Now showing 1 - 10 of 15
  • Publication
    Epstein-Barr viral latent and early antigen serology in nasopharyngeal carcinoma
    Nasopharyngeal carcinoma (NPC) is cancer of the nasopharynx in humans. It is an insidious and often rapidly fatal disease that is rare worldwide, but is very common among the Chinese from southern China and south-east Asia. It is difficult to detect since, in its early stages, patients are asymptomatic. However, NPC detected in its early stages is highly curable through radiation therapy. Clinically, it can be detected by an experienced medical practitioner using fibreoptic endoscopy, computer-assisted tomography or through serological tests. Serological testing detects the presence of specific antibodies to the Epstein-Barr virus, which is a crucial aetiological factor in the pathogenesis of the disease. Current methods include detection by indirect immunofluorescence assay which is laborious, subjective and requires highly-trained personnel, and enzyme-linked immunosorbent assay (ELISA), which can be easily performed by any hospital laboratory.

    The purpose of this project was to characterise the serology to selected latent and early antigens, and assess the diagnostic significance of the presence of such serology in patients with NPC or NPC-associated symptoms, compared to healthy individuals. This data could then be used in developing assays for the early detection of NPC. To this end, a total of four individual viral antigens were developed for use in ELISA. Three were recombinant clones of viral Early Antigens (encoded by BORF2, BaRF1 and BMRF1 opening-reading frames) and one was a peptide epitope of a latent antigen (from the BKRF1 open-reading frame). The recombinant clones were bacterially-expressed as full-length proteins fused to the maltose-binding protein (MBP) from Escherichia coli, purified and subsequently used as antigens in ELISA.

    The relative effectiveness of the various ELISA developed in this project were compared and discussed. The results were very significant, with up to 100% diagnostic sensitivity, achieved through the use of a duplexed ELISA utilising a pair of antigens from the Epstein-Barr virus. One antigen, MBP:BaRF1, was a novel recombinant clone of a previously little-studied protein from the Early Antigen-Restricted complex, and the other was the synthetic peptide of a defined epitope from the important latent antigen, EBNA-1. This perfect detection rate among NPC patients was achieved while maintaining a low rate of false positives among healthy individuals. Another recombinant antigen, MBP:BMRF1, from the Early Antigen-Diffuse complex was found to be useful for the differential diagnosis of NPC from among individuals with NPC-associated symptoms or risk factors. Certain groups of individuals with such symptoms or risk factors were also found to have significant serology to viral proteins and the implications of this are discussed.

    There was also evidence suggesting that serological testing for NPC could also be used as a gauge of the progress and success of treatment. This was in contrast to the commonly used immunofluorescence assay where this is impractical.

    In conclusion, the project was successful and met the objectives set out. The data generated as a result should provide a useful basis for further research and even in the development of commercially-viable assays for the sensitive and early detection of NPC.
      131  21
  • Publication
    Hands-on and minds-on learning of science using a microbial fuel cell
    (Office of Education Research, National Institute of Education, Singapore, 2020) ;
    Sam, Choon Kook
    Inquiry science has always been a focus of our research as science educators although over the years, we have slowly expanded our initial understanding of “inquiry as means” towards better appreciating “inquiry as ends.” Our confidence in and respect of this more comprehensive view manifested itself in my [LYJ] teaching when I mounted an undergraduate course based on Ready, Set, SCIENCE! (RSS) (Michaels, Shouse, & Schweingruber, 2008). Summarizing an earlier reference called Taking Science to School (TSTS), these two books spoke about the erroneous fixation on content mastery in much of science education though this is still a favoured priority everywhere. While some degree of memorization of science facts and concepts is inevitable, science as a robust way of knowing the natural world is badly compromised if learning is left as these levels. As well, simply having more hands-on laboratory activities or practical work in the hope of mimicking the work of scientists does not serve the aims of inculcating student interest or higher -order thinking in science: Students might be able to manage procedural scientific knowledge, manipulate physical objects during practical work or be able to control some variables but utterly disappoint with respect to creating, revising or applying abstract scientific ideas, models, or theories.
    In all likelihood, any form of inquiry pedagogy can achieve most of the desired endpoints in science education (i.e. the cognitive, epistemic & social) in the hands of a skilful teacher although Design-based Inquiry (DBI) appears most apposite given our adoption of the Microbial fuel Cell (MFC) engineering model. Basically, DBI involves the iterative and problem-solving journey of researching, designing, building, and improvement of objects that pulls along knowledge and application of science—constructing a "successful” artifact is the overarching goal of that activity with just-in-time learning of science as both its condition and byproduct. Its benefits are none other than the entire gamut of doing and learning science authentically and it should come as no surprise to hear that engineering/technological design shares a positive inter-dependence with the development of scientific literacy. Engineering design is the analog of scientific inquiry but whether it be in science or design, success and deep learning is often found, paradoxically, through productive failure—in both disciplines “knowing what is wrong matters as much as knowing what is right”.
    The MFC, our vehicle for student inquiry, has been used since 2005 in NIE to teach principles of biochemistry among in-service teachers. In essence, the MFC is a class of fuelcells that employ various microbes and membranes to generate electricity and it shows potential in areas such as the self-powered treatment of wastewater. The biochemical workings of the MFC are not completely known to science thereby offering opportunities to learn science content, process skills, Nature of Science, and other important skills. With this setup that is unfamiliar to most teachers and students, a wide range of scientific variables can be tested to increase the current that can be obtained—the main goal of the inquiry design challenge for students.
      148  18
  • Publication
    Metadata only
    Innovative science and STEM pedagogies in Singapore
    Yeo, Jennifer Ai Choo
    ; ;
    Globalization, changing demographics, and technological advancements are some of the key driving forces of the future. Our students will have to be prepared to face these challenges and seize the opportunities brought about by these forces. Teaching and learning science can no longer be focused on acquisition of knowledge. Instead, a future-ready individual should develop discipline-specific and interdisciplinary ways of problem-solving. Instilling a range of cognitive and meta-cognitive skills such as critical thinking, creativity, and self-regulation, as well as the right attitude and values such as motivation, trust, respect for life, and diversity, become key elements of science learning. To achieve these learning goals, the Singapore Science Curriculum has made scientific inquiry as its pedagogical underpinning. Structures have been put in place to encourage teachers to try out different inquiry-based activities that develop these twenty-first century competencies. This chapter presents three innovative science and STEM learning approaches – image-to-writing approach (a model-based inquiry), spiral model of collaborative knowledge improvement (an argumentation approach), and microbial fuel cell (a design-based pedagogy) – adopted by science teachers to prepare their charges for the future and discusses how these pedagogical approaches contribute to the development of these competencies.