The aim of the current study is twofold: to examine the effects of input on bilingual adolescents’ long-term second language (L2) outcomes in a minority/foreign language context; and to understand ...the interaction between input and other potential predictors of L2 outcomes, specifically environmental variables, learners’ motivation and language learning aptitude. Participants included 97 Mandarin–English bilingual adolescents in Taiwan who learned English as an L2 between the ages of two to eleven. All participants completed a listening comprehension and a story-telling task in English and two standardized language learning aptitude tests. Participants and their parents filled out a detailed questionnaire providing information about family demographics and in-class and out-of-class L2 input. Correlation and multivariate regression analyses revealed that input played an important role in long-term L2 listening comprehension outcome, but not in speech production outcomes. The results also showed that environmental variables and language learning aptitude significantly predicted long-term L2 listening comprehension and speech production outcomes. Finally, out-of-class L2 input outweighed instructional input and current input outweighed early input. Since most previous research on the role of input in long-term L2 outcomes was conducted in a majority/societal language context, the present study contributes to the topic by specifying the effect of input in L2 acquisition in a minority/foreign language context.
•Switching to computer L2 writing tests from paper may increase test authenticity.•Test-takers’ typing skills has an effect on their computer-based writing scores.•Computer-based ESL writing tests ...may bias against low-income groups.•Increasing school computer access and typing proficiency may mitigate the bias.
An assumption underlying replacing traditional paper-based (PB) writing tests with computer-based (CB) tests is that CB writing tests are more authentic than PB tests (Lessien, 2013). This study tested this assumption by examining the effect of test mode on the situational and interactive authenticity of English as a second language (ESL) writing assessments using an embedded correlational model of mixed-methods design. Sixty international ESL students enrolled at a university in the United States completed two writing tasks in the CB and PB modes. The participants then filled out cognitive processing questionnaires and participated in a post-test interview. All essays were scored by two raters both holistically and analytically. The results indicated higher authenticity for the CB test but also uncovered some concerns with the effect of typing skills on CB test performance. The findings have practical implications for test development, administration policies, and stakeholders in choosing delivery mode for ESL writing assessments.
Technology has become a common medium in high-stakes language testing. Many scholars claimed for a higher authenticity of computer-based (CB) writing tests than paper-based (PB) with little empirical ...evidence (Lessien, 2013). Test authenticity refers to “the degree of correspondence of the characteristics of a given language test task (LTT) to the features of a target language use (TLU) task” (Bachman & Palmer, 1996, p. 23). Test authenticity influences the construct and consequential validity of a test (Bachman & Palmer, 1996; 2010), but no research empirically compared the authenticity of CB and PB writing tests. This study filled this gap by examining the effect of test medium on the situational and interactive authenticity of English as a second language (ESL) writing assessments. Guided by Bachman and Palmer’s (1996) theoretical discussions of authenticity and Liu’s (2005) conceptual model of authenticity, this study examined the authenticity of the CB and PB ESL writing tests using an embedded correlational model of mixed-methods design. The results indicated a higher authenticity of the CB test, but also uncovered some concerns with the effect of typing accuracy on the CB test performance. Qualitative results suggested a need for hearing test-takers' voice in choosing the test mediums. The findings indicated the advantages of the CB test for assessing postsecondary ESL students' writing proficiency for a higher degree of authenticity compared to the traditional PB test. Nevertheless, the study also revealed some potential issues with construct validity, fairness, and consequential validity of the CB test for ESL writing assessments. This study extended test validation practices to include authenticity measurements. The findings have practical implications for test development, administration policies, and stakeholders in choosing test delivery mediums for ESL writing assessments.
Relatively little research has been devoted to examining the predictors of early foreign language learning outcomes despite the global trend of early foreign language instruction. The current study ...focused on two contextual predictors, learners' socio-economic status (SES) and input, both of which have been demonstrated to play a prominent role in first language development and second language (L2) development in an immersion context. The current study also investigated the relationship between SES, input and L2 learning outcomes and the mechanism through which SES influences L2 outcomes. Participants included 97 tenth and eleventh grade students from Taipei, Taiwan. All participants completed a story-telling task and a survey providing information about their language input in middle and high school. Their parents also filled out a survey providing information about their family profile and learner participants' input in preschool/kindergarten and elementary school. Results from the study showed that both SES and input played a role in adolescent learners’ speech production outcomes, but the effects differed by speech dimensions (i.e., accuracy, fluency, and complexity). Although both SES and input predicted L2 speech production outcomes, the two variables were closely related to each other, and the effect of SES was indirect and mediated by input.
Objective： To screen and analyze key express sequence tags （ESTs） which were differentially displayed in every period of SD rats＇ primary hepatic carcinoma and reveal the molecular mechanism of ...carcinogenesis. Methods： Using diethylnitrosamine （DENA） as a cancerigenic agent, animal models with different phases of primary hepatic cancer were constructed in SD rats. Rats were respectively sacrificed at d 14, d 28, d 56, d 77, d 105 and d 112 after the rats received DENA by gavage, then the livers were harvested. One part of the livers was classified according to their pathological changes, while the other was reserved for molecular mechanism studies on hepatocarcinogenesis. The differentially expressed genes were isolated from both normal and morbid tissues by mRNA differential display technique （DDRT-PCR）. After the fragments were sequenced, bioinformatics were .used to analyze the results. Results： Twelve differentially expressed cDNA fragments were obtained. Nine fragments had the homology with known cDNA clones, especially EST-7 was similar to BN/SsNHsdMCW mitochondrion gene and the identity was 100% which suggested EST-7 may be the part of BN/SsNHsdMCW mitochondrion gene. In contrast, other three fragments （EST-1, EST-3 and EST-5） had extremely low identity to any genes registered in GENBANK databases. Conclusions： BN/SsNHsdMCW mitochondrion gene was expressed in different periods of hepatocarcinogenesis. Moreover, EST-I, EST-3 and EST-5 were suggested to contribute to the development of rat hepatocarcinogenesis, and thus may be candidates of new targets of oncogenes or cancer suppressor genes.
The effects of shot peening（SP） and plasma electrolytic oxidation（PEO） on the intergranular corrosion behavior of the novel high strength aluminum alloy 7A85（AA 7A85） were investigated by ...electrochemical polarization and electrochemical impedance tests.The intergranular corrosion mechanism of SP,PEO and PEO combined with sealingtreated AA 7A85 was studied by the metallographic analysis,residual stress testing,X-ray diffractometer analysis and scanning electron microscopy.The results show that AA 7A85-T7452 is very sensitive to intergranular corrosion.SP would significantly improve its intergranular corrosion resistance.This is attributed to the combination action of residual compressive stress and grain refinement.PEO would reduce the largest corrosion depth by 41.6%.Moreover,PEO without sealing did not eliminate the intergranular corrosion due to the existence of the micropores and microcracks in the oxide coating.However,PEO combined with the SiO2sol–gel sealing treatment could effectively protect the AA 7A85-T7452 from intergranular corrosion because of the good corrosion resistance and barrier function of the sealed coating.
Pt supported on mesoporous silica SBA-15 was investigated as a catalyst for low temperature selective catalytic reduction（SCR） of NO by C 3 H 6 in the presence of excess oxygen.The prepared catalysts ...were characterized by means of XRD,BET surface area,TEM,NO-TPD,NO/C 3 H 6-TPO,NH 3-TPD,XPS and 27 Al MAS NMR.The effects of Pt loading amount,O 2 /C 3 H 6 concentration,and incorporation of Al into SBA-15 have been studied.It was found that the removal efficiency increased significantly after Pt loading,but an optimal loading amount was observed.In particular,under an atmosphere of 150 ppm NO,150 ppm C 3 H 6,and 18 vol.% O 2,0.5% Pt/SBA-15 showed remarkably high catalytic performance giving 80.1% NOx reduction and 87.04% C 3 H 6 conversion simultaneously at 140°C.The enhanced SCR activity of Pt/SBA-15 is associated with its outstanding oxidation activities of NO to NO 2 and C 3 H 6 to CO 2 in low temperature range.The research results also suggested that higher concentration of O 2 and higher concentration of C 3 H 6 favored NO removal.The incorporation of Al into SBA-15 improved catalytic performance,which could be ascribed to the enhancement of catalyst surface acidity caused by tetrahedrally coordinated AlO 4.Moreover,the catalysts could be easily reused and possessed good stability.
A 0.5 wt.% Pt/TiO2 catalyst was prepared and used for the low-temperature selective catalytic reduction （SCR） of NO with C3H6 in the presence of excess oxygen. The effects of Pt loading and 02 ...concentration on Pt/TiO2 catalytic performance for low-temperature SCR were investigated. It was found that optimal Pt loading was 0.5 wt.% and excess 02 favored low-temperature SCR of NOx. The mechanism of low-temperature SCR of NO with C3H6 was investigated with respect to the behavior of adsorbed species over Pt/TiO2 at 150~C using in situ DRIFTS. The results indicated that surface nitrosyl species （Pt~＋-NO and Ti3＋-NO） and pt2＋-CO are main reaction intermediates during the interactions of NO, C3H6 and 02. A simplified NO decomposition mechanism for the low-temperature SCR of NO with C3H6 was proposed.
Inventing the World Grant University: Chinese International Students’ Mobilities, Literacies, and Identities, by Fraiberg, S., Wang, X., & You, X. (2017). Boulder, CO: University Press of Colorado. ...x-279 pp. $31.95 (paperback), $25.95 (ebook), $13.00 (30-day ebook rental). Paperback ISBN: 978-1-60732-733-2. EISBN: 978-1-60732-733-2.
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