White sharks exploit the sun during predatory approaches

There is no conclusive evidence of any nonhuman animal using the sun as part of its predation strategy. Here, we show that the world's largest predatory fish-the white shark (Carcharodon carcharias)-exploits the sun when approaching baits by positioning the sun directly behind them. On sunny days, sharks reversed their direction of approach along an east-west axis from morning to afternoon but had uniformly distributed approach directions during overcast conditions. These results show that white sharks have sufficient behavioral flexibility to exploit fluctuating environmental features when predating. This sun-tracking predation strategy has a number of potential functional roles, including improvement of prey detection, avoidance of retinal overstimulation, and predator concealment.

Flow analysis based on a pulsed flow of solution: theory, instrumentation and applications

The increased demands placed on solution propulsion by programmed flow systems, such as sequential injection analysis, lab-on-value technology, bead injection and multi-commutation, has highlighted the inability of many conventional pumps to generate a smooth, consistent flow. A number of researchers have examined ways to overcome the inadvertent, uncontrolled pulsation caused by the mechanical action of peristaltic pumps. In contrast, we have developed instruments that exploit the characteristics of a reproducible pulsed flow of solution. In this paper, we discuss our instrumental approaches and some applications that have benefited from the use of a reproducible pulsed flow rather than the traditional linear flow approach. To place our approach in the context of the continuously developing field of flow analysis, an overview of other programmed flow systems is also presented.

Blind source separation based on phase and frequency redundancy of cyclostationary signals

This paper presents a new method for blind source separation by exploiting phase and frequency redundancy of cyclostationary signals in a complementary way. It requires a weaker separation condition than those methods which only exploit the phase diversity or the frequency diversity of the source signals. The separation criterion is to diagonalize a polynomial matrix whose coefficient matrices consist of the correlation and cyclic correlation matrices, at time delay .TAU. = 0, of multiple measurements. An algorithm is proposed to perform the blind source separation. Computer simulation results illustrate the performance of the new algorithm in comparison with the existing ones.

The role of recrystallization and coarsening in the formation of ultrafine grained steels through thermomechanical processing.

There is now considerable interest in the development of ultrafine grained steels with an average grain size of the order of 1µm. One of the methods with currently the greatest industrial interest is by dynamic strain induced transformation from austenite to ferrite. This involves deformation below the
equilibrium transformation temperature so that transformation occurs during the deformation. However, large strains are required to completely transform the microstructure during deformation. It is potentially possible to activate transformation during deformation then continue transformation
during subsequent cooling. It is shown that there are two critical strains: the first is where dynamic transformation commences and the second is the minimum strain for a fully ultrafine final microstructure after cooling to room temperature. The deformation and potential role of dynamic
recrystallization of the dynamically formed ferrite is also considered. Overall it is clear that for full industrial exploitation there is a need to understand and exploit the competing issues of nucleation, growth and recrystallization of the ferrite by both dynamic and static processes.

Using digital data and bibliometric analysis for researching doctoral education

As more digital data become publicly available new opportunities for researchers in education are arising. Researchers may be unaware of the existence and usefulness of such data even though these are freely available. In this article the use of one such source of information is described and its potential for research into research education discussed. We sought to exploit the research potential of the existing, yet dispersed, collection of online Australian thesis records to inform their research into the development of the PhD in Australia. Having created a searchable and reliable database from the available records, bibliometric analyses enabled us to map knowledge production and research capability in institutional and disciplinary settings from 1949 to 2003 as indicated by PhD theses. This is in contrast to the more familiar use of data based on student load or completion rates, and complements that data by focusing on research output as opposed to student throughput.

MMSE precoder for unitary space–time codes in correlated time-varying channels

This letter addresses the problem of the design of a precoder for multiple transmit antenna communication systems with spatially and temporally correlated fading channels. By using the asymptotic (high signal-to-noise ratio) mean-square error of the channel estimates, the letter derives a precoder for unitary space-time codes that can exploit the spatiotemporal correlation in the time-varying fading channels. Simulation results illustrate that significant performance gains can be achieved by using the new precoder.

Effect of transformation volume contraction on the toughness of superelastic shape memory alloys

Shape memory alloys (SMAs) exhibit two very important properties: shape memory phenomenon and superelastic deformation due to intrinsic thermoelastic martensitic transformation. To fully exploit the potential of SMAs in developing functional structures or smart structures in mechanical and biomechanical engineering, it is important to understand and quantify the failure mechanisms of SMAs. This paper presents a theoretical study of the effect of phase-transformation-induced volume contraction on the fracture properties of superelastic SMAs. A simple model is employed to account for the forward and reverse phase transformation with pure volume change, which is then applied to numerically study the transformation field near the tip of a tensile crack. The results reveal that during steady-state crack propagation, the transformation zone extends ahead of the crack tip due to forward transformation while partial reverse transformation occurs in the wake. Furthermore, as a result of the volume contraction associated with the austenite-to-martensite transformation, the induced stress-intensity factor is positive. This is in stark contrast with the negative stress-intensity factor achieved in zirconia ceramics, which undergoes volume expansion during phase transformation. The reverse transformation has been found to have a negligible effect on the induced stress-intensity factor. An important implication of the present results is that the phase transformation with volume contraction in SMAs tends to reduce their fracture resistance and increase the brittleness.

Pieces of silver : examples of the economic impact and management of the silver gull (Larus novaehollandiae) in Melbourne, Australia

Like a number of gull species, the silver gull Larus novaehollandiae has expanded its population in response to human food subsidy. The major anthropogenic food source is food waste at rubbish tips. Other sources of human food waste are also exploited. Many problems result from the activities of these birds, including human health and safety, economic impacts, and effects on the conservation of other species. My study examines aspects of the economic impacts of the silver gull on the human community of the Greater Melbourne Area comprising approximately 4065 km2 (1569 square miles). My data collection method involves identifying sites where problems have been experienced and completing questionnaires during face to face interviews with the managers of those sites. Data collected at this early stage of the study demonstrate that there are significant, quantifiable economic impacts associated with the superabundance of the silver gull in this area. Other impacts, such as reduced amenity and potential health hazards are equally real but more difficult to quantify. Costs include damage to structures and products, damage prevention measures, and loss of production. Information about the costs of these problems will be presented to the relevant landfill management authorities to encourage them to consider alternative means of disposing of putrescible waste, rather than by open landfill disposal, because even current best practice management of open landfill sites (rubbish tips) provides ample opportunity for silver gulls and certain other bird species to exploit this food source. Controlling access by the silver gull to food at rubbish tips would be an important first step in managing the population of this species.

More than just a transaction: conceptualising industry-based networks for virtual trading communities

This paper addresses the questions of why failure in industry-based networks has been so persistent and whether it is possible to avoid failure and achieve success in internet based markets [iMarketplaces]. A better explanation of implementation failures is important for both improved empirical outcomes and theory building. We construct a theoretical framework based on Bijker’s technology frame (1995) and a contextualization typology developed by Nowotny, Scott and Gibbons (2001). The framework helps us understand how industry-based networks function, why they fail and how we can apply the framework to assist better empirical outcomes. In this paper we apply our framework to Food Connect Australia, a vertically integrated marketplace, representative of the first wave of B2B markets. Sponsors of these iMarketplaces were quick to see and exploit the opportunities online access offered to bring together large numbers of buyers and sellers in new ways. However a lack of understanding of firstly, what represented true value in these networks and secondly, how to achieve buy-in at sustainable levels, meant that many of these first wave sites failed. Application of our framework reveals why there has been a radical shift from the trading role originally envisioned for these sites to the information hub model of the iMarketplace that industry is now being urged to adopt (Berryman and Heck, 2001).

Missionaries, music and method - dissemination of tonic sol-fa in Asia-Pacific countries during the nineteenth century

The Tonic Sol-fa method of teaching choral singing and its system of music notation was developed in England by John Curwen and propagated throughout the British Isles as a means of both enhancing Christian worship and achieving social reform. Tonic Sol-fa may be identified as an entirely foreign musical practice introduced to indigenous people in many British colonies and in other overseas countries during the nineteenth century as an instrument of Christian evangelism as well as of European cultural imposition. Nevertheless, indigenous communities were introduced to other aspects of European musical culture including a choral repertoire consisting of four-part hymnody and masterworks by Handel, Bach, Mozart, etc which sometimes resulted in the emergence of a school of indigenous composers writing in Tonic Sol-fa notation and using the tonal harmonic style. The result has been that in several countries-such as South Africa and Fiji for example-Tonic Sol-fa has been so fully assimilated into the ethnic culture that it has been "indigenized" and may now be said to represent a significant exogenous aspect of the musical culture in these countries.

Tonic Sol-fa was most commonly introduced to countries in the Asia-Pacific Region -as in Africa - by Christian missionaries who sought to exploit the attraction of hymns, particularly when sung in four-part harmony, as a means of evangelizing indigenous people who frequently regarded this aspect of missionary activity as a form of "magic". In particular, the Tonic Sol-fa method and notation gained a significant foothold in what were referred to as the South Sea Islands--especially in Fiji where today, the Fijian Hymn Book (1985 edition) is notated exclusively in Tonic Sol-fa. The vast majority of the Fijians are literate in Tonic Sol-fa notation and congregational singing in four parts is the norm in Fijian churches.

This paper will draw on data from nineteenth century journal sources, particularly The Tonic Sol-fa Reporter (1853-1888) and The Musical Herald (1889-1920), and will document the introduction and dissemination of Tonic Sol-fa in several Asia-Pacific countries where, unlike Australia and New Zealand, the indigenous population has maintained its own cultural and demographic predominance. Countries to be considered will include India, China (including Hong Kong), and Pacific Island nations. There will also be a consideration of the contemporary usage and applications of Tonic Sol-fa in the region, with specific reference to Fiji. It will be argued that countries where Tonic Sol-fa notation has become the norm should resist any external pressure to transfer to the standard staff notation merely for the sake of conformity. In the case of Fiji, almost universal music literacy has been achieved through Tonic Sol-fa and this should be recognized as an enviable social and cultural asset.

Precoder design for multi-antenna systems with temporally and spatially correlated fading channels

This paper addresses the problem of the design of a precoder for multiple transmit antenna communication systems with spatially and temporally correlated fading channels. Using the theories of matrix differential calculus, the paper derives a precoder for unitary space-time codes that can exploit the spatio-temporal correlation in the time-varying fading channels. The design criterion is based on minimizing the mean square error of the channel estimates. Computer simulation results show that a significant performance gain can be achieved by using the designed precoder.

Differential encoding technique for multi-antenna systems with correlated Rayleigh fading channels

Differential space-time modulation (DSTM) techniques developed for multi-antenna systems allow the receiver to detect the transmitted signal without the knowledge of the fading channels. It can be viewed as an extension of differential phase-shift keying (DPSK) in single antenna systems. In this paper, we derived the pairwise error probability upper bound of differential space-time coded systems with spatially correlated Rayleigh fading channels. Based on the performance analysis, we develop a novel DSTM scheme which can exploit the spatial correlation in the fading channels. It is found that by carefully designing the initial transmitted signal matrix, the performance of the differential space-time coded systems can be significantly improved.

A preliminary meta-analysis of SME ebusiness journal publications: current trends and future research opportunities moving beyond adoption factor studies

Previous meta-analyses of SME-eBusiness journal research focuses on analysing adoption factors, pre-2000 articles and a small number of journals. This paper departs from this research by analysing 100 articles published between 2003 and 2006 in 41 journals on the basis of the research approaches employed, countries and eBusiness technologies studied, and research objectives focused upon. The paper presents preliminary insights into current major research trends based on this analysis, such as the predominant focus on adoption factor by many studies. It also identifies future research opportunities, and proposes a research agenda which aims to progress SME-eBusiness research beyond adoption factor studies by outlining research objectives to help SMEs overcome barriers and exploit drivers.

Ontogeny of diving behaviour in the Australian sea lion: trials of adolescence in a late bloomer

1.Foraging behaviours of the Australian sea lion (Neophoca cinerea) reflect an animal working hard to exploit benthic habitats. Lactating females demonstrate almost continuous diving, maximize bottom time, exhibit elevated field metabolism and frequently exceed their calculated aerobic dive limit. Given that larger animals have disproportionately greater diving capabilities, we wanted to examine how pups and juveniles forage successfully.
2.Time/depth recorders were deployed on pups, juveniles and adult females at Seal Bay Conservation Park, Kangaroo Island, South Australia. Ten different mother/pup pairs were equipped at three stages of development (6, 15 and 23 months) to record the diving behaviours of 51 (nine instruments failed) animals.
3. Dive depth and duration increased with age. However, development was slow. At 6 months, pups demonstrated minimal diving activity and the mean depth for 23-month-old juveniles was only 44 ± 4 m, or 62% of adult mean depth.
4. Although pups and juveniles did not reach adult depths or durations, dive records for young sea lions indicate benthic diving with mean bottom times (2·0 ± 0·2 min) similar to those of females (2·1 ± 0·2 min). This was accomplished by spending higher proportions of each dive and total time at sea on or near the bottom than adults. Immature sea lions also spent a higher percentage of time at sea diving.
5. Juveniles may have to work harder because they are weaned before reaching full diving capability. For benthic foragers, reduced diving ability limits available foraging habitat. Furthermore, as juveniles appear to operate close to their physiological maximum, they would have a difficult time increasing foraging effort in response to reductions in prey. Although benthic prey are less influenced by seasonal fluctuations and oceanographic perturbations than epipelagic prey, demersal fishery trawls may impact juvenile survival by disrupting habitat and removing larger size classes of prey. These issues may be an important factor as to why the Australian sea lion population is currently at risk.