The clay-size fraction of CI chondrites Alais and Orgueil : an AEM study

CI chondrites are used pervasively in the meteorite literature as a cosmochemical reference point for bulk compositions[1], isotope analyses[2] and, within certain models of meteorite evolution, as an important component of an alteration sequence within the carbonaceous chondrite subset[3]. More recently, the chemical variablity of CI chondrite matrices (which comprise >80% of the meteorite), has been cited in discussions about the "chondritic" nature of spectroscopic data from P/comet Halley missions[4] and of chemical data from related materials such as interplanetary dust particles[5]. Most CI chondrites have been studied as bulk samples(e.g. major and trace element abundances)and considerable effort has also been focussed on accessory phases such as magnetites, olivine, sulphates and carbonates [6-8]. A number of early studies showed that the primary constituents of CI matrices are layer silicates and the most definitive structural study on powdered samples identified two minerals: montmorillonite and serpentine[9]. In many cases, as with the study by Bass[9],the relative scarcity of most CI chondrites restricts such bulk analyses to the Orgueil meteorite. The electron microprobe/SEM has been used on petrographic sections to more precisely define the "bulk" composition of at least four CI matrices[3], and as recently summarised by McSween[3], these data define a compositional trend quite different to that obtained for CM chondrite matrices. These "defocussed-beam" microprobe analyses average major element compositions over matrix regions ~lOOµm in diameter and provide only an approximation to silicate mineral composition(s) because their grain sizes are much less than the diameter of the beam. In order to (a) more precisely define the major element compositions of individual mineral grains within CI matrices, and (b)complement previous TEM studies [11,12], we have undertaken an analytical electron microscopy (AEM) study of Alais and Orgueil matrices.

Front interactions in a three-component system

The three-component reaction-diffusion system introduced in [C. P. Schenk et al., Phys. Rev. Lett., 78 (1997), pp. 3781–3784] has become a paradigm model in pattern formation. It exhibits a rich variety of dynamics of fronts, pulses, and spots. The front and pulse interactions range in type from weak, in which the localized structures interact only through their exponentially small tails, to strong interactions, in which they annihilate or collide and in which all components are far from equilibrium in the domains between the localized structures. Intermediate to these two extremes sits the semistrong interaction regime, in which the activator component of the front is near equilibrium in the intervals between adjacent fronts but both inhibitor components are far from equilibrium there, and hence their concentration profiles drive the front evolution. In this paper, we focus on dynamically evolving N-front solutions in the semistrong regime. The primary result is use of a renormalization group method to rigorously derive the system of N coupled ODEs that governs the positions of the fronts. The operators associated with the linearization about the N-front solutions have N small eigenvalues, and the N-front solutions may be decomposed into a component in the space spanned by the associated eigenfunctions and a component projected onto the complement of this space. This decomposition is carried out iteratively at a sequence of times. The former projections yield the ODEs for the front positions, while the latter projections are associated with remainders that we show stay small in a suitable norm during each iteration of the renormalization group method. Our results also help extend the application of the renormalization group method from the weak interaction regime for which it was initially developed to the semistrong interaction regime. The second set of results that we present is a detailed analysis of this system of ODEs, providing a classification of the possible front interactions in the cases of $N=1,2,3,4$, as well as how front solutions interact with the stationary pulse solutions studied earlier in [A. Doelman, P. van Heijster, and T. J. Kaper, J. Dynam. Differential Equations, 21 (2009), pp. 73–115; P. van Heijster, A. Doelman, and T. J. Kaper, Phys. D, 237 (2008), pp. 3335–3368]. Moreover, we present some results on the general case of N-front interactions.

Coexistence of stable spots and fronts in a three-component FitzHugh-Nagumo system

We investigate regions of bistability between different travelling and stationary structures in a planar singularly-perturbed three-component reaction-diffusion system that arises in the context of gas discharge systems. In previous work, we delineated the existence and stabil-ity regions of stationary localized spots in this system. Here, we complement this analysis by establishing the stability regions of planar travelling fronts and stationary stripes. Taken together, these results imply that stable fronts and spots can coexist in three-component systems. Numerical simulations indicate that the stable fronts never move towards stable spots but instead move away from them.

Embedding information and communication technologies in the early childhood classroom

New technologies and the pace of change in modern society mean changes for classroom teaching and learning. Information and communication technologies (ICTs) feature in everyday life and provide ample opportunities for enhancing classroom programs. This article outlines how ICTs complement curriculum implementation in one year two classroom. It suggests practical strategies demonstrating how teachers can make ICTs work for them and progressively teach children how to make ICTs work for them.

The cost of carbon : capital market effects of the proposed emission trading scheme (ETS)

In March 2008, the Australian Government announced its intention to introduce a national Emissions Trading Scheme (ETS), now expected to start in 2015. This impending development provides an ideal setting to investigate the impact an ETS in Australia will have on the market valuation of Australian Securities Exchange (ASX) firms. This is the first empirical study into the pricing effects of the ETS in Australia. Primarily, we hypothesize that firm value will be negatively related to a firm's carbon intensity profile. That is, there will be a greater impact on firm value for high carbon emitters in the period prior (2007) to the introduction of the ETS, whether for reasons relating to the existence of unbooked liabilities associated with future compliance and/or abatement costs, or for reasons relating to reduced future earnings. Using a sample of 58 Australian listed firms (constrained by the current availability of emissions data) which comprise larger, more profitable and less risky listed Australian firms, we first undertake an event study focusing on five distinct information events argued to impact the probability of the proposed ETS being enacted. Here, we find direct evidence that the capital market is indeed pricing the proposed ETS. Second, using a modified version of the Ohlson (1995) valuation model, we undertake a valuation analysis designed not only to complement the event study results, but more importantly to provide insights into the capital market's assessment of the magnitude of the economic impact of the proposed ETS as reflected in market capitalization. Here, our results show that the market assesses the most carbon intensive sample firms a market value decrement relative to other sample firms of between 7% and 10% of market capitalization. Further, based on the carbon emission profile of the sample firms we imply a ‘future carbon permit price’ of between AUD$17 per tonne and AUD$26 per tonne of carbon dioxide emitted. This study is more precise than industry reports, which set a carbon price of between AUD$15 to AUD$74 per tonne.

Brisbane : creative city, cinema city?

Brisbane stands at the cross roads of many major economic, social and cultural opportunities as it positions itself as a cosmopolitan, globally networked metropolis of the twenty-first century. In order to link and leverage the existing screen industries infrastructure into Brisbane’s creative city’s plans, the paper argues for a re-think of the existing policy frameworks that support Australian screen culture and the national screen industries. Instead of remaining premised on a separation of these two activities the paper argues for a greater recognition of the overlaps occurring in both production and consumption of screen content. By acknowledging the impact new media technologies and social behaviours and the way they are re-shaping media consumption and media production practices, film and media policy could be better positioned to complement the emerging creative city policy frameworks that are being fostered in a city like Brisbane. The paper argues that reconsideration of the culture/industry separation that characterizes contemporary policy settings underpinning Australian media and screen production assistance would not only assist in identifying crucial synergies within a creative city policy it would also invigorate policy settings for the screen industries and enable them to connect more efficiently to a shifting film and media production and consumption landscape.

Non-acute shoulder imaging: Which projections do we really need?

While Magentic Resonance Imaging and Ultrasound are used extensively for non-acute shoulder imaging, plain images are regularly required as a first investigation. This paper presents a snapshot of the diversity of projections performed and a review of the current evidence of the most appropriate projections. The projections recommended are suitable as a first investigation, and also to complement more advanced imaging.

Virtual birding : extending an environmental pastime into the virtual world for citizen science

This paper investigates engaging experienced birders, as volunteer citizen scientists, to analyze large recorded audio datasets gathered through environmental acoustic monitoring. Although audio data is straightforward to gather, automated analysis remains a challenging task; the existing expertise, local knowledge and motivation of the birder community can complement computational approaches and provide distinct benefits. We explored both the culture and practice of birders, and paradigms for interacting with recorded audio data. A variety of candidate design elements were tested with birders. This study contributes an understanding of how virtual interactions and practices can be developed to complement existing practices of experienced birders in the physical world. In so doing this study contributes a new approach to engagement in e-science. Whereas most citizen science projects task lay participants with discrete real world or artificial activities, sometimes using extrinsic motivators, this approach builds on existing intrinsically satisfying practices.

Designing the information architecture of governmental one-stop portals : on the application and analysis of card sorting

The latest paradigm shift in government, termed Transformational Government, puts the citizen in the centre of attention. Including citizens in the design of online one-stop portals can help governmental organisations to become more customer focussed. This study describes the initial efforts of an Australian state government to develop an information architecture to structure the content of their future one-stop portal. Hereby, card sorting exercises have been conducted and analysed, utilising contemporary approaches found in academic and non-scientific literature. This paper describes the findings of the card sorting exercises in this particular case and discusses the suitability of the applied approaches in general. These are distinguished into non-statistical, statistical, and hybrid approaches. Thus, on the one hand, this paper contributes to academia by describing the application of different card sorting approaches and discussing their strengths and weaknesses. On the other hand, this paper contributes to practice by explaining the approach that has been taken by the authors’ research partner in order to develop a customer-focussed governmental one-stop portal. Thus, they provide decision support for practitioners with regard to different analysis methods that can be used to complement recent approaches in Transformational Government.

What is a good project manager? Reconceptualizing the “do” : an Aristotelian perspective

In Social Science (Organization Studies, Economics, Management Science, Strategy, International Relations, Political Science…) the quest for addressing the question “what is a good practitioner?” has been around for centuries, with the underlying assumptions that good practitioners should lead organizations to higher levels of performance. Hence to ask “what is a good “captain”?” is not a new question, we should add! (e.g. Tsoukas & Cummings, 1997, p. 670; Söderlund, 2004, p. 190). This interrogation leads to consider problems such as the relations between dichotomies Theory and Practice, rigor and relevance of research, ways of knowing and knowledge forms. On the one hand we face the “Enlightenment” assumptions underlying modern positivist Social science, grounded in “unity-of-science dream of transforming and reducing all kinds of knowledge to one basic form and level” and cause-effects relationships (Eikeland, 2012, p. 20), and on the other, the postmodern interpretivist proposal, and its “tendency to make all kinds of knowing equivalent” (Eikeland, 2012, p. 20). In the project management space, this aims at addressing one of the fundamental problems in the field: projects still do not deliver their expected benefits and promises and therefore the socio-economical good (Hodgson & Cicmil, 2007; Bredillet, 2010, Lalonde et al., 2012). The Cartesian tradition supporting projects research and practice for the last 60 years (Bredillet, 2010, p. 4) has led to the lack of relevance to practice of the current conceptual base of project management, despite the sum of research, development of standards, best & good practices and the related development of project management bodies of knowledge (Packendorff, 1995, p. 319-323; Cicmil & Hodgson, 2006, p. 2–6, Hodgson & Cicmil, 2007, p. 436–7; Winter et al., 2006, p. 638). Referring to both Hodgson (2002) and Giddens (1993), we could say that “those who expect a “social-scientific Newton” to revolutionize this young field “are not only waiting for a train that will not arrive, but are in the wrong station altogether” (Hodgson, 2002, p. 809; Giddens, 1993, p. 18). While, in the postmodern stream mainly rooted in the “practice turn” (e.g. Hällgren & Lindahl, 2012), the shift from methodological individualism to social viscosity and the advocated pluralism lead to reinforce the “functional stupidity” (Alvesson & Spicer, 2012, p. 1194) this postmodern stream aims at overcoming. We suggest here that addressing the question “what is a good PM?” requires a philosophy of practice perspective to complement the “usual” philosophy of science perspective. The questioning of the modern Cartesian tradition mirrors a similar one made within Social science (Say, 1964; Koontz, 1961, 1980; Menger, 1985; Warry, 1992; Rothbard, 1997a; Tsoukas & Cummings, 1997; Flyvbjerg, 2001; Boisot & McKelvey, 2010), calling for new thinking. In order to get outside the rationalist ‘box’, Toulmin (1990, p. 11), along with Tsoukas & Cummings (1997, p. 655), suggests a possible path, summarizing the thoughts of many authors: “It can cling to the discredited research program of the purely theoretical (i.e. “modern”) philosophy, which will end up by driving it out of business: it can look for new and less exclusively theoretical ways of working, and develop the methods needed for a more practical (“post-modern”) agenda; or it can return to its pre-17th century traditions, and try to recover the lost (“pre-modern”) topics that were side-tracked by Descartes, but can be usefully taken up for the future” (Toulmin, 1990, p. 11). Thus, paradoxically and interestingly, in their quest for the so-called post-modernism, many authors build on “pre-modern” philosophies such as the Aristotelian one (e.g. MacIntyre, 1985, 2007; Tsoukas & Cummings, 1997; Flyvbjerg, 2001; Blomquist et al., 2010; Lalonde et al., 2012). It is perhaps because the post-modern stream emphasizes a dialogic process restricted to reliance on voice and textual representation, it limits the meaning of communicative praxis, and weaking the practice because it turns away attention from more fundamental issues associated with problem-definition and knowledge-for-use in action (Tedlock, 1983, p. 332–4; Schrag, 1986, p. 30, 46–7; Warry, 1992, p. 157). Eikeland suggests that the Aristotelian “gnoseology allows for reconsidering and reintegrating ways of knowing: traditional, practical, tacit, emotional, experiential, intuitive, etc., marginalised and considered insufficient by modernist [and post-modernist] thinking” (Eikeland, 2012, p. 20—21). By contrast with the modernist one-dimensional thinking and relativist and pluralistic post-modernism, we suggest, in a turn to an Aristotelian pre-modern lens, to re-conceptualise (“re” involving here a “re”-turn to pre-modern thinking) the “do” and to shift the perspective from what a good PM is (philosophy of science lens) to what a good PM does (philosophy of practice lens) (Aristotle, 1926a). As Tsoukas & Cummings put it: “In the Aristotelian tradition to call something good is to make a factual statement. To ask, for example, ’what is a good captain’?’ is not to come up with a list of attributes that good captains share (as modem contingency theorists would have it), but to point out the things that those who are recognized as good captains do.” (Tsoukas & Cummings, 1997, p. 670) Thus, this conversation offers a dialogue and deliberation about a central question: What does a good project manager do? The conversation is organized around a critic of the underlying assumptions supporting the modern, post-modern and pre-modern relations to ways of knowing, forms of knowledge and “practice”.

Researching 'what works' in early intervention and prevention of homelessness : From systematic reviews to collaborative inquiry

Mechanisms of intervention and the contexts they are used in interact in complex ways. This helps explain why we can’t overgeneralize about what works in respect of models of service designed to prevent or respond to homelessness. This said there are some key messages from the totality of evidence that has been accumulated to date. First homelessness would be a lot easier to prevent for first or subsequent episodes if adequate and appropriate (developmentally/ culturally) housing was available. Second (and often dependent on the first) timely support of a particular character ‘works’ both in a preventive sense and in periods when people experience ongoing challenges which may render them vulnerable to further homelessness. This paper reflects on some of the critical features of how we can generate and use evidence, and how these complement each other in important ways.

Scanning the genome for essential hypertension loci

1. Essential hypertension occurs in people with an underlying genetic predisposition who subject themselves to adverse environmental influences. The number of genes involved is unknown, as is the extent to which each contributes to final blood pressure and the severity of the disease. 2. In the past, studies of potential candidate genes have been performed by association (case-control) analysis of unrelated individuals or linkage (pedigree or sibpair) analysis of families. These studies have resulted in several positive findings but, as one may expect, also an enormous number of negative results. 3. In order to uncover the major genetic loci for essential hypertension, it is proposed that scanning the genome systematically in 100- 200 affected sibships should prove successful. 4. This involves genotyping sets of hypertensive sibships to determine their complement of several hundred microsatellite polymorphisms. Those that are highly informative, by having a high heterozygosity, are most suitable. Also, the markers need to be spaced sufficiently evenly across the genome so as to ensure adequate coverage. 5. Tests are performed to determine increased segregation of alleles of each marker with hypertension. The analytical tools involve specialized statistical programs that can detect such differences. Non- parametric multipoint analysis is an appropriate approach. 6. In this way, loci for essential hypertension are beginning to emerge.

Rank minimization across appearance and shape for AAM ensemble fitting

Active Appearance Models (AAMs) employ a paradigm of inverting a synthesis model of how an object can vary in terms of shape and appearance. As a result, the ability of AAMs to register an unseen object image is intrinsically linked to two factors. First, how well the synthesis model can reconstruct the object image. Second, the degrees of freedom in the model. Fewer degrees of freedom yield a higher likelihood of good fitting performance. In this paper we look at how these seemingly contrasting factors can complement one another for the problem of AAM fitting of an ensemble of images stemming from a constrained set (e.g. an ensemble of face images of the same person).

A parametric analysis technique for design of fuel cell and hybrid-electric vehicles

This paper presents a new simplified parametric analysis technique for the design of fuel cell and hybrid-electric vehicles. The technique utilizes a comprehensive set of ∼30 parameters to fully characterize the vehicle platform, powertrain components, vehicle performance requirements and driving conditions. It is best applied to the sizing of powertrain components and prediction of energy consumption in a vehicle. This new parametric technique makes a good complement to existing vehicle simulation software packages and therefore represents a potentially valuable tool for the hybrid vehicle designer.

Controlling whole blood activation and resultant clot properties on various material surfaces : a possible therapeutic approach for enhancing bone healing

Injured bone initiates the healing process by forming a blood clot at the damaged site. However, in severe damage, synthetic bone implants are used to provide structural integrity and restore the healing process. The implant unavoidably comes into direct contact with whole blood, leading to a blood clot formation on its surface. Despite this, most research in bone tissue engineering virtually ignores the important role of a blood clot in supporting healing. Surface chemistry of a biomaterial is a crucial property in mediating blood-biomaterials interactions, and hence the formation of the resultant blood clot. Surfaces presenting mixtures of functional groups carboxyl (–COOH) and methyl (–CH3) have been shown to enhance platelet response and coagulation activation, leading to the formation of fibrin fibres. In addition, it has been shown that varying the compositions of these functional groups and the length of alkyl groups further modulate the immune complement response. In this study, we hypothesised that a biomaterial surface with mixture of –COOH/–CH3(methyl), –CH2CH3 (ethyl) or –(CH2)3CH3 (butyl) groups at different ratios would modulate blood coagulation and complement activation, and eventually tailor the structural and functional properties of the blood clot formed on the surface, which subsequently impacts new bone formation. Firstly, we synthesised a series of materials composed of acrylic acid (AA), and methyl (MMA), ethyl (EMA) or butyl methacrylates (BMA) at different ratios and coated on the inner surfaces of incubation vials. Our surface analysis showed that the amount of –COOH groups on the surface coatings was lower than the ratios of AA prepared in the materials even though the surface content of –COOH groups increased with increasing in AA ratios. It was indicated that the surface hydrophobicity increased with increasing alkyl chain length: –CH 3 > –CH2CH3 > –(CH2)3CH3, and decreased with increasing –COOH groups. No significant differences in surface hydrophobicity was found on surfaces with –CH3 and –CH2CH3 groups in the presence of –COOH groups. The material coating was as smooth as uncoated glass and without any major flaws. The average roughness of material-coated surface (3.99 ± 0.54 nm) was slightly higher than that of uncoated glass surface (2.22 ± 0.29 nm). However, no significant differences in surface average roughness was found among surfaces with the same functionalities at different –COOH ratios nor among surfaces with different alkyl groups but the same –COOH ratios. These suggested that the surface functional groups and their compositions had a combined effect on modulating surface hydrophobicity but not surface roughness. The second part of our study was to investigate the effect of surface functional groups and their compositions on blood cascade activation and structural properties of the formed clots. It was found that surfaces with –COOH/–(CH2)3CH3 induced a faster coagulation activation than those with –COOH/–CH3 and –CH2CH3, regardless of the –COOH ratios. An increase in –COOH ratios on –COOH/–CH3 and –CH2CH3 surfaces decreased the rate of activation. Moreover, all material-coated surfaces markedly reduced the complement activation compared to uncoated glass surfaces, and the pattern of complement activation was entirely similar to that of surface-induced coagulation, suggesting there is an interaction between two cascades. The clots formed on material-coated surfaces had thicker fibrin with a tighter network at the exterior when compared to uncoated glass surfaces. Compared to the clot exteriors, thicker fibrins with a loose network were found in clot interiors. Coated surfaces resulted in more rigid clots with a significantly slower fibrinolysis after 1 h of lysis when compared to uncoated glass surfaces. Significant differences in fibrinolysis after 1 h of lysis among clots on material-coated surfaces correlated well with the differences in fibrin thickness and density at clot exterior. In addition, more growth factors were released during clot formation than during clot lysis. From an intact clot, there was a correlation between the amount of PDGF-AB release and fibrin density. Highest amount of PDGF-AB was released from clots formed on surfaces with 40% –COOH/60% –CH 3 (i.e. 65MMA). During clot lysis, the release of PDGF-AB also correlated with the fibrinolytic rate while the release of TGF-â1 was influenced by the fibrin thickness. This suggested that different clot structures led to different release profiles of growth factors in clot intact and degrading stages. We further validated whether the clots formed on material-coatings provide the microenvironment for improved bone healing by using a rabbit femoral defect model. In this pilot study, the implantation of clots formed on 65MMA coatings significantly increased new bone formation with enhanced chondrogenesis, osteoblasts activity and vascularisation, but decreased inflammatory macrophage number at the defects after 4 weeks when compared to commercial bone grafts ChronOSTM â-TCP granules. Empty defects were observed when blood clot formation was inhibited. In summary, our study demonstrated that surface functional groups and their relative ratios on material coatings synergistically modulate activation of blood cascades, resultant fibrin architecture, rigidity, susceptibility to fibrinolysis as well as growth factor release of the formed clots, which ultimately alter the healing microenvironment of injured bones.