935 resultados para Experimental science
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This chapter overviews the major themes of research reviewed and justifies the selection of topics.
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While teacher leadership is the basis for innovation and reform within schools, few international studies have focused on the leadership practices of science teachers and heads of science departments. This chapter reviews the Australasian literature that addresses the issue both directly and indirectly. The transformational practices of heads of science departments as well as influential science teachers within departments are identified in this chapter.
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The measurement of broadband ultrasonic attenuation (BUA) in cancellous bone at the calcaneus was first described in 1984. The assessment of osteoporosis by BUA has recently been recognized by Universities UK, within its EurekaUK book, as being one of the “100 discoveries and developments in UK Universities that have changed the world” over the past 50 years, covering the whole academic spectrum from the arts and humanities to science and technology. Indeed, BUA technique has been clinically validated and is utilized worldwide, with at least seven commercial systems providing calcaneal BUA measurement. However, a fundamental understanding of the dependence of BUA upon the material and structural properties of cancellous bone is still lacking. This review aims to provide a science- and technology-orientated perspective on the application of BUA to the medical disease of osteoporosis.
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In recent decades, concepts and ideas from James J. Gibson’s theory of direct perception in ecological psychology have been applied to the study of how perception and action regulate sport performance. This article examines the influence of different streams of thought in ecological psychology for studying cognition and action in the diverse behavioural contexts of sport and exercise. In discussing the origins of ecological psychology it can be concluded that psychologists such as Lewin, and to some extent Heider, provided the initial impetus for the development of key ideas. We argue that the papers in this special issue clarify that the different schools of thinking in ecological psychology have much to contribute to theoretical and practical developments in sport and exercise psychology. For example, Gibson emphasized and formalized how the individual is coupled with the environment; Brunswik raised the issue of the ontology of probability in human behaviour and the problem of representative design for experimental task constraints; Barker looked carefully into extra-individual behavioural contexts and Bronfenbrenner presented insights pertinent to the relations between behaviour contexts, and macro influences on behaviour. In this overview, we highlight essential issues from the main schools of thought of relevance to the contexts of sport and exercise, and we consider some potential theoretical linkages with dynamical systems theory.
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Cancer represents a major public health concern in Australia. Causes of cancer are multifactorial with lack of physical activity being considered one of the known risk factors, particularly for breast and colorectal cancers. Participating in exercise has also been associated with benefits during and following treatment for cancer, including improvements in psychosocial and physical outcomes, as well as better compliance with treatment regimens, reduced impact of disease symptoms and treatment-related side effects, and survival benefits for particular cancers. The general exercise prescription for people undertaking or having completed cancer treatment is of low to moderate intensity, regular frequency (3-5 times/week) for at least 20 minutes per session, involving aerobic, resistance or mixed exercise types. Future work needs to push the boundaries of this exercise prescription, so that we can better understand what constitutes optimal, desirable and necessary frequency, duration, intensity and type, and how specific characteristics of the individual (e.g., age, cancer type, treatment, presence of specific symptoms) influence this prescription. What follows is a summary of the cancer and exercise literature, in particular the purpose of exercise following diagnosis of cancer, the potential benefits derived by cancer patients and survivors from participating in exercise programs, and exercise prescription guidelines and contraindications or considerations for exercise prescription with this special population. This report represents the position stand of the Australian Association of Exercise and Sport Science on exercise and cancer recovery and has the purpose of guiding Accredited Exercise Physiologists in their work with cancer patients.
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The Perth Declaration on Science and Technology Education of 2007 expresses strong concern about the state of science and technology education worldwide and calls on governments to respond to a number of suggestions for establishing the structural conditions for their improved practice. The quality of school education in science and technology has never before been of such critical importance to governments. There are three imperatives for its critical importance. The first relates to the traditional role of science in schooling, namely the identification, motivation and initial preparation of those students who will go on to further studies for careers in all those professional fi elds that directly involve science and technology. A suffi cient supply of these professionals is vital to the economy of all countries and to the health of their citizens. In the 21st century they are recognised everywhere as key players in ensuring that industrial and economic development occurs in a socially and environmentally sustainable way. In many countries this supply is now falling seriously short and urgently needs to be addressed. The second imperative is that sustainable technological development and many other possible societal applications of science require the support of scientifically and technologically informed citizens. Without the support and understanding of citizens, technological development can all too easily serve short term and sectional interests. The longer term progress of the whole society is overlooked, citizens will be confused about what should, and what should not be supported, and reactive and the environment will continue to be destroyed rather than sustained. Sustainable development, and the potential that science and technology increasingly offers, involves societies in ways that can often interact strongly, with traditional values, and hence, making decisions about them involve major moral decisions. All students need to be prepared through their science and technology education to be able to participate actively as persons and as responsible citizens in these essential and exciting possibilities. This goal is far from being generally achieved at present, but pathways to it are now more clearly understood. The third imperative derives from the changes that are resulting from the application of digital technologies that are the most rapid, the most widespread, and probably the most pervasive influence that science has ever had on human society. We all, wherever we live, are part of a global communication society. Information exchange and access to it that have been hitherto the realm of the few, are now literally in the hands of individuals. This is leading to profound changes in the World of Work and in what is known as the Knowledge Society. Schooling is now being challenged to contribute to the development in students of an active repertoire of generic and subject-based competencies. This contrasts very strongly with existing priorities, in subjects like the sciences that have seen the size of a student’s a store of established knowledge as the key measure of success. Science and technology education needs to be a key component in developing these competencies. When you add to these imperatives, the possibility that a more effective education in science and technology will enable more and more citizens to delight in, and feel a share in the great human enterprise we call Science, the case for new policy decisions is compellingly urgent. What follows are the recommendations (and some supplementary notes) for policy makers to consider about more operational aspects for improving science and technology education. They are listed under headings that point to the issues within each of these aspects. In the full document, a background is provided to each set of issues, including the commonly current state of science and technology education. Associated with each recommendation for consideration are the positive Prospects that could follow from such decision making, and the necessary Prerequisites, if such bold policy decisions are to fl ow, as intended, into practice in science and technology classrooms.
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Research in science education is now an international activity. This book asks for the first time, Does this research activity have an identity?-It uses the significant studies of more than 75 researchers in 15 countries to see to what extent they provide evidence for an identity as a distinctive field of research.-It considers trends in the research over time, and looks particularly at what progression in the research entails.-It provides insight into how researchers influence each other and how involvement in research affects the being of the researcher as a person.-It addresses the relation between research and practice in a manner that sees teaching and learning in the science classroom as interdependent with national policies and curriculum traditions about science. It gives graduate students and other early researchers an unusual overview of their research area as a whole. Established researchers will be interested in, and challenged by, the identity the author ascribes to the research and by the plea he makes for the science content itself to be seen as problematic.
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This paper presents a novel algorithm for the gateway placement problem in Backbone Wireless Mesh Networks (BWMNs). Different from existing algorithms, the new algorithm incrementally identifies gateways and assigns mesh routers to identified gateways. The new algorithm can guarantee to find a feasible gateway placement satisfying Quality-of-Service (QoS) constraints, including delay constraint, relay load constraint and gateway capacity constraint. Experimental results show that its performance is as good as that of the best of existing algorithms for the gateway placement problem. But, the new algorithm can be used for BWMNs that do not form one connected component, and it is easy to implement and use.
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Following an early claim by Nelson & McEvoy suggesting that word associations can display `spooky action at a distance behaviour', a serious investigation of the potentially quantum nature of such associations is currently underway. In this paper quantum theory is proposed as a framework suitable for modelling the mental lexicon, specifically the results obtained from both intralist and extralist word association experiments. Some initial models exploring this hypothesis are discussed, and they appear to be capable of substantial agreement with pre-existing experimental data. The paper concludes with a discussion of some experiments that will be performed in order to test these models.
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Total cross sections for neutron scattering from nuclei, with energies ranging from 10 to 600 MeV and from many nuclei spanning the mass range 6Li to 238U, have been analyzed using a simple, three-parameter, functional form. The calculated cross sections are compared with results obtained by using microscopic (g-folding) optical potentials as well as with experimental data. The functional form reproduces those total cross sections very well. When allowance is made for Ramsauer-like effects in the scattering, the parameters of the functional form required vary smoothly with energy and target mass. They too can be represented by functions of energy and mass.
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For a number of years now it has been evident that the major issue facing science educators in the more developed countries of the world is the quantitative decline in enrolments in the senior secondary sciences, particularly the physical sciences, and in the number of higher achieving students applying for places in universities to undertake further studies in science. The deep malaise in school science to which these quantitative measures point has been elucidated by more qualitative studies of the students’ experience of studying science in secondary school in several of these countries (Sweden, Lindahl (2003); England, Simon and Osborne (2002); and Australia, Lyons (2005)). Remarkably concordant descriptions of these experiences can be summarized as: School science is: • transmission of knowledge from the teacher or the textbook to the students. • about content that is irrelevant and boring to our lives. • difficult to learn in comparison with other subjects Incidentally, the Australian study only involved consistently high achieving students; but even so, most of them found science more difficult than other more interesting subjects, and concluded that further science studies should be avoided unless they were needed for some career purpose. Other more representative confirmations of negative evaluations of the science curricula across Australia (and in particular states) are now available in Australia, from the large scale reviews of Goodrum, Hackling and Rennie (2001) and from the TIMSS (2002). The former reported that well under half of secondary students find the science at school relevant to my future, useful ion everyday life, deals with things I am concerned with and helps me make decisions about my health.. TIMSS found that 62 and 65 % of females and males in Year 4 agree with I like learning science, but by Year 8 only 26 and 33 % still agree. Students in Japan have been doubly notably because of (a) their high performance in international measures of science achievement like TIMSS and PISA and (b) their very low response to items in these studies which relate to interest in science. Ogura (2003) reported an intra-national study of students across Years 6-9 (upper primary through Junior High); interest in a range of their subjects (including science) that make up that country’s national curriculum. There was a steady decline in interest in all these subjects which might have indicated an adolescent reaction against schooling generally. However, this study went on to ask the students a further question that is very meaningful in the Japanese context, If you discount the importance of this subject for university entrance, is it worth studying? Science and mathematics remained in decline while all the other subjects were seen more positively. It is thus ironic, at a time when some innovations in curriculum and other research-based findings are suggesting ways that these failures of school science might be corrected, to find school science under a new demands that come from quite outside science education, and which certainly do not have the correction of this malaise as a priority. The positive curricular and research findings can be characterized as moves from within science education, whereas the new demands are moves that come from without science education. In this paper I set out these two rather contrary challenges to the teaching of science as it is currently practised, and go on to suggest a way forward that could fruitfully combine the two.
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This special issue aims to provide up-to-date knowledge and the latest scientific concepts and technological developments in the processing, characterization, testing, mechanics, modeling and applications of a broad range of advanced materials. The many contributors, from Denmark, Germany, UK, Iran, Saudi Arabia, Malaysia, Japan, the People’s Republic of China, Singapore, Taiwan, USA, New Zealand and Australia, present a wide range of topics including: nanomaterials, thin films and coatings, metals and alloys, composite materials, materials processing and characterization, biomaterials and biomechanics, and computational materials science and simulation. The work will therefore be of great interest to a broad spectrum of researchers and technologists.
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Understanding users' capabilities, needs and expectations is key to the domain of Inclusive Design. Much of the work in the field could be informed and further strengthened by clear, valid and representative data covering the full range of people's capabilities. This article reviews existing data sets and identifies the challenges inherent in measuring capability in a manner that is informative for work in Inclusive Design. The need for a design-relevant capability data set is identified and consideration is given to a variety of capability construct operationalisation issues including questions associated with self-report and performance measures, sampling and the appropriate granularity of measures. The need for further experimental work is identified and a programme of research designed to culminate in the design of a valid and reliable capability survey is described.
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In the filed of semantic grid, QoS-based Web service scheduling for workflow optimization is an important problem.However, in semantic and service rich environment like semantic grid, the emergence of context constraints on Web services is very common making the scheduling consider not only quality properties of Web services, but also inter service dependencies which are formed due to the context constraints imposed on Web services. In this paper, we present a repair genetic algorithm, namely minimal-conflict hill-climbing repair genetic algorithm, to address scheduling optimization problems in workflow applications in the presence of domain constraints and inter service dependencies. Experimental results demonstrate the scalability and effectiveness of the genetic algorithm.
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In Web service based systems, new value-added Web services can be constructed by integrating existing Web services. A Web service may have many implementations, which are functionally identical, but have different Quality of Service (QoS) attributes, such as response time, price, reputation, reliability, availability and so on. Thus, a significant research problem in Web service composition is how to select an implementation for each of the component Web services so that the overall QoS of the composite Web service is optimal. This is so called QoS-aware Web service composition problem. In some composite Web services there are some dependencies and conflicts between the Web service implementations. However, existing approaches cannot handle the constraints. This paper tackles the QoS-aware Web service composition problem with inter service dependencies and conflicts using a penalty-based genetic algorithm (GA). Experimental results demonstrate the effectiveness and the scalability of the penalty-based GA.