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Publication On solvable septics(2005-01-07) LAU JING FENG; MATHEMATICS; LANG MONG LUNGThe problem of solving the general irreducible polynomial in one variable and expressing its roots in radicals has been proposed ages ago. Since then the case of solving general quadratics, cubics and quartics has been solved and it took a few centuries before Abel and Galois demonstrated the impossibility to solve general equations of degree higher than 4. In two recent papers [D] and [H], Dummit and respectively Hagedorn provide methodologies to solve the general solvable quintic and sextic. In this thesis, we shall adopt the techniques in [D] to give a qualitative description of solving solvable irreducible polynomials of arbitrary prime degree and apply these results to solve for two of the roots of x^7+x^6-12x^5-7x^4+28x^3+14x^2-9x+1=0 which can be used to express cos 2 pi/29 in radicals.References[D] D. S. Dummit, Solving Solvable Quintics, Mathematics of Computation, Volume 57, Issue 195, 387-401, 1991.[H] T. R. Hagedorn, General Formulas for Solving Solvable Sextic Equations, Journal of Algebra, Volume 233, Issue 2, 704-757, 2000.Publication MICRORNA-128 REGULATES THE PROLIFERATION AND NEUROGENESIS OF NEURAL PRECURSORS BY TARGETING PERICENTRIOLAR MATERIAL 1 (PCM1) IN THE DEVELOPING NEOCORTEX(2016-07-27) PAUL JONG KIM; DEAN'S OFFICE (DUKE-NUS MEDICAL SCHOOL)Formation of the neocortex during brain development requires coordinated transition of cell division from one that favors progenitor proliferation to that of neuronal differentiation undertaken by neural stem cells (NSCs). Disruption to this process may underlie structural changes in the brain associated with neuropsychiatric disorders including autism spectrum disorders (ASDs). Evidence that suggests microRNA (miR)-128, shown to be dysregulated in ASDs, to be a key regulator of NSC division is presented in this thesis. Manipulation of miR-128 in embryonic NSCs is carried out both in vitro and in vivo, in which upregulation increases neurogenesis and inhibits progenitor proliferation while downregulation has the opposite effect. Furthermore, pericentriolar material 1 (PCM1) is identified as the downstream molecular target of miR-128 that mediates the regulatory effect of the microRNA. Overexpression of miR-128 suppresses PCM1 at both mRNA and protein levels, and direct knockdown of PCM1 produces a phenocopy of miR-128 overexpression in NSCs. Finally, concomitant induction of PCM1 and miR-128 overexpression in NSCs rescued the phenotype associated with miR-128 overexpression, both in vitro and in vivo. Taken together, these results demonstrate a novel mechanism by which miR-128 regulates the proliferation and differentiation of NSCs in the developing neocortex.Publication INVESTIGATING THE ROLE OF INNATE LYMPHOID CELLS AND Tc17 IN HUMAN HEPATOCELLULAR CARCINOMA(2023-01-17) LEE YUN HUA; DEAN'S OFFICE (MEDICINE); Haiyan Liu; Suk Peng Chew; Herbert SchwarzPublication THE EFFECT OF PARENTING FACTORS ON SHAME AND GUILT IN SINGAPOREAN PRE-SCHOOLERS(2019-11-01) CARMEN CHEW HOOI LING; PSYCHOLOGY; MATTHEW LIM SHENG MIANShame and guilt are self-conscious emotions developed through an understanding of moral contracts, moral reasoning and fairness (Kegan, 1982; Selman, 1980). These emotions emerge early in life and are associated with various forms of psychopathology (Luby et al., 2009). Recent evidence suggests that parental psychopathology and parenting style can predict shame and guilt in young children. This study explored the relationships between the aforementioned parental factors and shame and guilt in a community sample of 80 Singaporean pre-schoolers and their parents via online questionnaires. This study examined different aspects of children’s shame and guilt by distinguishing between maladaptive shame/guilt feelings and adaptive guilt reparations. It was hypothesised that authoritarian and permissive parenting, as well as parental depression and anxiety would predict shame/guilt feelings in pre-schoolers. It was also hypothesised that authoritative parenting would predict pre-schoolers guilt reparations. Further, parental psychopathology was hypothesised to moderate the relationship between parenting styles and children’s shame/guilt feelings and guilt reparations. Results indicated that mothers’ permissive parenting led to a decrease in children’s guilt reparations. Father’s depression was also found to amplify the negative impact of permissive parenting on children’s guilt reparations. The empirical and clinical implications of these findings are discussed. To our knowledge, this study is the first to include both mothers and fathers in examining the relationship between multiple parental factors and shame and guilt in Singaporean pre-schoolers.Publication Robust Optimization With Applications In Healthcare Operations Management(2014-08-22) ZHANG MEILIN; DECISION SCIENCES; SIM SOON SUAN, MELVYNThe combination of an increasingly complex world, the vast proliferation of data, and the pressing need to stay one step ahead of competition has sharpened focus on using analytics and optimization for decision making. There is also a need to computationally exploit the wealth of data available in optimization problems by providing a exible framework for modeling uncertainty that incorporates distributional information, while preserving the computational tractability for practical implementation. As motivated by the importance of such a decision making process, I investigate this procedure under robust optimization and extend the ndings into real applications in health care operations management.Publication GENETIC CONNECTIVITY OF FOUR MANGROVE SPECIES FROM THE MALAY PENINSULA(2013-08-12) WEE KIM SHAN; BIOLOGICAL SCIENCES; WEBB, EDWARD LAYMANAs habitat fragmentation and degradation continues to threaten the integrity of genetic connectivity in mangroves, gene flow among populations becomes increasingly important for the maintenance of sufficient genetic diversity and evolutionary potential. In this thesis, I determined the effects of reproductive traits, physical barriers and ocean currents on gene flow in mangroves, by examining the genetic connectivity of four major mangrove species from the Malay Peninsula. My data revealed that the relative genetic connectivity across species reflects their relative propagule dispersal potential, indicating that dispersal traits have a significant influence over gene flow. Comparative analysis across species demonstrated that the peninsula was a differential barrier to gene flow, and that ocean currents are important in defining genetic connectivity. Understanding gene flow in mangroves and the intrinsic and extrinsic factors behind it is crucial in assessing the genetic susceptibility of mangroves towards and the potential of recovery from habitat disturbances.Publication Fabrication of Membrane-Electrode-Assembly for Polymer Electrolyte Membrane Fuel Cell(2007-06-19) POH CHEE KOK; PHYSICS; LIN JIANYIThis work aimed to improve the performance of proton exchange membrane fuel cell (PEMFC) through two approaches. One is to improve the methods of fabricating membrane-electrode-assembly. Four different methods were compared. The various aspects of the fabrication have been discussed in details, including the composition, thickness and porosity electrodes, and the compaction force. By optimizing the fabrication parameters the performance of the fuel cell has been enhanced by >50%. The second approach is the application of citric acid modified carbon nanotubes as catalyst support for PEMFC. The novel catalyst materials demonstrated better performance compared to catalyst supported on commercial carbon blacks in methanol oxidation and PEMFC testing. The experimental studies demonstrated that the performance depends on electrochemical properties of the catalyst and the physical structure of the electrodes and the performance of PEMFC can be further improved through research on both advanced nano-scale materials and advanced fabrication techniques.Publication CONDUCTING POLYMER NANOPARTICLES WITH PENDANT OXYETHYLENE BRANCHES AND THEIR COLLOIDAL BEHAVIOUR(2001) PAN YONG; CHEMICAL & ENVIRONMENTAL ENGINEERING; HONG LIANGPublication SURVEYS ON THE USAGE OF COMPLEMENTARY AND ALTERNATIVE MEDICINE, HERBAL PRODUCTS IN THE MARKET AND THE EFFECTS OF GINSENOSIDE RG1 ON MEDIAL PREFRONTAL CORTEX(2014-08-15) MEHDY GHAEMINIA; PHARMACOLOGY; TAN CHAY HOON; KOH HWEE LINGUsage of CAM has prominent impact on users? health. Here, this fact was studied by getting the information from community and expanding the research to the laboratory. Analyzing the CAM usage among older adults revealed its prevalence as 54% (the commonest type was herbal medicine). Composite CAM and qigong usages showed protection against cognitive decline. By a telephone-based interview, we found three Panax species among the top six herbs used by older adults. Surveying the labels of products containing the words ?Panax? or ?ginseng?, we found Panax ginseng is the commonest ingredient of such products. Finally, the neuroinhibitory effects of a high abundant chemical component of Panax species, Rg1, on medial prefrontal cortex (mPFC) were observed using electrphysiological and histochemical methods. This first report of modulation of mPFC by Rg1 and first report of its possible neuroinhibitory effects may help to explain its anxiolytic and memory enhancing properties.Publication INFLUENCER-GENERATED ORGANIC CONTENT AND FIRM STRATEGIES(2023-06-27) GAO SHIWEN; MARKETING; Wei Shi LimConsumers are now increasingly relying on social media to discover new products and acquire information about product fit. Influencer-generated organic product reviews, as an independent source of product information, play an increasingly important role in consumers’ purchase decisions. We develop a game-theoretic model to examine whether and how an influencer’s organic product review affects a firm’s advertising and pricing strategies, profit, and consumer surplus. We find that in the presence of consumer search, the influencer’s organic content interacts with the firm’s strategies, suggesting new ways for a firm to manage the influencer’s seemingly independent content. Our results also show that the two types of information (influencer’s organic review and firm-created ad) can be complements or substitutes when the firm targets experts only and the cost of review production is low. Our findings complement the existing research on influencers and offer managerial implications for marketers and policymakers.