus aureus conjugative plasmid having no known resistance phenotype, was compared with other conjugative plasmids in S. aureus by restriction endonuclease analysis, incompatibility testing and DNA-DNA hybridisation. It differed from the other conjugative plasmids on all three criteria and thus belongs to a new class of conjugative plasmids.

Bone and soft tissue injuries in post-mortem lumbar spines.

Abstract: A histological study of transverse sections of lumbar facet joints from 36 lumbar spines of subjects dying from serious trauma revealed injuries not visible on standard radiography, and in a high percentage of joints. They include fractures of the superior articular process, central infractions of the subchondral bone plate, and tears of the articular capsule, including the ligamentum flavum. The facet joint injuries in young subjects were almost entirely absent from the facet joints of a comparable group of young subjects with no recent history of major trauma. The injuries resemble some of the 'age changes' seen in older subjects dying non-violent deaths. It is suggested that such injuries may lead to early onset facetal arthritis in survivors of major trauma.

Work-associated back problems: collaborative solutions.

Abstract: Work-associated back problems are a major health issue for which the traditional approaches of manual skills training and worker selection have demonstrated little effect. The common alternative, direct ergonomics intervention, risks work group resentment and non-compliance problems. This paper describes a new ergonomics training approach which changes the role and content of training to facilitate staff and management collaboration.