The role of content-rich visuals in the L2 academic listening assessment construct

Despite the growing recognition that second language (L2) listening is a skill incorporating the ability to process visual information along with the auditory stimulus, standardized L2 listening assessments have been predominantly operationalizing this language skill as visual-free (Buck, 2001; Kang, Gutierrez Arvizu, Chaipuapae, & Lesnov, 2016). This study has attempted to clarify the nature of the L2 academic listening assessment construct regarding the role of visual information. This goal was achieved by developing an interpretive argument for including video-based visuals in L2 academic listening tests. Particular attention was paid to the role of content-related visuals that provided graphical illustration, description, or explanation of the auditory listening message. Using Kane’s validity framework, the explanation inference was of primary concern to this study because it is used to justify the measured construct (Kane, 1992; 2004; 2006; 2013). The explanation inference was supported by two types of evidence. First, the performances of 143 English as a second language (ESL) and English as a foreign language (EFL) students on an academic English listening comprehension test were quantitatively analyzed for the effect of delivery mode (i.e., audio-only vs video-based) and its relationships with test-takers’ listening proficiency (i.e., lower vs higher), item video-dependence (i.e., whether or not an item was cued by video), item type (i.e., local vs global), and viewing behavior (self-reported on a scale from 1-did not watch the video to 5-watched all of the video). Analyses were based on both classical test theory (i.e., ANOVA and correlations) and item response theory (i.e., Rasch analysis). In the video-based version of the test, content-rich videos were used, defined as videos containing relevant graphical content-related visual cues for 60% of the video length. The findings showed that video-dependent items were easier with videos than without for both lower-level and higher-level test-takers, regardless of item type. Video-independent items were unexpectedly harder with videos in general. In particular, video-independent global items were harder in the video-based mode than in the audio-only mode for lower-level test-takers. Viewing behavior had a weak positive relationship with listening comprehension, regardless of proficiency. Second, stakeholders’ perceptions about using content-rich videos were investigated. Using a questionnaire, the same 143 test-takers provided their perceptions of test difficulty, motivation towards listening, listening authenticity, and whether content-rich videos should be used in high-stakes academic listening tests. The effects of mode and proficiency on these perceptions were examined. Similarly, 310 ESL and EFL teachers provided their opinions about the effects of content-rich videos on listening difficulty, motivation, authenticity, and using content-rich videos in L2 listening tests. The effects of teachers’ background (i.e., professional location, education level, and teaching-related experience) on their perceptions were examined. Test-takers found the video-based mode easier than the audio-only mode; however, their perceptions of motivation, authenticity, and using videos in tests were not affected by mode. Regarding video use perceptions, test-takers were in favor of including content-rich videos in L2 academic listening tests. Teachers were more favorable towards the video-based mode than the audio-only mode in terms of listening difficulty, motivation, authenticity, and using videos in L2 academic listening tests. The study has discussed how these findings supported the interpretive argument for including content-rich video-based visual information into the assessment construct of L2 academic listening comprehension. Challenges revealed by the findings were also addressed, with limitations acknowledged. The study also offered theoretical and practical implications for the field of L2 assessment. As its primary implication, the study recommends that test developers start using content-rich visual information in L2 academic listening tests

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial

Background: Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke. Methods: We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515. Findings: Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p<0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (<1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (<1%) deaths in the albiglutide group. Interpretation: In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes. Funding: GlaxoSmithKline

Using Videos in ESL Listening Achievement Tests: Effects on Difficulty

The question as to whether an assessment construct of second language (L2) listening comprehension should include the decoding of visual information remains unanswered (see Buck, 2001; Ockey, 2007). This study aimed to fill this gap by investigating how audio-only and video-enhanced delivery formats of listening passages compared in terms of difficulty for English as a second language (ESL) students. It utilized students’ performance on listening achievement tests developed by the researcher. The participants were 60 low- and high-proficiency ESL students enrolled in an American intensive English program. The participants’ scores on the achievement tests were used to compare the difficulty of items of different formats and determine whether this difficulty related to video type (context versus content) and students’ proficiency level. The findings suggested that, at least for higher-level students, listening testlets enhanced with videos containing mostly content-related visuals were significantly easier than their audio-only counterparts were. On the contrary, the inclusion of videos with mostly context visuals did not affect the difficulty of testlets in any proficiency category. The findings are discussed in terms of their practical significance for ESL teachers as well as theoretical implications for the field of ESL listening assessment