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11.
The purpose of this study was to explore 15 graduate research assistants’ understanding of the nature of science. Data were collected through administration of a modified version of the Views of Nature of Science Questionnaire (VNOS-C). The findings suggest that graduate research assistants held underdeveloped views related to several nature of science (NOS) aspects including the argumentative nature of science, the process of modeling in science, scientists’ treatment of unexpected results, collaborative nature of science, and the process of theory formation. The discussion focuses on the missing link in preparation of future scientists and offers suggestions to address the learning needs of graduate research assistants regarding their understanding of NOS.  相似文献   
12.

Introduction

The collected and shipped blood samples are exposed to a various extra-analytical factors prior to analysis. The aim of the study was to determine the stability of analytes in serum gel tubes and plain tubes exposed to a range of storage temperatures and times after centrifugation.

Materials and methods:

Fifteen healthy volunteers were recruited and venous blood was collected into four tubes, two with and two without gel separator. Analyzing the baseline samples in 30 min, all were stored at 4ºC or 24ºC for 6, 12, 18, 24, 30, 36, 48 and 72 hours and 1 week. Sixteen biochemical anaytes were measured on each sample. Variations remained under the desirable bias considered as clinically insignificant.

Results:

On day three, most analytes remained stable including albumin, protein, creatinine, cholesterol, triglycerides, gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), alanine aminotransferase (ALT), creatine kinase (CK), lactate dehydrogenase (LD) regardless of tube types. Glucose concentration decreased markedly (P = 0.001) beginning from the first hours of storage in plain serum. The stability maximized for the analytes including glucose, total bilirubin, urea nitrogen (BUN), uric acid stored at 4 ºC in gel tubes. Aspartate aminotransferase (AST) activity increased significantly (P = 0.002) up to 48-h, however bias was not significant clinically. High density lipoprotein (HDL) concentration was stable in gel tubes at 24 ºC, in plain tubes at 4 ºC stored up to 36-h.

Conclusion:

Serum gel or non-gel tubes might be used interchangeably for 11 analytes chilled or at 24 ºC, whereas some restrictions must be applied for glucose, AST, BUN, HDL, and uric acid.  相似文献   
13.
Journal of Science Education and Technology - Today, science educators accept that digital literacy has been one of the key concepts for science teachers in terms of creating meaningful science...  相似文献   
14.
The present article scrutinizes “the unique American vision of childhood” (UAVC) as a phenomenon undermining high academic expectations and good work ethics, and in turn, contributing to the generally low academic achievement of U.S. students compared to their counterparts in other advanced countries. It starts with a definition of UAVC, followed by a discussion of how influential it has been. The article goes on to state three reasons why UAVC is troublesome and misleading, especially in an era of global competition. Excuses devised by the proponents for UAVC’s adverse effects are also revealed. The article ends with recommendations for future research and a conclusion elaborating on the consequences of UAVC and the likelihood that other countries might adopt a similar mentality.  相似文献   
15.
A Chebyshev collocation method, an expansion method, has been proposed in order to solve the systems of higher-order linear integro-differential equations. This method transforms the IDE system and the given conditions into the matrix equations via Chebyshev collocation points. By merging these results, a new system which corresponds to a system of linear algebraic equations is obtained. The solution of this system yields the Chebyshev coefficients of the solution function. Some numerical results are also given to illustrate the efficiency of the method. Moreover, this method is valid for the systems of differential and integral equations.  相似文献   
16.
Asia Pacific Education Review - The current study reports the findings of the first step of a comprehensive performance improvement study, identification of the optimal behaviors. In this sense,...  相似文献   
17.
The framework for this paper is a recently developed theory of abstraction in context. The paper reports on data collected from one student working on tasks concerned with absolute value functions. It examines the relationship between mathematical constructions and abstractions. It argues that an abstraction is a consolidated construction that can be used to create new constructions. Newly formed constructions are fragile entities. In the course of consolidating a construction this student creates connections between the new construction and already established mathematical knowledge and develops a language to describe and guide mathematical actions related to the construction. The resulting abstraction is a more resilient form of the construction and the student is able to justify his assertions. The paper also examines issues in designing tasks to consolidate a construction.  相似文献   
18.
The purpose of this study was to investigate the extent to which professional development predicts principals’ instructional leadership in order to identify whether a relationship exists between the duration of principals’ participation in distinct professional development activities and their perceived practice of instructional leadership while controlling for several principal and school characteristics. The data employed in this study came from the 2013 teaching and learning international survey, which was conducted by the organisation for economic co-operation and development. Four multivariate regression models with the country-controlled dummy variable were implemented in the analysis of the data. The results indicated that the more principals take part in contemporary professional development activities such as professional networking, mentoring and research activities, the more often they engage in instructional leadership practices. However, no relationship between more traditional types of professional development activities, such as courses, conferences, and observational visits, and principals’ instructional leadership, was found. The results have substantial implications for policy-makers and practitioners worldwide, suggesting that any professional development designed to get principles involved in more instructional leadership practices should be based on the contemporary type of professional development activities.  相似文献   
19.
ABSTRACT

Knowledge and human identity are socially constructed phenomena. Like other aspects of human identity, teacher identity is shaped through social influences. Some of the social influences that contribute to teacher identity development happen through critical incidents that teachers or teacher candidates experience. The current study, adopting a critical incident analysis perspective, attempts to ascertain the nature of the critical incidents that 49 pre-service teachers of EFL have experienced throughout their English learning process. It also tries to uncover the effects of these critical incidents on their English learning and teacher identity. The data for the research was collected using a Critical Incident Form developed by the researchers and focus group interviews. The findings indicated that pre-service ELT teachers’ early learning experiences included certain critical incidents. An inductive quantitative analysis of these incidents revealed that they can be categorized into three themes: people, context, and outcome. Exploring the nature of critical incidents and their role in the construction of English language teacher identity will hopefully be a benefit to teachers and teacher educators.  相似文献   
20.
The present study aimed at developing a scale to evaluate navigational performance as a whole, which is one of the factors influencing learning in hyper media. In line with this purpose, depending on the related literature, an item pool of 15 factors was prepared, and these variables were decreased to 5 based on the views of 38 field experts. In the end, a 3-factor structured was obtained via a pilot application carried out with 32 Information Technologies (IT) students, via the confirmatory factor analysis conducted with 110 IT students and via the reliability analysis carried out with 33 IT students. The scale included 14 items, and the internal consistency coefficient regarding the whole scale was calculated as α?=?0.90. The results of the Pearson correlation analysis revealed that the test-retest correlation coefficients of the items ranged between 0.762 and 0.954. As a result of the analyses conducted, the Hyper-MNP scale was found to be a valid and reliable tool that can be used to measure the navigational performance in hyper media.  相似文献   
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