948 resultados para Modern science
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Generally, the magnitude of pollutant emissions from diesel engines is ultimately coupled to the structure of fuel molecules. The presence of oxygen, level of unsaturation and the carbon chain length of respective molecules influence the combustion chemistry. It is speculated that increased oxygen content in the fuel may lead to the increased oxidative potential (Stevanovic, S. 2013). Also, upon the exposure to UV and ozone in the atmosphere, the chemical composition of the exhaust is changed. The presence of an oxidant and UV is triggering the cascade of photochemical reactions as well as the partitioning of semi-volatile compounds between the gas and particle phase. To gain an insight into the relationship between the molecular structures of the esters, their volatile organic content and the potential toxicity of diesel exhaust particulate matter, measurements were conducted on a modern common rail diesel engine. This research also investigates the contribution of atmospheric conditions on the transfer of semi-volatile fraction of diesel exhaust from the gas phase to the particle phase and the extent to which semi-volatile compounds (SVOCs) are related to the oxidative potential, expressed through the concentration of reactive oxygen species (ROS) (Stevanovic, S. 2013)...
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The purpose of the Reimagining Learning Spaces project was to conduct an empirical study that would result in findings to inform the design and use of physical school facilities and examine the ways in which these constructions influence pedagogy. The study focused on newly-established school libraries in Queensland, many of which had been established with funding from the Federal Government’s Building the Education Revolution economic stimulus program. To explore the field, the study sought multiple perspectives that included those of school students as well as teacher-librarians and other key school staff, addressing the following focus question: - How does the physical environment of school libraries influence pedagogic practices and learning outcomes? Further research questions that guided the inquiry included: - What are the implications for teacher-librarians when transitioning into a new library learning space? - How do members of the school community (principals, teachers, teacher-librarians and students) experience the creation of a new school library learning space? - How do school students imagine the design and use of engaging library learning spaces? An extensive review explored Australian and international literature based on the research questions, focused on the following major areas: • School library renewal: trends in reimagining the place of libraries in virtual and real space • School libraries as learning spaces: the expanded role of school libraries in whole-school pedagogical support. • The role of teacher-librarians in new times • Built environments and the implications for learning • Learners and learning in newly established spaces • Learning space design: perspectives, research and principles • Pedagogical principles and voices of experience • Transitions to newly created learning spaces Approach Using an innovative qualitative research design, Reimagining Learning Spaces investigated learner and teacher perspectives across three intersecting domains exploring: - Imagined spaces: learners’ imaginative concepts of learning within engaging learning environments; - Emerging spaces: experiences of teacher-librarians in the transition into new spaces for learning, and - Established spaces: learners’ and teachers’ perceptions of ways in which the physical environment influences and shapes pedagogy. Seven schools that had recently benefitted from the BER program became the research sites at which data were collected from teacher-librarians, teachers, school leaders and students. With this range of participants, an appropriately diverse set of data collection tools was developed, including video interviews, drawings, and focus groups. Evocative narrative case studies (Simons 2009) were developed from the data, representing the voices of users of learning spaces. Key findings The study’s findings are presented in this report and complemented by an array of visual materials on the project web site http:// The report includes: • a set of seven cases studies that reveal nuanced experiences of designing and creating school libraries, based on the narrative of key stakeholders (teacher-librarians, teachers, students and principals) • thematic discussion of student imaginings of their ideal school library, based on drawings and narrative of students at the seven case study schools • critical analysis of the case study and student imaginings, focusing on implications for (re)designing school learning spaces and pedagogy, and responding to the study’s overarching research question - .17 recommendations to support: designing, transitioning and reimagining pedagogy; leadership; and policy development
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Policy makers increasingly recognise that an educated workforce with a high proportion of Science, Technology, Engineering and Mathematics (STEM) graduates is a pre-requisite to a knowledge-based, innovative economy. Over the past ten years, the proportion of first university degrees awarded in Australia in STEM fields is below the global average and continues to decrease from 22.2% in 2002 to 18.8% in 2010 [1]. These trends are mirrored by declines between 20% and 30% in the proportions of high school students enrolled in science or maths. These trends are not unique to Australia but their impact is of concern throughout the policy-making community. To redress these demographic trends, QUT embarked upon a long-term investment strategy to integrate education and research into the physical and virtual infrastructure of the campus, recognising that expectations of students change as rapidly as technology and learning practices change. To implement this strategy, physical infrastructure refurbishment/re-building is accompanied by upgraded technologies not only for learning but also for research. QUT’s vision for its city-based campuses is to create vibrant and attractive places to learn and research and to link strongly to the wider surrounding community. Over a five year period, physical infrastructure at the Gardens Point campus was substantially reconfigured in two key stages: (a) a >$50m refurbishment of heritage-listed buildings to encompass public, retail and social spaces, learning and teaching “test beds” and research laboratories and (b) destruction of five buildings to be replaced by a $230m, >40,000m2 Science and Engineering Centre designed to accommodate retail, recreation, services, education and research in an integrated, coordinated precinct. This landmark project is characterised by (i) self-evident, collaborative spaces for learning, research and social engagement, (ii) sustainable building practices and sustainable ongoing operation and; (iii) dynamic and mobile re-configuration of spaces or staffing to meet demand. Innovative spaces allow for transformative, cohort-driven learning and the collaborative use of space to prosecute joint class projects. Research laboratories are aggregated, centralised and “on display” to the public, students and staff. A major visualisation space – the largest multi-touch, multi-user facility constructed to date – is a centrepiece feature that focuses on demonstrating scientific and engineering principles or science oriented scenes at large scale (e.g. the Great Barrier Reef). Content on this visualisation facility is integrated with the regional school curricula and supports an in-house schools program for student and teacher engagement. Researchers are accommodated in a combined open-plan and office floor-space (80% open plan) to encourage interdisciplinary engagement and cross-fertilisation of skills, ideas and projects. This combination of spaces re-invigorates the on-campus experience, extends educational engagement across all ages and rapidly enhances research collaboration.
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Information accountability is seen as a mode of usage control on the Web. Due to its many dimensions, information accountability has been expressed in various ways by computer scientists to address security and privacy in recent times. Information accountability is focused on how users participate in a system and the underlying policies that govern the participation. Healthcare is a domain in which the principles of information accountability can be utilised well. Modern health information systems are Internet based and the discipline is called eHealth. In this paper, we identify and discuss the goals of accountability systems and present the principles of information accountability. We characterise those principles in eHealth and discuss them contextually. We identify the current impediments to eHealth in terms of information privacy issues of eHealth consumers together with information usage requirements of healthcare providers and show how information accountability can be used in a healthcare context to address these needs. The challenges of implementing information accountability in eHealth are also discussed in terms of our efforts thus far.
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The production of adequate agricultural outputs to support the growing human population places great demands on agriculture, especially in light of ever-greater restrictions on input resources. Sorghum is a drought-adapted cereal capable of reliable production where other cereals fail, and thus represents a good candidate to address food security as agricultural inputs of water and arable land grow scarce. A long-standing issue with sorghum grain is that it has an inherently lower digestibility. Here we show that a low-frequency allele type in the starch metabolic gene, pullulanase, is associated with increased digestibility, regardless of genotypic background. We also provide evidence that the beneficial allele type is not associated with deleterious pleiotropic effects in the modern field environment. We argue that increasing the digestibility of an adapted crop is a viable way forward towards addressing food security while maximizing water and land-use efficiency.
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High-precision analysis using accelerator mass spectrometry (AMS) was performed upon known-age Holocene and modern, pre-bomb coral samples to generate a marine reservoir age correction value (ΔR) for the Houtman-Abrolhos Archipelago (28.7°S, 113.8°E) off the Western Australian coast. The mean ΔR value calculated for the Abrolhos Islands, 54 ± 30 yr (1σ) agrees well with regional ΔR values for Leeuwin Current source waters (N-NW Australia-Java) of 60 ± 38. The Abrolhos Islands show little variation with ΔR values of the northwestern and north Australian coast, underlining the dominance of the more equilibrated western Pacific-derived waters of the Leeuwin Current over local upwelling. The Abrolhos Islands ΔR values have remained stable over the last 2896 yr cal BP, being also attributed to the Leeuwin Current and the El Niño Southern Oscillation (ENSO) signal during this period. Expected future trends will be a strengthening of the teleconnection of the Abrolhos Islands to the climatic patterns of the equatorial Pacific via enhanced ENSO and global warming activity strengthening the Leeuwin Current. The possible effect upon the trend of future ΔR values may be to maintain similar values and an increase in stability. However, warming trends of global climate change may cause increasing dissimilarity of ΔR values due to the effects of increasing heat stress upon lower-latitude coral communities.
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Streamciphers are common cryptographic algorithms used to protect the confidentiality of frame-based communications like mobile phone conversations and Internet traffic. Streamciphers are ideal cryptographic algorithms to encrypt these types of traffic as they have the potential to encrypt them quickly and securely, and have low error propagation. The main objective of this thesis is to determine whether structural features of keystream generators affect the security provided by stream ciphers.These structural features pertain to the state-update and output functions used in keystream generators. Using linear sequences as keystream to encrypt messages is known to be insecure. Modern keystream generators use nonlinear sequences as keystream.The nonlinearity can be introduced through a keystream generator's state-update function, output function, or both. The first contribution of this thesis relates to nonlinear sequences produced by the well-known Trivium stream cipher. Trivium is one of the stream ciphers selected in a final portfolio resulting from a multi-year project in Europe called the ecrypt project. Trivium's structural simplicity makes it a popular cipher to cryptanalyse, but to date, there are no attacks in the public literature which are faster than exhaustive keysearch. Algebraic analyses are performed on the Trivium stream cipher, which uses a nonlinear state-update and linear output function to produce keystream. Two algebraic investigations are performed: an examination of the sliding property in the initialisation process and algebraic analyses of Trivium-like streamciphers using a combination of the algebraic techniques previously applied separately by Berbain et al. and Raddum. For certain iterations of Trivium's state-update function, we examine the sets of slid pairs, looking particularly to form chains of slid pairs. No chains exist for a small number of iterations.This has implications for the period of keystreams produced by Trivium. Secondly, using our combination of the methods of Berbain et al. and Raddum, we analysed Trivium-like ciphers and improved on previous on previous analysis with regards to forming systems of equations on these ciphers. Using these new systems of equations, we were able to successfully recover the initial state of Bivium-A.The attack complexity for Bivium-B and Trivium were, however, worse than exhaustive keysearch. We also show that the selection of stages which are used as input to the output function and the size of registers which are used in the construction of the system of equations affect the success of the attack. The second contribution of this thesis is the examination of state convergence. State convergence is an undesirable characteristic in keystream generators for stream ciphers, as it implies that the effective session key size of the stream cipher is smaller than the designers intended. We identify methods which can be used to detect state convergence. As a case study, theMixer streamcipher, which uses nonlinear state-update and output functions to produce keystream, is analysed. Mixer is found to suffer from state convergence as the state-update function used in its initialisation process is not one-to-one. A discussion of several other streamciphers which are known to suffer from state convergence is given. From our analysis of these stream ciphers, three mechanisms which can cause state convergence are identified.The effect state convergence can have on stream cipher cryptanalysis is examined. We show that state convergence can have a positive effect if the goal of the attacker is to recover the initial state of the keystream generator. The third contribution of this thesis is the examination of the distributions of bit patterns in the sequences produced by nonlinear filter generators (NLFGs) and linearly filtered nonlinear feedback shift registers. We show that the selection of stages used as input to a keystream generator's output function can affect the distribution of bit patterns in sequences produced by these keystreamgenerators, and that the effect differs for nonlinear filter generators and linearly filtered nonlinear feedback shift registers. In the case of NLFGs, the keystream sequences produced when the output functions take inputs from consecutive register stages are less uniform than sequences produced by NLFGs whose output functions take inputs from unevenly spaced register stages. The opposite is true for keystream sequences produced by linearly filtered nonlinear feedback shift registers.
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This study seeks to bring the discipline of exercise science into the discussion of Quantitative Skills (QS) in Science. The author’s experiences of providing learning support to students and working with educators in the field are described, demonstrating the difficulty of encouraging students to address their skills deficit. A survey of students’ perceptions of their own QS and of that required for their course, demonstrates the difficulties faced by students who do not have the prescribed assumed knowledge for the course. Limited results from academics suggest that their perceptions of students’ QS deficits are even more dire than those of the under-prepared students.
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This study is about young adolescents' engagement in learning science. The middle years of schooling are critical in the development of students' interest and engagement with learning. Successful school experiences enhance dispositions towards a career related to those experiences. Poor experiences lead to negative attitudes and rejection of certain career pathways. At a time when students are becoming more aware, more independent and focused on peer relationships and social status, the high school environment in some circumstances offers more a content-centred curriculum that is less personally relevant to their lives than the social melee surrounding them. Science education can further exacerbate the situation by presenting abstract concepts that have limited contextual relevance and a seemingly difficult vocabulary that further alienates adolescents from the curriculum. In an attempt to reverse a perceived growing disinterest by students to science (Goodrum, Druhan & Abbs, 2011), a study was initiated based on a student-centred unit designed to enhance and sustain adolescent engagement in science. The premise of the study was that adolescent students are more responsive toward learning if they are given an appropriate learning environment that helps connect their learning with life beyond the school. The purpose of this study was to examine the experiences of young adolescents with the aim of transforming school learning in science into meaningful experiences that connected with their lives. Two areas were specifically canvassed and subsumed within the study to strengthen the design base. One area that of the middle schooling ideology, offered specific pedagogical approaches and a philosophical framework that could provide opportunities for reform. The other area, the construct of scientific literacy (OECD, 2007) as defined by Holbrook and Rannikmae, (2009) appeared to provide a sense of purpose for students to aim toward and value for becoming active citizens. The study reported here is a self-reflection of a teacher/researcher exploring practice and challenging existing approaches to the teaching of science in the middle years of schooling. The case study approach (Yin, 2003) was adopted to guide the design of the study. Over a 6-month period, the researcher, an experienced secondary-science teacher, designed, implemented and documented a range of student-centred pedagogical practices with a Year-7 secondary science class. Data for this case study included video recordings, journals, interviews and surveys of students. Both quantitative and qualitative data sources were employed in a partially mixed methods research approach (Leech & Onwuegbuzie, 2009) dominated by qualitative data with the concurrent collection of quantitative data to corroborate interpretations as a means of analysing and developing a model of the dynamic learning environment. The findings from the case study identified five propositions that became the basis for a model of a student-centred learning environment that was able to sustain student participation and thus engagement in science. The study suggested that adolescent student engagement can be promoted and sustained by providing a classroom climate that encourages and strengthens social interaction. Engagement in science can be enhanced by presenting developmentally appropriate challenges that require rigorous exploration of contextually relevant learning environments; supporting students to develop connections with a curriculum that aligns with their own experiences. By setting an environment empathetic to adolescent needs and understandings, students were able to actively explore phenomena collaboratively through developmentally appropriate experiences. A significant outcome of this study was the transformative experiences of an insider, the teacher as researcher, whose reflections provide an authentic model for reforming pedagogy. The model and theory presented became an adjunct to my repertoire for science teaching in the middle years of schooling. The study was rewarding in that it helped address a void in my understanding of middle years of schooling by prompting me to re-think the notion of adolescence in the context of the science classroom. This study is timely given the report "The Status and Quality of Year 11 and 12 Science in Australian Schools" (Goodrum, Druhan & Abbs, 2011) and national curricular changes that are being proposed for science (ACARA, 2009).
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Background Several lines of evidence suggests that transcription factors are involved in the pathogenesis of Multiple Sclerosis (MS) but a complete mapping the whole network has been elusive. One of the reasons is that there are several clinical subtypes of MS and transcription factors which may be involved in one subtype may not be in others. We investigated the possibility that this network could be mapped using microarray technologies and modern bioinformatics methods on a dataset from whole blood in 99 untreated MS patients (36 Relapse Remitting MS, 43 Primary Progressive MS, and 20 Secondary Progressive MS) and 45 age-matched healthy controls, Methodology/Principal Findings We have used two different analytical methodologies: a differential expression analysis and a differential co-expression analysis, which have converged on a significant number of regulatory motifs that seem to be statistically overrepresented in genes which are either differentially expressed (or differentially co-expressed) in cases and controls (e.g. V$KROX_Q6, p-value < 3.31E-6; V$CREBP1_Q2, p-value < 9.93E-6, V$YY1_02, p-value < 1.65E-5). Conclusions/significance: Our analysis uncovered a network of transcription factors that potentially dysregulate several genes in MS or one or more of its disease subtypes. Analysing the published literature we have found that these transcription factors are involved in the early T-lymphocyte specification and commitment as well as in oligodendrocytes dedifferentiation and development. The most significant transcription factors motifs were for the Early Growth response EGR/KROX family, ATF2, YY1 (Yin and Yang 1), E2F-1/DP-1 and E2F-4/DP-2 heterodimers, SOX5, and CREB and ATF families.
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Governments have recognised that the technological trades rely on knowledge embedded traditionally in science, technology, engineering and mathematics (STEM) disciplines. However, there is substantial evidence that students are turning away from these subjects in schools because the school curriculum is seen as irrelevant, with clear implications for not just vocational education but also higher education. In this paper, we report preliminary findings on the development of two curricula that attempt to integrate science and mathematics with workplace knowledge and practices. We argue that these curricula provide educational opportunities for students to pursue their preferred career pathways. These curricula were co-developed by industry and educational personnel across three industry sectors, namely, mining industry, aerospace and wine tourism. The aim was to provide knowledge appropriate for students moving from school to the workplace as trade apprentices in the respective industries. The analysis of curriculum and associated policy documents reveals that the curricula adopt applied learning orientations through teaching strategies and assessment practices which focus on practical skills. However, although key theoretical science and maths concepts have been well incorporated, the extent to which knowledge deriving from workplace practices is included varies across the curricula. The extent to which applications of concepts are included in the models depends on a number of factors not least the relevant expertise of the teacher as a practitioner in the industry. Our findings highlight the importance of teachers having substantial practical industry experience and the role that whole school policies play in attempts to align the range of learning experiences with the needs of industry.
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Several fringing coral reefs in Moreton Bay, Southeast Queensland, some 300 km south of the Great Barrier Reef (GBR), are set in a relatively high latitude, estuarine environment that is considered marginal for coral growth. Previous work indicated that these marginal reefs, as with many fringing reefs of the inner GBR, ceased accreting in the mid-Holocene. This research presents for the first time data from the subsurface profile of the mid-Holocene fossil reef at Wellington Point comprising U/Th dates of in situ and framework corals, and trace element analysis from the age constrained carbonate fragments. Based on trace element proxies the palaeo-water quality during reef accretion was reconstructed. Results demonstrate that the reef initiated more than 7,000 yr BP during the post glacial transgression, and the initiation progressed to the west as sea level rose. In situ micro-atolls indicate that sea level was at least 1 m above present mean sea level by 6,680 years ago. The reef remained in "catch-up" mode, with a seaward sloping upper surface, until it stopped aggrading abruptly at ca 6,000 yr BP; no lateral progradation occurred. Changes in sediment composition encountered in the cores suggest that after the laterite substrate was covered by the reef, most of the sediment was produced by the carbonate factory with minimal terrigenous influence. Rare earth element, Y and Ba proxies indicate that water quality during reef accretion was similar to oceanic waters, considered suitable for coral growth. A slight decline in water quality on the basis of increased Ba in the later stages of growth may be related to increased riverine input and partial closing up of the bay due to either tidal delta progradation, climatic change and/or slight sea level fall. The age data suggest that termination of reef growth coincided with a slight lowering of sea level, activation of ENSO and consequent increase in seasonality, lowering of temperatures and the constrictions to oceanic flushing. At the cessation of reef accretion the environmental conditions in the western Moreton Bay were changing from open marine to estuarine. The living coral community appears to be similar to the fossil community, but without the branching Acropora spp. that were more common in the fossil reef. In this marginal setting coral growth periods do not always correspond to periods of reef accretion due to insufficient coral abundance. Due to several environmental constraints modern coral growth is insufficient for reef growth. Based on these findings Moreton Bay may be unsuitable as a long term coral refuge for most species currently living in the GBR.
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Spectroscopic studies of complex clinical fluids have led to the application of a more holistic approach to their chemical analysis becoming more popular and widely employed. The efficient and effective interpretation of multidimensional spectroscopic data relies on many chemometric techniques and one such group of tools is represented by so-called correlation analysis methods. Typical of these techniques are two-dimensional correlation analysis and statistical total correlation spectroscopy (STOCSY). Whilst the former has largely been applied to optical spectroscopic analysis, STOCSY was developed and has been applied almost exclusively to NMR metabonomic studies. Using a 1H NMR study of human blood plasma, from subjects recovering from exhaustive exercise trials, the basic concepts and applications of these techniques are examined. Typical information from their application to NMR-based metabonomics is presented and their value in aiding interpretation of NMR data obtained from biological systems is illustrated. Major energy metabolites are identified in the NMR spectra and the dynamics of their appearance and removal from plasma during exercise recovery are illustrated and discussed. The complementary nature of two-dimensional correlation analysis and statistical total correlation spectroscopy are highlighted.
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Many primary teachers and preservice teachers experience a fear of science that translates into a fear of teaching science. Consequently, primary students may not receive a full science education curriculum, particularly as the teaching of science is avoided by many primary teachers, as shown in an Australian report by Goodrum, Hackling and Rennie ( 2001 ). Preservice teachers need to develop confi dence to teach primary science, by understanding what science is, knowing how to plan and assess science learning, and teaching science skills and knowledge in ways that engage students in science education.