Students' perception and learning practices about online timed take-home examinations and the factors affecting students' learning practices in the presence of Covid-19 have largely been unexplored. ...Nine students of arts, business and science sub-degree programmes participated in this study. Semi-structured interviews and reflective journals were used to collect data. Findings indicate students' perceptions cover types and level of difficulty of examination questions, the use of online platforms, time spans, benefits and challenges of take-home examinations. The learning practices encompassed in-class online learning, after-class learning commitments and the responses during take-home examinations. The help of instructors, the participants' personal characteristics, the assessment design and online platforms are factors that affected the participants' learning practices. Pedagogical implications and future studies of take-home examinations are discussed.
The impact of evolving feedback ecology on students' feedback literacy development remains underexplored. This study examined the effects of transitioning from secondary to higher education on ...students' conceptions and practices of feedback literacy. The research involved 35 first-year associate's degree students from various disciplines at a Hong Kong higher education institution. Through semi-structured interviews and reflective journals, changes and continuities in students' feedback literacy were explored, alongside the critical ecological factors influencing these transformations. Three types of feedback literacy emerged - passive, bidirectional and self-regulated - representing varying degrees of student autonomy and teacher involvement in the feedback process. The study also identified contextual factors (e.g. continuous assessments, teacher-student consultation sessions, alternative communication and group dynamics) and individual factors that influenced students' feedback practices. The implications of these findings for cultivating conducive feedback ecology and enhancing student feedback literacy are discussed.
The emergence of SARS-CoV-2 variants of concern (VOCs) and variants of interest (VOIs) with decreased susceptibility to neutralization has generated interest in assessments of booster doses and ...variant-specific vaccines. Clinical trial participants who received a two-dose primary series of the COVID-19 vaccine mRNA-1273 approximately 6 months earlier entered an open-label phase 2a study ( NCT04405076 ) to evaluate the primary objectives of safety and immunogenicity of a single booster dose of mRNA-1273 or variant-modified mRNAs, including multivalent mRNA-1273.211. As the trial is currently ongoing, this exploratory interim analysis includes preliminary descriptive results only of four booster groups (n = 20 per group). Immediately before the booster dose, neutralizing antibodies against wild-type D614G virus had waned (P < 0.0001) relative to peak titers against wild-type D614G measured 1 month after the primary series, and neutralization titers against B.1.351 (Beta), P.1 (Gamma) and B.1.617.2 (Delta) VOCs were either low or undetectable. Both the mRNA-1273 booster and variant-modified boosters were safe and well-tolerated. All boosters, including mRNA-1273, numerically increased neutralization titers against the wild-type D614G virus compared to peak titers against wild-type D614G measured 1 month after the primary series; significant increases were observed for mRNA-1273 and mRNA-1273.211 (P < 0.0001). In addition, all boosters increased neutralization titers against key VOCs and VOIs, including B.1.351, P.1. and B.1.617.2, that were statistically equivalent to peak titers measured after the primary vaccine series against wild-type D614G virus, with superior titers against some VOIs. This trial is ongoing.
This study aims to explore undergraduates' perceptions of and responses to exemplar-based dialogic feedback. Forty-eight undergraduate teacher education students of Chinese language, science and ...social science participated. Semi-structured interviews, classroom observations and reflective journals were used to collect data. Students reported both benefits and challenges of exemplar-based discussion, which depends largely on the quality of the dialogic feedback. Three patterns of response were identified in the discussion: no response, moderate response and active response. Three factors influenced their responses: personal qualities, the availability of a supportive environment and teacher scaffolding. Reconceptualisation of feedback and pedagogical implications are discussed.
Substantial research indicates that students' beliefs mediate learning strategies. Nevertheless, students' strategy-related beliefs about feedback and their mediation on strategies to act on feedback ...are insufficiently addressed. This case study aimed to examine: (1) students' strategy-related beliefs about feedback in L2 writing and (2) how beliefs mediated students' actions when a feedback intervention was implemented to facilitate students' use of feedback strategies. Data were collected from semi-structured interviews and reflective journals from 10 Year-1 participants who studied in an associate degree programme at a higher education institute in Hong Kong. Students' strategy-related beliefs about feedback encompass the evaluation of strategies about: (1) understanding feedback, (2) addressing areas for improvement, (3) seeking feedback, and (4) implementing feedback. Nine participants adopted a more comprehensive range of strategies to act on feedback consistent with their strategy-related beliefs. One participant, however, did not appreciate and use feedback. Pedagogical implications are discussed.
Neuroblastoma, a frequently occurring solid tumour in children, remains a therapeutic challenge as existing imaging tools are inadequate for proper and accurate diagnosis, resulting in treatment ...failures. Nanoparticles have recently been introduced to the field of cancer research and promise remarkable improvements in diagnostics, targeting and drug delivery. Among these nanoparticles, quantum dots (QDs) are highly appealing due to their manipulatable surfaces, yielding multifunctional QDs applicable in different biological models. The biocompatibility of these QDs, however, remains questionable.
We show here that QD surface modifications with N-acetylcysteine (NAC) alter QD physical and biological properties. In human neuroblastoma (SH-SY5Y) cells, NAC modified QDs were internalized to a lesser extent and were less cytotoxic than unmodified QDs. Cytotoxicity was correlated with Fas upregulation on the surface of treated cells. Alongside the increased expression of Fas, QD treated cells had increased membrane lipid peroxidation, as measured by the fluorescent BODIPY-C11 dye. Moreover, peroxidized lipids were detected at the mitochondrial level, contributing to the impairment of mitochondrial functions as shown by the MTT reduction assay and imaged with confocal microscopy using the fluorescent JC-1 dye.
QD core and surface compositions, as well as QD stability, all influence nanoparticle internalization and the consequent cytotoxicity. Cadmium telluride QD-induced toxicity involves the upregulation of the Fas receptor and lipid peroxidation, leading to impaired neuroblastoma cell functions. Further improvements of nanoparticles and our understanding of the underlying mechanisms of QD-toxicity are critical for the development of new nanotherapeutics or diagnostics in nano-oncology.
The staggering array of nanotechnological products, found in our environment and those applicable in medicine, has stimulated a growing interest in examining their long-term impact on genetic and ...epigenetic processes. We examined here the epigenomic and genotoxic response to cadmium telluride quantum dots (QDs) in human breast carcinoma cells. QD treatment induced global hypoacetylation implying a global epigenomic response. The ubiquitous responder to genotoxic stress, p53, was activated by QD challenge resulting in translocation of p53, with subsequent upregulation of downstream targets
Puma
and
Noxa
. Consequential decrease in cell viability was in part prevented by the p53 inhibitor pifithrin-α, suggesting that p53 translocation contributes to QD-induced cytotoxicity. These findings suggest three levels of nanoparticle-induced cellular changes: non-genomic, genomic and epigenetic. Epigenetic changes may have long-term effects on gene expression programming long after the initial signal has been removed, and if these changes remain undetected, it could lead to long-term untoward effects in biological systems. These studies suggest that aside from genotoxic effects, nanoparticles could cause more subtle epigenetic changes which merit thorough examination of environmental nanoparticles and novel candidate nanomaterials for medical applications.
Infection with influenza virus induces antibodies to the viral surface glycoproteins hemagglutinin and neuraminidase, and these responses can be broadly protective. To assess the breadth and ...magnitude of antibody responses, we sequentially infected mice, guinea pigs and ferrets with divergent H1N1 or H3N2 subtypes of influenza virus. We measured antibody responses by ELISA of an extensive panel of recombinant glycoproteins representing the viral diversity in nature. Guinea pigs developed high titers of broadly cross-reactive antibodies; mice and ferrets exhibited narrower humoral responses. Then, we compared antibody responses after infection of humans with influenza virus H1N1 or H3N2 and found markedly broad responses and cogent evidence for 'original antigenic sin'. This work will inform the design of universal vaccines against influenza virus and can guide pandemic-preparedness efforts directed against emerging influenza viruses.
This two-year longitudinal study explores whether a professional learning community (PLC) helps shift language teachers' beliefs about implementing play-based learning. Ten practitioners from a ...preschool participated in this case study. Data were collected through interviews and observations of participants' practices engaged in the PLC. The emerged PLC characteristics found transform teachers' beliefs that are (1) shared goals, (2) learning activities and (3) collegiality. All participants had different conceptual changes about implementing play-based learning towards a child-centred approach. The emerged change categories are the prime concern in lesson planning, learning objectives, types of lesson plans, instructional pedagogies, learning activities and teaching materials. Implications for teacher development are discussed.
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