Dilemmas in examining understanding of nature of science in Vietnam

Scholars proved nature of science (NOS) has made certain contributions to science teaching and learning. Nonetheless, what, how and how much NOS should be integrated in the science curriculum of each country cannot be a benchmark, due to the influence of culture and society. Before employing NOS in a new context, it should be carefully studied. In assessing views of NOS in Vietnam, a developing country with Eastern culture where the NOS is not consider a compulsory learning outcome, there are several issues that researchers and educators should notice to develop an appropriate instrument that can clearly exhibit a NOS view of Vietnamese. They may include: time for the survey; length, content, type, and terms of the questionnaire; Vietnamese epistemology and philosophy; and some other Vietnamese social and cultural aspects. The most important reason for these considerations is that a Vietnamese view of NOS and NOS assessment possibly differs from the Western ideas due to the social and cultural impact. As a result, a Western assessment tool may become less effective in an Eastern context. The suggestions and implications in this study were derived from a prolonged investigation on Vietnamese science teacher educators and student teachers of School of Education, at Can Tho University, a State University in Mekong Delta region, Vietnam.     

False memory for orthographically versus semantically similar words in adolescents with dyslexia: a fuzzy-trace theory perspective

The presented research was conducted in order to investigate the connections between developmental dyslexia and the functioning of verbatim and gist memory traces—assumed in the fuzzy-trace theory. The participants were 71 high school students (33 with dyslexia and 38 without learning difficulties). The modified procedure and multinomial model of Stahl and Klauer (simplified conjoint recognition model) was used to collect and analyze data. Results showed statistically significant differences in four of the model parameters: (a) the probability of verbatim trace recollection upon presentation of orthographically similar stimulus was higher in the control than dyslexia group, (b) the probability of verbatim trace recollection upon presentation of semantically similar stimulus was higher in the control than dyslexia group, (c) the probability of gist trace retrieval upon presentation of semantically similar stimulus was higher in the dyslexia than control group, and (d) the probability of gist trace retrieval upon target stimulus presentation (in the semantic condition) was higher in the control than dyslexia group. The obtained results suggest differences of memory functioning in terms of verbatim and gist trace retrieval between people with and without dyslexia on specific, elementary cognitive processes postulated by the fuzzy-trace theory. These can indicate new approaches in the education of persons with developmental dyslexia, focused on specific impairments and the strengths of their memory functioning.     

A sequential analysis of responses in online debates to postings of students exhibiting high versus low grammar and spelling errors

Given that grammatical and spelling errors have been found to influence perceived competence and credibility in written communication, this study examined how a student’s grammar and spelling errors affect how other students respond to the student’s postings in four online debates hosted in asynchronous threaded discussions. Message-response exchanges were sequentially analyzed to identify patterns in students’ replies to arguments and challenges with counter-challenges, explanations, and evidentiary support posted by students that exhibited low versus high number of grammatical and spelling errors. Although no causal inferences can be drawn from this study, the findings nevertheless suggests that: (a) arguments posted by high-error students are more likely to be challenged than arguments posted by low-error students; (b) exchanges between high-error students can amplify the effects of grammar/spelling errors; and (c) higher levels of argumentation can be achieved by placing students into groups that are heterogeneous in writing skills in general. The findings and methods used in this study lay the groundwork for further research on strategies for managing individual differences in students’ grammar and spelling (and other student behaviors in general) and increasing the level of critical discourse in online discussions.     

The impact of L1 writing system on ESL knowledge of vowel and consonant spellings

Orthographic knowledge, the general ability to learn, store, and use information about the orthographic form of words (Stanovich & West, 1989), is a crucial skill for supporting literacy. Although the development of first language (L1) orthographic awareness is impacted by the characteristics of a learner’s L1 writing system, relatively little is known about what impact the L1 may have on second language (L2) orthographic awareness. In this study, English language learners from three L1s (French, Hebrew, Mandarin Chinese), plus L1 English speakers, were tested on their English spelling knowledge using a word-pseudohomophone discrimination task. In addition to allowing for the cross-linguistic comparisons, items were designed to examine whether learners had differing performance on pseudohomophones (misspellings) that targeted vowels versus consonants. Consistent with previous research (e.g., McBride-Chang, Bialystok, Cong, & Li, 2004), the L1 Chinese speakers had the highest (L2) accuracy, followed by the L1 Hebrew and the L1 French speakers. The participants from non-alphabetic languages (Hebrew and Chinese) had significantly lower accuracy on items with misspellings involving vowels compared to consonants, and the size of the vowel-consonant accuracy difference varied substantially across L1 groups. The results demonstrate that the characteristics of a learner’s L1 writing system, particularly the existence of vowel and consonant graphemes, impact the development of L2 orthographic knowledge and sensitivity to different types of word misspellings.     

Multi-objective aerodynamic optimization design of high-speed train head shape

To improve the aerodynamic performance of high-speed trains (HSTs) running in the open air, a multi-objective aerodynamic optimization design method for the head shape of a HST is proposed in this paper. A parametric model of the HST was established and seven design variables of the head shape were extracted. Sample points and their exact values of optimization objectives were obtained by an optimal Latin hypercube sampling (opt. LHS) plan and computational fluid dynamic (CFD) simulations, respectively. A Kriging surrogate model was constructed based on the sample points and their optimization objectives. Taking the total aerodynamic drag force and the aerodynamic lift force of the tail coach as the optimization objectives, the multi-objective aerodynamic optimization design was performed based on a non-dominated sorting genetic algorithm-II (NSGA-II) and the Kriging model. After optimization, a series of Pareto-optimal head shapes were obtained. An optimal head shape was selected from the Pareto-optimal head shapes, and the aerodynamic performance of the HST with the optimal head shape was compared with that of the original train in conditions with and without crosswinds. Compared with the original train, the total aerodynamic drag force is reduced by 2.61% and the lift force of the tail coach is reduced by 9.90% in conditions without crosswind. Moreover, the optimal train benefits from lower fluctuations in aerodynamic loads in crosswind conditions.     

CIDE gene expression in adipose tissue,liver, and skeletal muscle from obese and lean pigs

The expression of the cell death-inducing DNA fragmentation factor α-like effector (CIDE) family including Cidea, Cideb, and Cidec was significantly increased in mouse and human models of obesity. However, there was less information on these genes’ expression in pigs. Here, we hypothesized that different fat accumulation between lean (Duroc×Landrace×Yorkshire gilts, DLY) and obese (Lantang) pigs was attributed to porcine CIDE-modulating lipid metabolism. Our data showed that Cidea and Cidec were expressed at a high level in adipose tissue, and at a relatively high level in skeletal muscle, whereas Cideb was mainly expressed in the liver in both breeds of pig. Lantang pigs had higher white adipose and skeletal muscle Cidea and Cidec mRNA abundance, and hepatic and muscle Cideb mRNA than DLY pigs. Lipid metabolism-related genes including sterol regulatory element binding protein 1c (SREBP-1c), hepatocyte nuclear factor-4α (HNF-4α), peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), fatty acid synthase (FASN), diacylglycerol O-acyltransferase 1 (DGAT1), and DGAT2 showed a higher expression level in adipose tissue from obese pigs than in that from lean pigs. Lantang pigs exhibited higher mRNA abundance for liver SREBP-1c, HNF-4α, and PGC-1α, and higher skeletal muscle SREBP-1c, HNF-4α, PGC-1α, and DGAT2 expression, as compared with DLY pigs. However, the perlipin2 mRNA levels in adipose tissues, liver, and skeletal muscle were significantly lower in obese pigs than in their lean counterparts. Furthermore, plasma non-esterified fatty acid (NEFA), glucose, and triacylglycerol (TAG) levels were greater in obese pigs than in lean pigs. Finally, data from correlation analysis further found that CIDE mRNA expression was positively correlated with back fat thickness (BFT), abdominal fat mass (AFM), and the levels of NEFA, TAG, and glucose in the two breeds. Collectively, these data revealed that the porcine CIDEs possibly modulated lipid metabolism and contributed to the development of fat deposition and obesity in Lantang pigs.     

Historical Thinking -- and Its Alleged Unnaturalness

Abstract

No articulation of `historical thinking' has been as influential as Sam Wineburg's position, according to which historical thinking is, fundamentally, the recognition of the ways in which the past is different than the present. Wineburg argues, further, that achieving that state is `unnatural.' This paper critiques both of these claims, arguing instead that we should replace a generic conception of historical thinking with one that is much more rooted in the specific practice of the discipline. It is surely necessary for students to learn this practice, but it is not unnatural. Instead, learning to think historically is learning to speak the language of the discipline that we call ‘history.’