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851.
    
This research investigated students' understanding of electrochemistry following a 7–9-week course of instruction. A list of conceptual and propositional knowledge statements was formulated, and this provided the framework for semistructured interviews that were conducted with 32 students in their final year of high school chemistry, following instruction in electrochemistry. Three misconceptions identified in this study and five which have been reported earlier are incorporated into an alternative framework about electric current. The framework is grounded on the notion that a current always involves drifting electrons, even in solution. Another area where students' misconceptions were prevalent was in relation to the sign of the anode and cathode. Students who thought the anode was negatively charged believed cations would move toward it, and those who thought it was positively charged were unable to explain why electrons move away from it. Electrolytic cells also proved troublesome for students. Many students did not associate the positions of the anode and cathode with the polarity of the applied electromotive force (e.m.f.). Other students attempted to reverse features of electrochemical cells and apply the reversals to electrolytic cells. The implications of the research relate to students' interpretation of the language that is used to describe scientific phenomena and the tendency for students to overgeneralize, due to comments made by teachers or statements in textbooks.  相似文献   
852.
    
The researchers conducting this study investigated the relationship between early childhood teachers' educational levels and their beliefs about appropriate and inappropriate practices by examining the differences between lead teachers and teacher assistants in publicly funded prekindergarten classrooms. For this purpose, the researchers analyzed self-reported teachers' beliefs using analysis of variance and examined 26 individual items. Findings of this study suggest that lead teachers endorsed developmentally appropriate practices more strongly than did teacher assistants. Teacher assistants were more likely than lead teachers to agree with developmentally inappropriate practices. Despite the significant differences between the two groups of teachers, it is important to note that there was a general tendency for both lead teachers and teacher assistants to endorse developmentally appropriate practices. Thus, although there appears to be a link between teachers' educational levels and teacher beliefs, teachers' educational levels alone may not be sufficient for understanding their beliefs and practices in the classroom. Implications for practice and future research in teacher education are also discussed.  相似文献   
853.
854.
    
ABSTRACT

Using classical and quantile regression analyses, we investigated whether predictor variables for early reading comprehension differed depending on language background and ability level in a mixed group of 161 monolingual (L1) and bilingual (L2) children in second grade (6–8 years). Although L2 readers scored lower on oral language skills and reading comprehension, the prediction of reading comprehension was similar for L1 and L2 readers. Classical regression identified decoding, vocabulary, and morphosyntactic knowledge as unique predictors with no interaction with language background. Quantile regression demonstrated that the prediction of reading comprehension differed across ability levels; decoding and morphosyntactic knowledge were consistently unique predictors, but vocabulary was uniquely related only for poor comprehenders and working memory only for good comprehenders. In both types of analysis, language background did not explain unique variance, indicating that individual differences in the predictor variables explained the L1–L2 performance gap in early reading comprehension across the ability range.  相似文献   
855.
Our study explored the contribution of gender role stress (GRS) and sociocultural appearance demands to symptoms of muscle dysmorphia (MD) in a college sample of 219 women and 154 men. For women, five GRS subscales, sociocultural appearance demands, age, and frequency of aerobic exercise predicted MD symptoms (model R2 = .33; F(8,210) = 12.81, p < . 001); for men, only one GRS subscale, age, and sociocultural appearance demands predicted MD symptoms (model R2 = .40; F(3,150) = 9.52, p < .001). Post hoc analyses revealed that a small number of items explained a substantial portion of the variation, suggesting that MD may be more related to specific perceptions of pressure to attain an attractive body than to global gender role stress.  相似文献   
856.
The identification and use of molecular biomarkers have greatly improved the diagnosis and treatment of malignant tumors. However, a much deeper understanding of oncogenic proteins is needed for the benefit to cancer patients. The lipid raft marker proteins, flotillin-1 and flotillin-2, were first found in goldfish retinal ganglion cells during axon regeneration. They have since been found in a variety of cells, mainly on the inner surface of cell membranes, and not only act as a skeleton to provide a platform for protein–protein interactions, but also are involved in signal transduction, nerve regeneration, endocytosis, and lymphocyte activation. Previous studies have shown that flotillins are closely associated with tumor development, invasion, and metastasis. In this article, we review the functions of flotillins in relevant cell processes, their underlying mechanisms of action in a variety of tumors, and their potential applications to tumor molecular diagnosis and targeted therapy.  相似文献   
857.
The present study sought to investigate the effects of a multidimensional educational intervention on high school students’ motivation and engagement. The intervention incorporated: (a) multidimensional targets of motivation and engagement, (b) empirically derived intervention methodology, (c) research-based risk and protective factors, (d) established practices that nurture optimal youth development, (e) use of interpersonally skilled staff, and (f) evidence-based programming. Using a pre-/post-treatment/control group design, it was found that the self-complete intervention brought about significant shifts in motivation and engagement. Specifically, findings showed that the treatment group made positive motivation shifts on key dimensions including task management, persistence, anxiety, failure avoidance, and uncertain control. Moreover, against a large weighted external comparison group, the treatment group made positive shifts on valuing, mastery orientation, planning, task management, persistence, failure avoidance, uncertain control, and self-handicapping. Taken together, these findings attest to the potential for multidimensional educational interventions for enhancing students’ motivation and engagement.  相似文献   
858.
Luck (2009) argues that gamers face a dilemma when it comes to performing certain virtual acts. Most gamers regularly commit acts of virtual murder, and take these acts to be morally permissible. They are permissible because unlike real murder, no one is harmed in performing them; their only victims are computer-controlled characters, and such characters are not moral patients. What Luck points out is that this justification equally applies to virtual pedophelia, but gamers intuitively think that such acts are not morally permissible. The result is a dilemma: either gamers must reject the intuition that virtual pedophelic acts are impermissible and so accept partaking in such acts, or they must reject the intuition that virtual murder acts are permissible, and so abstain from many (if not most) extant games. While the prevailing solution to this dilemma has been to try and find a morally relevant feature to distinguish the two cases, I argue that a different route should be pursued. It is neither the case that all acts of virtual murder are morally permissible, nor are all acts of virtual pedophelia impermissible. Our intuitions falter and produce this dilemma because they are not sensitive to the different contexts in which games present virtual acts.  相似文献   
859.
Community sport organizations (CSOs) provide valuable contexts for promoting community development. These initiatives are most effective when they involve local stakeholders in the process of development. A key first step to achieving this objective is building community capacity, defined as local stakeholders’ skills, knowledge, and resources that may be leveraged for change. Interestingly, despite this conceptual importance, few researchers have focused on capacity building in the sport context. This has limited the theoretical advancement of community capacity theory as it relates to CSOs and community development. Using a qualitative case study approach, the authors analyze the outcomes and challenges of implementing community capacity building strategies in an American CSO, and draw on the empirical data to contribute to this theoretical conversation. Interviews, participant observation, and document analysis were used to generate data, and deductive techniques were used for thematic analysis. The results highlight the outcomes of the capacity building strategies and challenges associated with implementation. In addition, the conclusion focuses on theoretical contributions to community capacity theory, namely the role of sport in facilitating inter-community relations across social groups and the link with process models of organizational capacity.  相似文献   
860.
27 children with early onset (less than 4 years) diabetes (EOD), 24 with late onset (greater than 4.0 years) diabetes (LOD), and 30 sibling controls were compared in their performance on tests of intellectual functioning and school achievement. The results indicated that children with EOD, particularly girls, scored lower than the other groups of diabetic children and siblings on tests of visuospatial but not verbal ability. Many of the children with EOD were also having difficulty at school, and a number were currently receiving special education. Diabetic children with earlier onset had more hypoglycemic convulsions than those with later onset. Regression analyses revealed that duration of illness, age of onset, and hypoglycemic convulsions significantly predicted spatial ability.  相似文献   
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