Showing papers by "University of Wollongong published in 1991"
TL;DR: In this paper, the consequences of split-source and integrated information using electrical engineering and biology instructional materials were evaluated in an industrial training setting, and the results indicated that the materials chosen were unintelligible without mental integration.
Abstract: Cognitive load theory suggests that effective instructional material facilitates learning by directing cognitive resources toward activities that are relevant to learning rather than toward preliminaries to learning. One example of ineffective instruction occurs if learners unnecessarily are required to mentally integrate disparate sources of mutually referring information such as separate text and diagrams. Such split-source information may generate a heavy cognitive load, because material must be mentally integrated before learning can commence. This article reports findings from six experiments testing the consequences of split-source and integrated information using electrical engineering and biology instructional materials. Experiment 1 was designed to compare conventional instructions with integrated instructions over a period of several months in an industrial training setting. The materials chosen were unintelligible without mental integration. Results favored integrated instructions throughout th...
2,512 citations
TL;DR: The relations between insulinemia, insulin resistance, and blood pressure differ among racial groups and may be mediated by mechanisms active in whites, but not in Pima Indians or blacks.
Abstract: Background. Insulin resistance and the concomitant compensatory hyperinsulinemia have been implicated in the pathogenesis of hypertension. However, reports on the relation between insulin and blood pressure are inconsistent. This study was designed to investigate the possibility of racial differences in this relation. Methods. We studied 116 Pima Indians, 53 whites, and 42 blacks who were normotensive and did not have diabetes; the groups were comparable with respect to mean age (29, 30, and 31 years, respectively) and blood pressure (113/70, 111/68, and 113/68 mm Hg, respectively). Insulin resistance was determined by the euglycemic—hyperinsulinemic clamp technique during low-dose (40 mU per square meter of body-surface area per minute) and high-dose (400 mU per square meter per minute) insulin infusions. Results. The Pima Indians had higher fasting plasma insulin concentrations than the whites or blacks (176, 138, and 122 pmol per liter, respectively; P = 0.002) and lower rates of whole-body gl...
433 citations
TL;DR: It is concluded that insulin resistance is associated with a reduced risk of weight gain in nondiabetic Pima Indians.
Abstract: Insulin resistance is commonly associated with obesity and noninsulin-dependent diabetes. Whereas it predicts the development of diabetes, its effect on body weight change is unknown. We measured glucose disposal rates at submaximally- and maximally-stimulating insulin concentrations in 192 nondiabetic Pima Indians and followed their weight change over 3.5 +/- 1.8 y (mean +/- SD). Results: (a) Insulin-resistant subjects gained less weight than insulin-sensitive subjects (3.1 vs. 7.6 kg, P less than 0.0001). (b) The percent weight change per year correlated with glucose disposal at submaximally-(r = 0.19, P less than 0.01) and maximally-stimulating (r = 0.34, P less than 0.0001) insulin concentrations independent of sex, age, initial weight, and 24-h energy expenditure; the correlations were stronger for glucose oxidation than for glucose storage. (c) Weight gain was associated with an increase in insulin resistance more than four times that predicted from the cross-sectional data. We conclude that insulin resistance is associated with a reduced risk of weight gain in nondiabetic Pima Indians.
320 citations
TL;DR: Standard metabolic rate is 7-fold greater in the rat (a typical mammal) than in the bearded dragon, Amphibolurus vitticeps (a reptile with the same body mass and temperature).
Abstract: Standard metabolic rate is 7-fold greater in the rat (a typical mammal) than in the bearded dragon, Amphibolurus vitticeps (a reptile with the same body mass and temperature). Rat hepatocytes respire 4-fold faster than do hepatocytes from the lizard. The inner membrane of isolated rat liver mitochondrial has a proton permeability that is 4-5-fold greater than the proton permeability of the lizard liver mitochondrial membrane per mg of mitochondrial protein. The greater permeability of rat mitochondria is not caused by differences in the surface area of the mitochondrial inner membrane, but differences in the fatty acid composition of the mitochondrial phospholipids may be involved in the permeability differences. Greater proton permeability of the mitochondrial inner membrane may contribute to the greater standard metabolic rate of mammals.
275 citations
TL;DR: The results indicate an age difference in adjustment to fixed orthodontic therapy, which suggests that adolescents are more vulnerable to undesirable psychological effects of treatment.
234 citations
191 citations
TL;DR: Fifty-two women who worked in a telecommunications organisation and a chicken processing factory and had been diagnosed as having RSI were interviewed about their perceptions and experiences of the illness, suggesting that the need to be believed and to establish their integrity dominated their 'pilgrimage'.
172 citations
TL;DR: The synthesis and utilization of electrodes modified with conducting polymers is reviewed in this paper, where various approaches available to produce the required functionality at the electrode surface and the practical considerations to be addressed during synthesis, both in terms of hardware requirements and the chemistry of electropolymerization.
Abstract: The synthesis and utilization of electrodes modified with conducting polymers is reviewed. Specific issues evaluated include the various approaches available to produce the required functionality at the electrode surface and the practical considerations to be addressed during synthesis, both in terms of hardware requirements and the chemistry of electropolymerization. The review concludes with a survey of the many applications of polymer-modified electrodes and includes 112 references.
168 citations
TL;DR: The Biodex dynamometer was found to be both a valid and an accurate research tool; however, caution must be expercised when interpreting and ascribing torques and angular velocities to the limb producing motion.
Abstract: The validity and accuracy of the Biodex dynamometer was investigated under static and dynamic conditions. Static torque and angular position output correlated well with externally derived data (r = 0.998 and r greater than 0.999, respectively). Three subjects performed maximal voluntary knee extensions and flexions at angular velocities from 60 to 450 degrees.s-1. Using linear accelerometry, high speed filming and Biodex software, data were collected for lever arm angular velocity and linear accelerations, and subject generated torque. Analysis of synchronized angular position and velocity changes revealed the dynamometer controlled angular velocity of the lever arm to within 3.5% of the preset value. Small transient velocity overshoots were apparent on reaching the set velocity. High frequency torque artefacts were observed at all test velocities, but most noticeably at the faster speeds, and were associated with lever arm accelerations accompanying directional changes, application of resistive torques by the dynamometer, and limb instability. Isokinematic torques collected from ten subjects (240, 300 and 400 degrees.s-1) identified possible errors associated with reporting knee extension torques at 30 degrees of flexion. As a result of tissue and padding compliance, leg extension angular velocity exceeded lever arm angular velocity over most of the range of motion, while during flexion this compliance meant that knee and lever arm angles were not always identical, particularly at the start of motion. Nevertheless, the Biodex dynamometer was found to be both a valid and an accurate research tool; however, caution must be exercised when interpreting and ascribing torques and angular velocities to the limb producing motion.
165 citations
TL;DR: The paper examines some conceptual issues underlying the narrative analysis method, including the psychosocial functions of narratives, their structure, their embeddedness in interview responses, their linguistic macrofunctions and the concept of core narrative.
139 citations
TL;DR: In this paper, age determinations of alluvial sediments in the tropics are evaluated by comparison with U/Th ages of pedogenic accumulations in the alluvium of the lower Gilbert River, a large fan delta in the wet-dry tropics of northern Queensland, Australia.
TL;DR: In this paper, the authors present a review of models of parking as an integral component of urban transport systems and develop model groupings by relating their main objectives: choice, allocation and interaction models.
TL;DR: It was found that a substantial proportion of the beneficial effect of gemfibrozil was explicable in terms of an increase in the concentration of HDL cholesterol, leading to a widely held view that HDL protects against the development of atherosclerosis.
Abstract: High-density lipoproteins (HDLs) play an important role in the process of reverse cholesterol transport, the pathway by which the cholesterol in extrahepatic tissues is transported through plasma to the liver for recycling or for excretion from the body in bile. The concentration of HDL cholesterol is a powerful inverse predictor of the development of coronary heart disease, leading to a widely held view that HDL protects against the development of atherosclerosis. The mechanism by which HDLs protect is unknown. To date, no studies have been designed specifically to test the proposition that increasing the concentration of HDL cholesterol translates into a reduction in coronary risk. Nevertheless, in a subgroup of the Helsinki Heart Study, it was found that a substantial proportion of the beneficial effect of gemfibrozil was explicable in terms of an increase in the concentration of HDL cholesterol.
TL;DR: In this paper, the electropolymerization mechanism of pyrrole at platinum micro-and macroelectrodes was investigated and it was found that polypyrrole growth was largely the result of the continual precipitation of oligomeric intermediates from solution rather than the sequential addition of polyrole monomers to the polymer chain ends of the deposited polymer.
TL;DR: In this paper, the authors report the development of independent subscales for measurement of logical and intuitive modes of problem solving, based on a sample of 535 respondents, which are interpreted as describing quite accurately the two postulated classifications as advanced above.
Abstract: A number of researchers have provided phenomenological characterization of the logical and intuitive modes of problem solving. In an effort to delve into more detailed analyses of the formal criteria for distinguishing between logical and intuitive modes of problem solving, this paper reports the development of independent subscales for measurement of each of these two modes. Preliminary results from a sample of 535 respondents suggest two factorially independent subscales. These were interpreted as describing quite accurately the two postulated classifications as advanced above. Findings suggest the subscales warrant additional examination in other samples and settings. Practical implications are discussed, including those for researching the area of person-job fit/misfit.
TL;DR: In this paper, it is argued that cooling flows efficiently form dark matter in massive galaxies, which has wider implications for the formation of massive stars in our galaxy, such as brown dwarfs and Jupiter-mass objects.
Abstract: X-ray images and spectra of clusters of galaxies show strong evidence for cooling flows. In many clusters, the hot gas in the core is cooling at rates of ∼ 100M⊙yr−1 and greater. Few traces of the cooled gas have been observed, but it probably forms into low-mass stars (perhaps brown dwarf or even Jupiter-mass objects). X-ray surface-brightness profiles show that the cooling gas is highly inhomogeneous. Overdense gas cools rapidly to form cooled clumps distributed throughout the flow, with little of the gas ever reaching the cluster centre. Cooled and cooling clumps are disrupted because of their motion relative to the remainder of the gas, tending to produce small cooled fragments and, ultimately, low-mass stars. Large molecular clouds, which are the sites of massive star formation in our galaxy, do not occur in the outer parts of cooling flows. There is evidence of larger gas clumps and the formation of more massive stars in the central few kpc of some cooling flows. It is argued that cooling flows efficiently form dark matter. This has wider implications for the formation of dark matter in massive galaxies.
TL;DR: In this paper, the authors identify two characteristics of the MIS, culture content and predictability of outcome, as relevant to the question of when is an early detection of a culture clash worth the effort.
TL;DR: In this paper, an electrosynthetic method for direct incorporation of antibodies into conducing polymeric coatings has been developed and the voltammetric behavior of an anti-human serum albumin (anti-HSA) containing electrode has been considered.
Journal Article•
TL;DR: In areas with a large tidal range, one of the main processes inducing a reversion to saltwater influence is likely to be the rapid extension of tidal-creek systems as discussed by the authors.
Abstract: Low-lying Holocene coastal plains supporting freshwater wetlands are often close to or even below the level reached by the highest tides. The vulnerability of such freshwater systems to saltwater intrusion will increase should the sea level rise as a consequence of global warming. In areas with a large tidal range, one of the main processes inducing a reversion to saltwater influence is likely to be the rapid extension of tidal-creek systems. This is demonstrated with an example from the coastal plains of the Mary River in northern Australia, where tidal-creek systems have extended more than 30 km inland in 50 years, invading freshwater wetlands and destroying associated vegetation over an area of at least 17000 ha. Networks have grown at an exponential rate through a combination of headward extension along main channels and tributary development. Large tidal range, very small elevational differences over the plains, the presence of incompletely infilled paleochannels, and uncontrolled feral buffalo have been major factors contributing to the rapid rate of expansion.
TL;DR: A structured approach is used to generate a fast algorithm to compute two-dimensional discrete cosine transforms (DCT) based on Hou's method and this algorithm is described by logic diagrams which reveal the relationship between the 2-D algorithm and its 1-D counterpart.
Abstract: A structured approach is used to generate a fast algorithm to compute two-dimensional discrete cosine transforms (DCT) based on Hou's method. Hou's algorithm is extended to the 2-D case using an approach presented in both matrix and diagrammatical forms. The matrix approach is discussed, and this forms a basis on which a 2-D fast DCT algorithm is derived. It is shown that this matrix method has a structure similar to that of the 1-D Cooley-Tukey fast Fourier transform (FFT) algorithm. Then the decimation-in-frequency (DIF) 2-D fast DCT algorithm is presented using matrix forms which use the tensor (or Kronecker) product as a construction tool. Finally, the 2-D algorithm is described by logic diagrams which reveal the relationship between the 2-D algorithm and its 1-D counterpart. As an example, the logic diagram of an 8-point*8-point 2-D DCT using the new 2-D DCT algorithm is generated through a simple procedure. >
TL;DR: In this paper, the authors investigated the reduction of hematite fines and magnetite concentrates containing carbon using microwave energy and found that the reduction rate was very rapid under all conditions employed.
Abstract: Reduction of hematite fines and magnetite concentrates containing carbon using microwave energy was investigated. The reduction rate was found to be very rapid under all conditions employed. The nature of the ore mineral and flux (lime and limestone) did not influence the reduction but the nature of carbon had an effect, with charcoal being superior to coke.Microwave reduction is a highly non-isothermal process and bearing this in mind, the effect of temperature on reduction was exponential. Difference between the reduction of identical samples with microwave and conventional heating (1000°C) was remarkable–in favour of microwave heating.
TL;DR: An electrophoretic survey of allozyme variation revealed substantial genetic differentiation within the eastern Australian population of Actinia tenebrosa, and a clear subdivision of the population into northern and southern groups.
Abstract: An electrophoretic survey of allozyme variation revealed substantial genetic differentiation within the eastern Australian population ofActinia tenebrosa. This differentiation appears to reflect the effects of both asexual reproduction and limited gene flow among local populations separated by up to 1050 km. Variation was assessed within groups of 27 to 55 adults sampled between September 1985 and December 1988 collected from small areas of shore within each of 24 local populations. All individuals were collected from stable rock platforms, with the exception of Boulder Bay, where some sea anemones were removed from small mobile boulders. High levels of variability were detected for each of seven enzyme-encoding loci. The patterns of genotypic variation detected imply that local populations are maintained by predominantly asexually generated recruitment. Levels of multi-locus genotypic diversity within samples were consistently less than 50% of the level expected for sexual reproduction with free recombination. This was reflected by the detection of relatively low numbers of multi-locus genotypes and significant departures from expectations for single-locus Hardy-Weinberg equilibria within 17 of the 24 local populations. Standardised genetic variances (F
ST
), calculated from the genotypes of all individual adults were typically much greater than those expected for marine organisms with widely dispersed larvae. The former values were reduced, but were still extremely large when “clonal” genotype frequencies were substituted into the calculation. These data imply that although widely dispersed larvae may be an important source of initial colonists, levels of gene flow among established local populations are low. Furthermore, cluster analysis revealed a clear subdivision of the population into northern and southern groups. However, this subdivision was largely explained by strong clinal variation at a GPI-encoding locus. For this locus, allele frequencies ranged from fixation of the A allele in samples from the 12 most northern sites to near fixation of the alternative B allele in southern samples. Subdivision of the eastern Australian population is consistent with the predicted off-shore movement of the Eastern Australian Current close to the border between Victoria and New South Wales. However, the split into northern and southern regions, as evidenced by the variation forGpi, could reflect patterns of gene flow and/or other factors such as natural selection or the recent patterns of colonisation.
TL;DR: At higher concentrations, glucobrassicin elicited a faster oviposition rate and a stronger visual response to the substrate through associative learning, and is consistent with known glucosinolate profiles of crucifers which show indolyl glucos inolates predominant in foliage.
Abstract: Solutions of glucobrassicin (3-indolylmethyl glucosinolate) purified from foliage and sinigrin (allyl glucosinolate) elicited oviposition by the cabbage butterfly,Pieris rapae, at threshold concentrations as low as 10−6 M. At higher concentrations, glucobrassicin elicited a faster oviposition rate and a stronger visual response to the substrate through associative learning. Solutions of 10−5 M glucobrassicin and 10−2 M sinigrin stimulated equally. Their enzymic hydrolysis products failed to influence oviposition. The markedly greater potency of glucobrassicin is consistent with known glucosinolate profiles of crucifers which show indolyl glucosinolates predominant in foliage.
TL;DR: In this paper, a near-eutectic Al-Si alloy has been investigated for its wear behavior as a function of sliding speed under unlubricated conditions using a pin-on-ring wear-testing machine.
TL;DR: The properties of concretes containing instant-chilled steel slag (I.C.S.) as aggregate are presented in this article, where it is shown that slag possesses good physical and mechanical properties and has sufficient stability for use as a coarse aggregate in concrete.
TL;DR: A detailed analysis of coke oven emissions is reported in this paper, where measurements were made on samples collected at various workplace locations on the oven top and a new type of sampling system was used and is described.
TL;DR: In this article, the authors consider the development of liquid chromatographic technique wherein the imposition of small electrical potentials are used to induce changes in retention, in order to effect a separation.
TL;DR: Tests for specific IgG and seroconversion responses in mice immunized with keyhole limpet haemocyanin (KLH) show that the presence of g-IN on the alum has increased its adjuvanticity 6- to 17-fold, and thus has a synergistic effect.
TL;DR: G gross and microscopic examination of the corallite structures of large coralla, collected from a reef crest biotope, were used to confirm the assignment of these specific names to two electrophoretically distinct groups of corals.
Abstract: Two of the most abundant corals of the Great Barrier Reef Acropora cuneata and Acropora palifera, can be distinguished reliably by conventional taxonomic methods only if large specimens of both species are collected from the same uniform biotope. In this study gross and microscopic examination of the corallite structures of large coralla, collected from a reef crest biotope, were used to confirm the assignment of these specific names to two electrophoretically distinct groups of corals. Identifications based on genetic and morphological data gathered from small fragments of coralla collected from five different sites were in agreement for two sites within which skeletal data were adequate for taxonomic purposes (i.e. one reef crest and one outer lagoon site). However, specimens collected from the other three sites could be identified reliably only by using the electrophoretic data. These results confirm that small fragments from diverse habitats may not be adequate for morphologically based identification. The application of electrophoretic identifications to the results of an earlier electrophoretic survey of 76 sites on 11 reefs revealed that, although A. palifera and A. cuneata frequently co-occur, they have significantly different habitat distributions. Acropora cuneata is more commonly associated with high energy environments such as the reef crest, whereas A. palifera occurs most commonly in the sheltered reef lagoons and on the deeper reef slopes.