848 resultados para Kalai, Ehud. Rational learning lead to Nash equilibrium
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Purpose To investigate the prevalence of infected herniated nucleus material in lumbar disc herniations and to determine if patients with an anaerobic infected disc are more likely to develop Modic change (MC) (bone oedema) in the adjacent vertebrae after the disc herniation. MCs (bone oedema) in vertebrae are observed in 6 % of the general population and in 35-40 % of people with low back pain. These changes are strongly associated with low back pain. There are probably a mechanical cause and an infective cause that causes MC. Several studies on nuclear tissue from herniated discs have demonstrated the presence of low virulent anaerobic microorganisms, predominantly Propionibacterium acnes, in 7-53 % of patients. At the time of a herniation these low virulent anaerobic bacteria may enter the disc and give rise to an insidious infection. Local inflammation in the adjacent bone may be a secondary effect due to cytokine and propionic acid production. Methods Patients undergoing primary surgery at a single spinal level for lumbar disc herniation with an MRI-confirmed lumbar disc herniation, where the annular fibres were penetrated by visible nuclear tissue, had the nucleus material removed. Stringent antiseptic sterile protocols were followed. Results Sixty-one patients were included, mean age 46.4 years (SD 9.7), 27 % female. All patients were immunocompetent. No patient had received a previous epidural steroid injection or undergone previous back surgery. In total, microbiological cultures were positive in 28 (46 %) patients. Anaerobic cultures were positive in 26 (43 %) patients, and of these 4 (7 %) had dual microbial infections, containing both one aerobic and one anaerobic culture. No tissue specimens had more than two types of bacteria identified. Two (3 %) cultures only had aerobic bacteria isolated. In the discs with a nucleus with anaerobic bacteria, 80 % developed new MC in the vertebrae adjacent to the previous disc herniation. In contrast, none of those with aerobic bacteria and only 44 % of patients with negative cultures developed new MC. The association between an anaerobic culture and new MCs is highly statistically significant (P = 0.0038), with an odds ratio of 5.60 (95 % CI 1.51-21.95). Conclusion These findings support the theory that the occurrence of MCs Type 1 in the vertebrae adjacent to a previously herniated disc may be due to oedema surrounding an infected disc. The discs infected with anaerobic bacteria were more likely (P<0.0038) to develop MCs in the adjacent vertebrae than those in which no bacteria were found or those in which aerobic bacteria were found. © Springer-Verlag Berlin Heidelberg 2013.
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Administration of active TG2 to two different in vitro angiogenesis assays resulted in the accumulation of a complex extracellular matrix (ECM) leading to the suppression of endothelial tube formation without causing cell death. Matrix accumulation was accompanied by a decreased rate of ECM turnover, with increased resistance to matrix metalloproteinase-1. Intratumor injection of TG2 into mice bearing CT26 colon carcinoma tumors demonstrated a reduction in tumor growth, and in some cases tumor regression. In TG2 knockout mice, tumor progression was increased and survival rate reduced compared to wild-type mice. In wild-type mice, an increased presence of TG2 was detectable in the host tissue around the tumor. Analysis of CT26 tumors injected with TG2 revealed fibrotic-like tissue containing increased collagen, TG2-mediated crosslink and reduced organized vasculature. TG2-mediated modulation of cell behavior via changes in the ECM may provide a new approach to solid tumor therapy.
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There has been a strong move recently to make degrees more applicable to employment; including work placements as part of the programme is one way of achieving this. Such placements are advocated to increase employability, but also for improving academic performance. This paper examines the relationship between undertaking a work placement and the class of degree achieved. It challenges earlier findings that undertaking a placement increases degree results. Studying seven cohorts of students, a well tested approach was employed that allows for sample selection – i.e. whether better students do placements rather than whether placements produce better students. The paper concludes that the sample selection is much stronger, i.e. placement students do better because they are better students. The results highlight that it is not merely doing a placement that matters, but a successful placement adds significantly to subsequent performance. The paper concludes with advice to students and policy makers.
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We study waveguide fabrication in lithium-niobo-phosphate glass, aiming at a practical method of single-stage fabrication of nonlinear integrated-optics devices. We observed chemical transformations or material redistribution during the course of high repetition rate femtosecond laser inscription. We believe that the laser-induced ultrafast heating and cooling followed by elements diffusion on a microscopic scale opens the way toward the engineering non-equilibrium sates of matter and thus can further enhance Refractive Index (RI) contrasts by virtue of changing glass composition in and around the fs tracks. © 2014 Optical Society of America.
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The National Institute for Transport and Logistics (NITL) is Ireland’s centre of excellence for supply chain management (SCM). As part of its mission to promote the development of supply chain expertise in Irish business, it designs and delivers executive modular learning programmes. In 2004, as part of a drive to create more flexible learning opportunities for course participants, NITL designed and implemented an eLearning programme, which involved converting traditionally tutored modules to online modules. This paper describes the rationale behind this initiative and the significance of technology as an enabling tool for executive education, as well as detailing the design and implementation processes for the pilot module. The paper concludes with a critique of the expected and actual benefits realised, as well as future development considerations.
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Assessment criteria are increasingly incorporated into teaching, making it important to clarify the pedagogic status of the qualities to which they refer. We reviewed theory and evidence about the extent to which four core criteria for student writing-critical thinking, use of language, structuring, and argument-refer to the outcomes of three types of learning: generic skills learning, a deep approach to learning, and complex learning. The analysis showed that all four of the core criteria describe to some extent properties of text resulting from using skills, but none qualify fully as descriptions of the outcomes of applying generic skills. Most also describe certain aspects of the outcomes of taking a deep approach to learning. Critical thinking and argument correspond most closely to the outcomes of complex learning. At lower levels of performance, use of language and structuring describe the outcomes of applying transferable skills. At higher levels of performance, they describe the outcomes of taking a deep approach to learning. We propose that the type of learning required to meet the core criteria is most usefully and accurately conceptualized as the learning of complex skills, and that this provides a conceptual framework for maximizing the benefits of using assessment criteria as part of teaching. © 2006 Taylor & Francis.
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This article reports on an investigationwith first year undergraduate ProductDesign and Management students within a School of Engineering and Applied Science. The students at the time of this investigation had studied fundamental engineering science and mathematics for one semester. The students were given an open ended, ill-formed problem which involved designing a simple bridge to cross a river.They were given a talk on problemsolving and given a rubric to follow, if they chose to do so.They were not given any formulae or procedures needed in order to resolve the problem. In theory, they possessed the knowledge to ask the right questions in order tomake assumptions but, in practice, it turned out they were unable to link their a priori knowledge to resolve this problem. They were able to solve simple beam problems when given closed questions. The results show they were unable to visualize a simple bridge as an augmented beam problem and ask pertinent questions and hence formulate appropriate assumptions in order to offer resolutions.
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Bayesian algorithms pose a limit to the performance learning algorithms can achieve. Natural selection should guide the evolution of information processing systems towards those limits. What can we learn from this evolution and what properties do the intermediate stages have? While this question is too general to permit any answer, progress can be made by restricting the class of information processing systems under study. We present analytical and numerical results for the evolution of on-line algorithms for learning from examples for neural network classifiers, which might include or not a hidden layer. The analytical results are obtained by solving a variational problem to determine the learning algorithm that leads to maximum generalization ability. Simulations using evolutionary programming, for programs that implement learning algorithms, confirm and expand the results. The principal result is not just that the evolution is towards a Bayesian limit. Indeed it is essentially reached. In addition we find that evolution is driven by the discovery of useful structures or combinations of variables and operators. In different runs the temporal order of the discovery of such combinations is unique. The main result is that combinations that signal the surprise brought by an example arise always before combinations that serve to gauge the performance of the learning algorithm. This latter structures can be used to implement annealing schedules. The temporal ordering can be understood analytically as well by doing the functional optimization in restricted functional spaces. We also show that there is data suggesting that the appearance of these traits also follows the same temporal ordering in biological systems. © 2006 American Institute of Physics.
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This paper discusses the integration of quiz mechanism into digital game-based learning platform addressing environmental and social issues caused by population growth. 50 participants' learning outcomes were compared before and after the session. Semi-structured interview was used to gather participants' viewpoints regarding of issues presented in the game. Phenomenography was used as a methodology for data collection and analysis. Preliminary outcomes have shown that the current game implementation and quiz mechanism can be used to: (1) promote learning and awareness on environmental and social issues and (2) sustain players' attention and engagements.
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The paper explores the functionalities of eight start pages and considers their usefulness when used as a mashable platform for deployment of personal learning environments (PLE) for self-organized learners. The Web 2.0 effects and eLearning 2.0 strategies are examined from the point of view of how they influence the methods of gathering and capturing data, information and knowledge, and the learning process. Mashup technology is studied in order to see what kind of components can be used in PLE realization. A model of a PLE for self-organized learners is developed and it is used to prototype a personal learning and research environment in the start pages Netvibes, Pageflakes and iGoogle.
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This paper consolidates evidence and material from a range of specialist and disciplinary fields to provide an evidence-based review and synthesis on the design and use of serious games in higher education. Search terms identified 165 papers reporting conceptual and empirical evidence on how learning attributes and game mechanics may be planned, designed and implemented by university teachers interested in using games, which are integrated into lesson plans and orchestrated as part of a learning sequence at any scale. The findings outline the potential of classifying the links between learning attributes and game mechanics as a means to scaffold teachers’ understanding of how to perpetuate learning in optimal ways while enhancing the in-game learning experience. The findings of this paper provide a foundation for describing methods, frames and discourse around experiences of design and use of serious games, linked to methodological limitations and recommendations for further research in this area.
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The purpose of this study was to investigate the relationship between organizational learning and expatriation in overseas subsidiaries as well as in organizations as a whole. In doing so, two issues were addressed--(i) the use of expatriation as firms internationalize, and (ii) the significance of various factors to expatriate success as firms gain international experience. The sample of companies for this study was drawn from U.S. Fortune 500 multinational corporations (MNCs) in two sets of related industries--computers/electronics and petroleum/chemicals. Based on the learning that takes place within organizations as they increase their involvement overseas, a positive relationship was expected between international experience and expatriation when internationalization was low, and a negative relationship was expected when internationalization was high. Results indicate a significant positive relationship between country experience and the proportion of expatriates in that subsidiary when subsidiaries were relatively young, and a negative relationship, however not significant, for more mature subsidiaries. The relationship between overall firm degree of internationalization (DOI) and the proportion of expatriates in the firm as a whole was negative regardless of stage of internationalization, but this relationship was significant only for highly internationalized firms. It was further suspected that individual, environmental, and family-related characteristics would have a significant effect on the success of expatriates whose firms were low on internationalization, and that organizational characteristics would play a significant role in highly internationalized firms. Support for these hypotheses was received with respect to certain outcomes and some determinants of success. The preponderance of support was found for those addressing the effects of both environmental and family-related characteristics on the cross-cultural adjustment of expatriates in firms with little international experience. Considerable support was also found for those hypotheses addressing the impact of organizational characteristics on the job satisfaction levels of expatriates assigned to mature subsidiaries. The relevant literatures on organizational learning and expatriation are reviewed, and a model is developed underlying the logic of the hypotheses. Research methods are then described in full detail, results are reported, and implications for theory and for management are discussed. ^