Prejudiced attitudes, group norms, and discriminatory behaviour

Most current attitude research focuses on range of non-social attitudinal targets, including health-related and consumer outcomes. In this paper, a program of research that considers the relations among intergroup attitudes, group norms, and behavior will be described. The first study examined the effect of ingroup norms relating to multiculturalism on the extent to wich participants hehaviourally enacted their attitudes. Consistent with social identity theory, attitudebehaviour consistency in relation was influenced by ingroup norms, particularly when national identity was salient. The results of a large scale field study that essential replicated this pattern of results will also be discussed.

Aluminium alloys - their physical and mechanical properties: Grain formation in AlSi7Mg0.35 foundry alloy at low superheat

Hypoeutectic AI-Si alloys represent the most widely used alloy system for cast aluminium applications. This system has a unique behaviour with respect to grain formation where an increase in silicon content results in a transition to larger grain sizes after a minimum at an intermediate concentration. As a result of the already large solute content, grain refinement by solute additions is inefficient and nucleant particles from the common aluminium grain refiners are not as effective as in wrought alloys. However, casting conditions, such as a low pouring temperature, that promote the formation of wall crystals tie. crystals nucleated in the thermally undercooled layer at or next to mould walls) are very effective in yielding a small grain size. This paper presents results of an investigation of the effect of low superheat and mould preheat temperature on grain size. It was found that pouring temperature controls the effectiveness of the wall mechanism while mould preheat has little effect until high preheat temperatures at which a large increase in grain size occurs. The observed changes in grain size are explained in terms of the balance between nucleation rate and survival rate of crystal nuclei resulting from changes in superheat and mould temperature.

Differences in the post-translational modifications of human papillomavirus type 6b major capsid protein expressed from a baculovirus system compared with a vaccinia virus system

Virus-like particles (VLPs) are being currently investigated in vaccines against viral infections in humans. There are different recombinant-protein-expression systems available for obtaining the necessary VLP preparation for vaccination. However, the differences in post-translational modifications of the recombinant proteins obtained and their differences in efficacy in eliciting an anti-viral response in vaccines are not well established. In this study we have compared the posttranslational modifications of human papillomavirus type-6b major capsid protein L1 (HPV 6bL1) expressed using recombinant baculovirus (rBV) in Sf9 (Spodoptera frugiperda) insect cells, with the protein expressed using recombinant vaccinia virus (rVV) in CV-1 kidney epithelial cells, Two-dimensional gel electrophoresis of biosynthetically labelled rBV-expressed HPV 6bL1 showed several post-translationally modified variants of the protein, whereas rVV-expressed HPV 6bL1 showed only a few variants. Phosphorylations were detected at threonine and serine residues for the L1 expressed from rBV compared with phosphorylation at serine residues only for the L1 expressed from rVV. HPV 6bL1 expressed using rBV incorporated [H-3]mannose and [H-3]galactose, whereas HPV 6bL1 expressed using rVV incorporated only [H-3]galactose. We conclude that post-translational modification of recombinant HPV 6bL1 can differ according to the system used for its expression. Since recombinant L1 protein is a potential human-vaccine candidate, the implication of the observed differences in post-translational modifications on immunogenicity of L1 VLPs warrants investigation.

The effects of the Cannabis Expiation Notice System on the prevalence of cannabis use in South Australia: evidence from the National Drug Strategy Household Surveys 1985-95

This study sought to examine the impact of the Cannabis Expiation Notice (CEN) scheme on the prevalence of lifetime and weekly cannabis use in South Australia. Data from five National Drug Strategy Household Surveys between 1985 and 1995 were examined to test for differences in trends in self-reported: (1) lifetime cannabis use; and (2) current weekly cannabis use, after controlling for age and gender, between South Australia and the other states and territories. Between 1985 and 1995, rates of lifetime cannabis use increased in SA from 26% to 36%. There were also significant increases in Victoria (from 26% to 32%), Tasmania (from 21% to 33%) and New South Wales (from 26% to 33%). The increase in South Australia was significantly greater than the average increase throughout the rest of Australia, but the other Australian states differed in their rates of change. Victoria and Tasmania had similar rates of increase to South Australia; New South Wales, Queensland and Western Australia showed lower rates of increase; and the Northern Territory and the Australian Capital Territory had high rates that did not change during the period. There was no statistically significant difference between SA and the rest of Australia in the rate of increase in weekly cannabis use. While there was a greater increase in self- reported lifetime cannabis use in South Australia between 1985 and 1995 than in the average of the other Australian jurisdictions it is unlikely that this increase is due to the CEN system, because similar increases occurred in Tasmania and Victoria (where there was no change in the legal status of cannabis use), and there was no increase in the rate of weekly cannabis use in South Australia over the same period.

Communication and camouflage with the same 'bright' colours in reef fishes

Reef fishes present the observer with the most diverse and stunning assemblage of animal colours anywhere on earth. The functions of some of these colours and their combinations are examined using new non-subjective spectrophotometer ic measurements of the colours of fishes and their habitat. Conclusions reached are as follows: (i) the spectra of colours in high spatial frequency patterns are often well designed to be very conspicuous to a colour vision system at close range but well camouflaged at a distance; (ii) blue and yellow the most frequently used colours in reef fishes, may be good for camouflage or communication depending on the background they are viewed against; and (iii) reef fishes use a combination of colour and behaviour to regulate their conspicuousness and crypsis.

The case for a new system for oversight of research on human subjects

The increasing emphasis on evidence-based clinical practice has thrown into sharp focus multiple deficiencies in current systems of ethical review. This paper argues that a complete overhaul of systems for ethical oversight of studies involving human subjects is now required as developments in medical, epidemiological and genetic research have outstripped existing structures for ethical supervision. It shows that many problems are now evident and concludes that sequential and piecemeal amendments to present arrangements an inadequate to address these. Ar their core present systems of ethical review still rely on the integrity and judgement of individual investigators. One possible alternative is to train and license research investigators, make explicit their responsibilities and have ethics committees devote much more of their time to monitoring research activity in order to detect those infringing the rules.

Foraging and vein-cutting behaviour of Euploea core corinna (W.S. Macleay) (Lepidoptera : Nymphalidae) caterpillars feeding on latex-bearing leaves

Caterpillars of Euploea core corinna (W. S. Macleay) sever leaf veins prior to feeding on their latex-bearing host plants, which restricts the flow of latex at feeding sites. The severing of leaf veins by insects feeding on latex-bearing plants is commonly referred to as 'sabotaging' and is thought to be an evolved response by the insect to counter the negative effects of feeding on latex-rich leaves. Sabotaging behaviour is described for all instars of E. core corinna, with particular attention given to neonates. Vein cutting by neonate E. core corinna caterpillars can occur within 2 h of hatching, with most caterpillars establishing feeding sites within 10 h. Commonly, first instars cut an are-shaped row of leaf side-veins parallel to the leaf margin, but they may also cut the leaf mid-rib in a fashion similar to older instar larvae. From a sample of 50 E. core corinna larvae, representing all instars, we found that the diameters of the veins cut by caterpillars are closely correlated to larval head width (r=0.90). Through manipulative experiments, we demonstrate for the first time that sabotaging behaviour in neonate caterpillars imposes no detectable short-term physiological costs on those caterpillars.

Use of an Arrhenius model to predict rheological behaviour in some Australian honeys

Rheological properties of nine unprocessed unifloral Australian honeys (bloodwood, blue top iron bark, gum top, heath, narrow leafed iron bark, stringy bark, tea tree yapunyah and yellow box) were analysed over a range of temperatures (1-40 degreesC) The temperature effect on the viscosity follow ed an Arrhenius-type relationship and ail honey varieties exhibited Newtonian behaviour. if the Arrhenius equation constants (mu (0) and E-a) for a particular honey are known, the Arrhenius model can be used to calculate the viscosity of these honeys at specific temperatures, negating the need for tedious viscosity determination. (C) 2000 Academic Press.

Evolution of stress deficit and changing rates of seismicity in cellular automaton models of earthquake faults

We investigate the internal dynamics of two cellular automaton models with heterogeneous strength fields and differing nearest neighbour laws. One model is a crack-like automaton, transferring ail stress from a rupture zone to the surroundings. The other automaton is a partial stress drop automaton, transferring only a fraction of the stress within a rupture zone to the surroundings. To study evolution of stress, the mean spectral density. f(k(r)) of a stress deficit held is: examined prior to, and immediately following ruptures in both models. Both models display a power-law relationship between f(k(r)) and spatial wavenumber (k(r)) of the form f(k(r)) similar tok(r)(-beta). In the crack model, the evolution of stress deficit is consistent with cyclic approach to, and retreat from a critical state in which large events occur. The approach to criticality is driven by tectonic loading. Short-range stress transfer in the model does not affect the approach to criticality of broad regions in the model. The evolution of stress deficit in the partial stress drop model is consistent with small fluctuations about a mean state of high stress, behaviour indicative of a self-organised critical system. Despite statistics similar to natural earthquakes these simplified models lack a physical basis. physically motivated models of earthquakes also display dynamical complexity similar to that of a critical point system. Studies of dynamical complexity in physical models of earthquakes may lead to advancement towards a physical theory for earthquakes.

Experimental study of phase equilibria in the PbO-MgO-SiO2 system

Equilibrium phase relations in the PbO-Al2O3-SiO2 system have been investigated experimentally by means of high-temperature equilibration, quenching, and electron probe X-ray microanalysis (EPMA). The system has 21 primary phase fields including three monoxides (PbO, Al2O3, and SiO2), seven binary compounds (Al6Si2O13, PbAl2O4, PbAl12O19, Pb2Al2O5, PbSiO3, Pb2SiO4, and Pb4SiO6), and eleven ternary compounds (PbAl2Si2O8, Pb3Al10SiO20, Pb4Al2Si2O11, Pb4Al4SiO12, Pb4Al4Si3O16, Pb4Al4Si5O20, Pb5Al2Si10O28, Pb6Al2Si6O21, Pb8Al2Si4O19, Pb12Al2Si17O49, and Pb12Al2Si20O55). Three new ternary compounds, Pb4Al4SiO12, Pb4Al4Si5O20, and Pb12Al2Si17O49, were observed and characterized by EPMA. No extensive solid solution in any of the compounds was found in the present study. The liquidus isotherms were experimentally determined in most of the primary phase fields in the temperature range from 923 to 1873 K, and the ternary phase diagram of the PbO-Al2O3-SiO2 System has been constructed.

Simultaneous steady state and dynamic design of process systems using structural indicators

The simultaneous design of the steady-state and dynamic performance of a process has the ability to satisfy much more demanding dynamic performance criteria than the design of dynamics only by the connection of a control system. A method for designing process dynamics based on the use of a linearised systems' eigenvalues has been developed. The eigenvalues are associated with system states using the unit perturbation spectral resolution (UPSR), characterising the dynamics of each state. The design method uses a homotopy approach to determine a final design which satisfies both steady-state and dynamic performance criteria. A highly interacting single stage forced circulation evaporator system, including control loops, was designed by this method with the goal of reducing the time taken for the liquid composition to reach steady-state. Initially the system was successfully redesigned to speed up the eigenvalue associated with the liquid composition state, but this did not result in an improved startup performance. Further analysis showed that the integral action of the composition controller was the source of the limiting eigenvalue. Design changes made to speed up this eigenvalue did result in an improved startup performance. The proposed approach provides a structured way to address the design-control interface, giving significant insight into the dynamic behaviour of the system such that a systematic design or redesign of an existing system can be undertaken with confidence.

A dual catalyst bed system for the elimination of hydrogen from CO2 feed gas in urea synthesis

A dual catalyst bed system (Au/Fe2O3 + Pt-Pd/Al2O3) for eliminating hydrogen from the CO2 feed gas in urea synthesis is found to be far superior to commercially available and patented catalysts in catalytic activity. At relatively low temperatures, hydrogen is eliminated and coexistent CO is also oxidized completely to useful CO2. This can avoid effectively the accidental explosion of hydrogen-oxygen-ammonia mixed gases, thus ensuring the safety of urea synthesis.

Wave-induced seepage flux into anisotropic seabeds

Considerable effort has been devoted to quantifying the wave-induced soil response in a porous seabed in the last few decades. Most previous investigations have focused on the analysis of pore pressure and effective stresses within isotropic sediments, despite strong evidence of anisotropic soil behaviour reported in the literature. Furthermore, the seepage flux, which is important in the context of contaminant transport, has not been examined. In this paper, we focus on water wave-driven seepage in anisotropic marine sediments of finite thickness. The numerical results predict that the effects of hydraulic anisotropy and anisotropic soil behaviour on the wave-driven seepage in marine sediment are significant. Copyright (C) 2001 John Wiley & Sons, Ltd.