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This study investigated the distribution of incentives (e.g., certificates, badges) for massive open online course (MOOC) completion, and relationships between incentives and MOOC outcomes. Participants were 779 MOOC students internationally who participated in at least 303 different MOOCs offered by at least 12 providers. MOOC participants most commonly intended to receive, and in actuality received, free and paid course certificates of completion; other incentives (e.g., digital badges, postsecondary credits) were far less common. In addition, MOOC participants' intentions to receive both free and paid certificates were consistently and positively related to perceived learning and course completion, net other factors. (Keywords: massive open online courses, MOOCs, motivation, incentives, microcredentials, certificates of completion)  相似文献   
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Introduction

Total 25-hydroxyvitamin D [25(OH)D] is the most reliable indicator of vitamin D status. In this study, we compared two automated immunoassay methods, the Abbott Architect 25-OH Vitamin D assay and the Roche Cobas Vitamin D total assay, with the liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Materials and methods

One hundred venous blood samples were randomly selected from routine vitamin D tests. Two of the serum aliquots were analyzed at the Abbott Architect i2000 and the Roche Cobas 6000’s module e601 in our laboratory within the same day. The other serum aliquots were analyzed at the LC-MS/MS in different laboratory. Passing-Bablok regression analysis and Bland-Altman plot were used to compare methods. Inter-rater agreement was analyzed using kappa (κ) analysis.

Results

The Roche assay showed acceptable agreement with the LC-MS/MS based on Passing-Bablok analysis (intercept: -5.23 nmol/L, 95% CI: -8.73 to 0.19; slope: 0.97, 95% CI: 0.77 to 1.15). The Abbott assay showed proportional (slope: 0.77, 95% CI: 0.67 to 0.85) and constant differences (intercept: 17.08 nmol/L; 95% CI: 12.98 to 21.39). A mean bias of 15.1% was observed for the Abbott and a mean bias of -14.1% was observed for the Roche based on the Bland-Altman plots. We found strong to nearly perfect agreement in vitamin D status between the immunoassays and LC-MS/MS. (κ: 0.83 for Abbott, κ: 0.93 for Roche) using kappa analysis.

Conclusion

Both immunoassays demonstrated acceptable performance, but the Roche Cobas assay demonstrated better performance than the Abbott Architect in the studied samples.Key words: 25-Hydroxyvitamin D, chromatography, immunoassay, methods, tandem mass spectrometry  相似文献   
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The set of papers [3], [4], [6] and [7] (Chattopadhyay et al., 1999; Dihidar and Choudhury, 2004; Khan et al., 1997, 1999) deals with the behavior of the uniform two-dimensional cellular automata over binary fields (Z2). Some structural properties and precise mathematical models using matrix algebra over the field Z2 are reported for characterizing the behavior of two-dimensional nearest neighborhood linear cellular automata with null and periodic boundary conditions [3], [4], [6] and [7] (Chattopadhyay et al., 1999; Dihidar and Choudhury, 2004; Khan et al., 1997, 1999). In this paper, we characterize two-dimensional linear cellular automata transformations by using matrix algebra built on Z3. We analyze some results for two-dimensional CA with rule numbers 2460N and 2460P. Finally, we investigate the dimension of the kernel of two-dimensional cellular automata defined by the rule number 2460N.  相似文献   
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Blockchain plays a vital task in cybersecurity. With the exerted efforts for realising large-scale quantum computers, most current cryptographic mechanisms may be hacked. Accordingly, we need a quantum tool utilised for designing blockchain frameworks to have the ability to be executed in the level of digital computers and resist the probable attacks from both digital and quantum computers. Quantum walks may be utilised as a quantum-inspired model for designing new cryptographic algorithms. In this paper, we present a new authentication and encryption protocol based on quantum-inspired quantum walks (QIQW). The proposed protocol is utilized to build a blockchain framework for secure data transmission among IoT devices. Instead of using classical cryptographic hash functions, quantum hash functions based on QIQW are employed for linking blocks of the chain. The main advantages of the presented framework are helping IoT nodes to effectively share their data with other nodes and full control of their records. Security analysis demonstrates that our proposed protocol can defend against message attack and impersonation attacks, thus ensuring secure transmission of data among IoT devices.  相似文献   
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A bstract .  Bell-curve thinking, as a model of distribution of success and failure in society, enjoys a perennial (ahistorical, objective, and law-like) status in education. As such it provides a rationale for sorting (tracking or streaming) practices in education, which has led many educators to criticize both bell-curve thinking and associated sorting practices. In this essay, Lynn Fendler and Irfan Muzaffar argue that the existing critiques of bell-curve thinking ring true for people who believe that the purpose of schooling is to promote a more equitable redistribution of resources in society; however, these arguments do not criticize the law-like character assumed for a bell curve as a representation of social reality. To extend these critiques, Fendler and Muzaffar focus on the history of the bell curve, from a representation of binomial probability, to a bearer of real things in nature, and finally to a set of expectations about how people should behave. They ultimately argue that the acceptance of bell-curve thinking in education is part of a recursive project of governance and normalization.  相似文献   
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In this study, using multiple regression analysis, we aimed to explore the factors related to acceptance of evolutionary theory among preservice Turkish biology teachers using conceptual ecology for biological evolution as a theoretical lens. We aimed to determine the extent to which we can account for the variance in acceptance of evolutionary theory by using understanding of evolutionary theory, epistemological beliefs, thinking dispositions, and parents' educational level as independent variables. Preservice biology teachers' thinking dispositions, their understanding of evolutionary theory, and their parents' educational level are positively correlated with acceptance of evolutionary theory. We did not find any significant positive correlation between epistemological beliefs and acceptance of evolution because of low reliability coefficients of subscales of the epistemological beliefs instrument. Together they explained 10.5% of the variance. These results suggest that studying the relationship between acceptance of evolutionary theory and other related factors in a multivariate context is more informative than examining the relationship between acceptance of evolutionary theory and other factors in isolation. Our findings indicate that studying a controversial issue such as acceptance of evolutionary theory in a multivariate fashion, using conceptual ecology as a theoretical lens to interpret the findings, is informative. Our results suggest the inclusion of thinking dispositions in conceptual ecology for biological evolution. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 45: 420–443, 2008  相似文献   
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The e-Government phenomenon has become more important with the ever increasing number of implementations worldwide. A model explaining the e-Government adoption and the related measurement instrument – a survey – had been developed and validated in this study. In a post Technology Acceptance Model (TAM) approach, theory of planned behavior (TPB) was extended to fit the requirements of e-Government context. The adoption of student loans service of the higher education student loans and accommodation association of Turkey (KYK) was investigated to obtain data for empirical validation. The instrument was administered to over four-hundred students and partial least squares path modeling was employed to analyze the data. The results indicate that the model was an improvement over TAM in terms of predictive power. The constructs trust, perceived behavioral control and attitudes successfully explained the intention to use an e-Government service. The findings presented in this study provide useful insights for researchers and policy makers when dealing with e-Government services.  相似文献   
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