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1.
ZDM ; 55(1): 95-108, 2023.
Article in English | MEDLINE | ID: mdl-36160181

ABSTRACT

The global COVID-19 pandemic has provided an opportunity to re-examine the possibility of organising virtual conferences in mathematics education, in which the social needs of participants can also be addressed. In this study we investigated the future impact that this change may have on the format and nature of mathematics education conferences. The study was conducted in two phases. We used an online questionnaire in which we asked participants to give us some input on the issues above. In the second phase of the project, focus group interviews were conducted with international mathematics education researchers. This study is an exploratory study, in which the sample was not developed in a way that could generate comparisons. The aim of the study was to raise possibilities about what may be the future of mathematics education conferences. Findings indicate that although academics are pro-actively thinking about alternative conference formats, the proven value of face-to-face conferences is still very real, showing that it is too early for us to have a clear vision of the future format of academic conferences.

2.
Educ Stud Math ; 108(1-2): 183-200, 2021.
Article in English | MEDLINE | ID: mdl-34934226

ABSTRACT

Visual displays in the news media become critical during escalating events such as the COVID-19 pandemic, as they facilitate the communication of complex information to the public. This article investigates the use of graphs in Korea's news media during the COVID-19 outbreak. We selected 12 dates that represent turning points in the outbreak of the disease and collected news stories including graphs from seven Korean daily newspapers issued on those dates. First, we analyzed the usage of graphs in COVID-19 news stories. Quantitative analysis of the types and frequency of graphs used in COVID-19 news stories and qualitative analysis of the content of news stories containing graphs were conducted. Second, we identified cases in which readers may be biased by the mathematical misuse of graphs in the news stories covering COVID-19. The implications of these findings for future teaching and learning of graph literacy in school mathematics courses are discussed.

3.
Appl Biochem Biotechnol ; 166(7): 1843-55, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22371063

ABSTRACT

Fucoxanthin, one of the main marine carotenoids, is abundant in macro- and microalgae. Here, fucoxanthin was isolated and structurally identified as the major carotenoid in the diatom Phaeodactylum tricornutum through chromatographic and spectroscopic methods, such as liquid chromatography-positive-ion atmospheric pressure chemical ionization/mass spectroscopy and nuclear magnetic resonance. This pigment was quantified by reverse-phase high-performance liquid chromatography, and a number of extraction procedures were assessed to investigate the effect of solvent type, extraction time, temperature, and extraction method (maceration, ultrasound-assisted extraction, Soxhlet extraction, and pressurized liquid extraction). Among the investigated solvents, ethanol provided the best fucoxanthin extraction yield (15.71 mg/g freeze-dried sample weight). Fucoxanthin content in the extracts produced by the different methods was quite constant (15.42-16.51 mg/g freeze-dried sample weight) but increased steeply based on the percentage of ethanol in water, emphasizing the importance of ethanol in the extraction. The results indicate that P. tricornutum is a rich source of fucoxanthin (at least ten times more abundant than that in macroalgae) that is easily extracted with ethanol, suggesting potential applications in human and animal food, health, and cosmetics.


Subject(s)
Carotenoids/isolation & purification , Diatoms/chemistry , Ethanol/chemistry , Microalgae/chemistry , Xanthophylls/isolation & purification , Chromatography, High Pressure Liquid , Chromatography, Reverse-Phase , Humans , Liquid-Liquid Extraction , Magnetic Resonance Spectroscopy , Pressure , Solvents/chemistry , Sonication , Temperature
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