995 resultados para 163-989A


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Raman and infrared spectra of two well-defined fluellite samples, Al2(PO4)F2(OH)�7H2O, from the Krásno near Horní Slavkov (Czech Republic) and Kapunda, South Australia (Australia) were studied and tentatively interpreted. Observed bands were assigned to the stretching and bending vibrations of phosphate tetrahedra, aluminum oxide/hydroxide/fluoride octahedra, water molecules and hydroxyl ions. Approximate O–H���O hydrogen bond lengths were inferred from the Raman and infrared spectra.

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In this article, we study the security of the IDEA block cipher when it is used in various simple-length or double-length hashing modes. Even though this cipher is still considered as secure, we show that one should avoid its use as internal primitive for block cipher based hashing. In particular, we are able to generate instantaneously free-start collisions for most modes, and even semi-free-start collisions, pseudo-preimages or hash collisions in practical complexity. This work shows a practical example of the gap that exists between secret-key and known or chosen-key security for block ciphers. Moreover, we also settle the 20-year-old standing open question concerning the security of the Abreast-DM and Tandem-DM double-length compression functions, originally invented to be instantiated with IDEA. Our attacks have been verified experimentally and work even for strengthened versions of IDEA with any number of rounds.

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Vom Oderhochwasser über Hurricane Sandy bis zum Tsunami und Reaktormeltdown an der japanischen Ostküste: die letzten Jahre waren leider reich an Naturkatastrophen und anderen Krisensituationen, welche Hunderttausende von Menschen betroffen haben. Abgesehen davon, daß viele dieser Krisen auch die ersten Auswirkungen des Klimawandels greifbar gemacht haben, verdeutlichen sie auch eine andere, ebenfalls nicht unwichtige Form des Wandels: die graduelle Umgestaltung der Medienlandschaft, in der herkömmliche Massenmedien vermehrt durch soziale Medien wie Facebook oder Twitter ergänzt und teilweise vielleicht sogar ersetzt werden.

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In this article, we investigate eight and nine year old girls’ school and home use of the popular game Minecraft and the ways in which the girls ‘bring themselves into being’ through talk and digital production in the social spaces of the classroom and within the game’s multiplayer online world. This work was conducted as part of a broader digital games in education project involving primary and secondary school-aged students in Australia and focuses specifically on data collected from an all-girls primary school in Brisbane. We investigate the processes of identity construction that occur as the girls undertake practices of curatorship (Potter, 2012) to display their knowledge of Minecraft through discussion of the game, both ‘in world’ and in face-to-face interactions, and as they assemble resources within and around the game to design, build and display their creations and share stories about their game play. The article begins with a consideration of recent scholarship focussing on children, learning and digital culture and literacy practices before explaining how Minecraft is, in many ways, an exemplary instance of a digital game that promotes and enables complex practices of digital participation. We then introduce the concepts of performativity and recognition (Butler 1990, 2004, 2005) which, we argue, provide productive ways to theorise identity work within affinity groups. The article then outlines some background to the research project and our methodology before providing analysis of the data in the second half of the article. We conclude by outlining the implications of our investigation for the conceptualisation of learning spaces as affinity groups and for considering digital participation as curatorship.

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Chronic leg ulcers are costly to manage for health service providers. Although evidence-based care leads to improved healing rates and reduced costs, a significant evidence-practice gap is known to exist. Lack of access to specialist skills in wound care is one reason suggested for this gap. The aim of this study was to model the change to total costs and health outcomes under two versions of health services for patients with leg ulcers: routine health services for community-living patients; and care provided by specialist wound clinics. Mean weekly treatment and health services costs were estimated from participants’ data (n=70) for the twelve months prior to their entry to a study specialist wound clinic, and prospectively for 24 weeks after entry. For the retrospective phase mean weekly costs of care were $AU130.30 (SD $12.64) and these fell to $AU53.32 (SD $6.47) for the prospective phase. Analysis at a population level suggests if 10,000 individuals receive 12 weeks of specialist evidence-based care, the cost savings are likely to be AU$9,238,800. Significant savings could be made by the adoption of evidence-based care such as that provided by the community and outpatient specialist wound clinics in this study.

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Cancers of the brain and central nervous system account for 1.6% of new cancers and 1.8% of cancer deaths globally. The highest rates of all developed nations are observed in Australia and New Zealand. There are known complexities associated with dose measurement of very small radiation fields. Here, 3D dosimetric verification of treatments for small intracranial tumours using gel dosimetry was investigated.

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It is well established that there are inherent difficulties involved in communicating across cultural boundaries. When these difficulties are encountered within the justice system the innocent can be convicted and witnesses undermined. A large amount of research has been undertaken regarding the implications of miscommunication within the courtroom but far less has been carried out on language and interactions between police and Indigenous Australians. It is necessary that officers of the law be made aware of linguistic issues to ensure they conduct their investigations in a fair, effective and therefore ethical manner. This paper draws on Cultural Schema Theory to illustrate how this could be achieved. The justice system is reliant upon the skills and knowledge of the police, therefore, this paper highlights the need for research to focus on the linguistic and non‐verbal differences between Australian Aboriginal English and Australian Standard English in order to develop techniques to facilitate effective communication.

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The assumptions underlying the Probability Ranking Principle (PRP) have led to a number of alternative approaches that cater or compensate for the PRP’s limitations. All alternatives deviate from the PRP by incorporating dependencies. This results in a re-ranking that promotes or demotes documents depending upon their relationship with the documents that have been already ranked. In this paper, we compare and contrast the behaviour of state-of-the-art ranking strategies and principles. To do so, we tease out analytical relationships between the ranking approaches and we investigate the document kinematics to visualise the effects of the different approaches on document ranking.

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Recognising that charitable behaviour can be motivated by public recognition and emotional satisfaction, not-for-profit organisations have developed strategies that leverage self-interest over altruism by facilitating individuals to donate conspicuously. Initially developed as novel marketing programs to increase donation income, such conspicuous tokens of recognition are being recognised as important value propositions to nurture donor relationships. Despite this, there is little empirical evidence that identifies when donations can be increased through conspicuous recognition. Furthermore, social media’s growing popularity for self-expression, as well as the increasing use of technology in donor relationship management strategies, makes an examination of virtual conspicuous tokens of recognition in relation to what value donors seek particularly insightful. Therefore, this research examined the impact of experiential donor value and virtual conspicuous tokens of recognition on blood donor intentions. Using online survey data from 186 Australian blood donors, results show that in fact emotional value is a stronger predictor of intentions to donate blood than altruistic value, while social value is the strongest predictor of intentions if provided with recognition. Clear linkages between dimensions of donor value (altruistic, emotional and social) and conspicuous donation behaviour (CDB) were identified. The findings provide valuable insights into the use of conspicuous donation tokens of recognition on social media, and contribute to our understanding into the under-researched areas of donor value and CDB.

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The statutory arrangements for the management of natural resources in Australia confer powers of decision-making upon government agencies and, at the same time, restrict how these powers are to be exercised by reference either to stated criteria or in some instances to the public interest. These restrictions perform different functions according to their structure, form and language: for example they may be in the form of jurisdictional, deliberative or purposive rules. This article reviews how the offshore resources legislation of the Commonwealth and some examples of the onshore resources legislation of Queensland address the functions performed by the public interest in determining whether there is compliance with the principle of the rule of law.

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The aim of this paper is to aid researchers in undertaking action research within industry with a particular focus on the study of design-led innovation. This paper presents the research design of a case study shaped to solve real world problems concerning a major Australian Airport Corporation by bridging the chasm between academia and industry. The researcher’s role is one of design-innovation catalyst, facilitating the integration of design as a new strategic capability and innovation approach within an organisation’s fabric. A discussion of the researcher experience within industry will provide evidence on the challenges facing such a research role, with strategies for overcoming these barriers presented. Based on the authors’ experience as a researcher within industry and reflection within practice, a project progression model for action research is presented to enable the improved management of industry based research.

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Background: Malaria rapid diagnostic tests (RDTs) are increasingly used by remote health personnel with minimal training in laboratory techniques. RDTs must, therefore, be as simple, safe and reliable as possible. Transfer of blood from the patient to the RDT is critical to safety and accuracy, and poses a significant challenge to many users. Blood transfer devices were evaluated for accuracy and precision of volume transferred, safety and ease of use, to identify the most appropriate devices for use with RDTs in routine clinical care. Methods: Five devices, a loop, straw-pipette, calibrated pipette, glass capillary tube, and a new inverted cup device, were evaluated in Nigeria, the Philippines and Uganda. The 227 participating health workers used each device to transfer blood from a simulated finger-prick site to filter paper. For each transfer, the number of attempts required to collect and deposit blood and any spilling of blood during transfer were recorded. Perceptions of ease of use and safety of each device were recorded for each participant. Blood volume transferred was calculated from the area of blood spots deposited on filter paper. Results: The overall mean volumes transferred by devices differed significantly from the target volume of 5 microliters (p < 0.001). The inverted cup (4.6 microliters) most closely approximated the target volume. The glass capillary was excluded from volume analysis as the estimation method used is not compatible with this device. The calibrated pipette accounted for the largest proportion of blood exposures (23/225, 10%); exposures ranged from 2% to 6% for the other four devices. The inverted cup was considered easiest to use in blood collection (206/ 226, 91%); the straw-pipette and calibrated pipette were rated lowest (143/225 [64%] and 135/225 [60%] respectively). Overall, the inverted cup was the most preferred device (72%, 163/227), followed by the loop (61%, 138/227). Conclusions: The performance of blood transfer devices varied in this evaluation of accuracy, blood safety, ease of use, and user preference. The inverted cup design achieved the highest overall performance, while the loop also performed well. These findings have relevance for any point-of-care diagnostics that require blood sampling.

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The therapeutic effects induced by serotonin-selective reuptake inhibitor (SSRI) antidepressants are initially triggered by blocking the serotonin transporter and rely on long-term adaptations of pre- and post-synaptic receptors. We show here that long-term behavioral and neurogenic SSRI effects are abolished after either genetic or pharmacological inactivation of 5-HT(2B) receptors. Conversely, direct agonist stimulation of 5-HT(2B) receptors induces an SSRI-like response in behavioral and neurogenic assays. Moreover, the observation that (i) this receptor is expressed by raphe serotonergic neurons, (ii) the SSRI-induced increase in hippocampal extracellular serotonin concentration is strongly reduced in the absence of functional 5-HT(2B) receptors and (iii) a selective 5-HT(2B) agonist mimics SSRI responses, supports a positive regulation of serotonergic neurons by 5-HT(2B) receptors. The 5-HT(2B) receptor appears, therefore, to positively modulate serotonergic activity and to be required for the therapeutic actions of SSRIs. Consequently, the 5-HT(2B) receptor should be considered as a new tractable target in the combat against depression.