4,981 research outputs found
UV Upturn in Elliptical Galaxies: Theory
The UV upturn is the rising flux with decreasing wavelength between the Lyman
limit and 2500\AA found virtually in all bright spheroidal galaxies. It has
been a mystery ever since it was first detected by the OAO-2 space telescope
(Code & Welch 1979) because such old metal-rich populations were not expected
to contain any substantial number of hot stars. It was confirmed by following
space missions, ANS (de Boer 1982), IUE (Bertola et al. 1982) and HUT (Brown et
al. 1997). The positive correlation between the UV-to-optical colour (i.e., the
strength of the UV upturn) and the Mg2 line strength found by Burstein et al.
(1987) through IUE observations has urged theorists to construct novel
scenarios in which metal-rich () old ( a few Gyr)
stars become UV bright (Greggio & Renzini 1990; Horch et al. 1992). Also
interesting was to find using HUT that, regardless of the UV strength, the UV
spectral slopes at 1000--2000\AA in the six UV bright galaxies were nearly
identical suggesting a very small range of temperatures of the UV sources in
these galaxies (Brown et al. 1997), which corresponds to K. This, together with other evidence, effectively ruled out
young stars as the main driver of the UV upturn. A good review on the
observational side of the story is given in the next article by Tom Brown, as
well as in the recent articles of Greggio & Renzini (1999) and O'Connell
(1999).Comment: 6 figures; belated paper from Keele Conferenc
Conceptualizing professional development in mathematics: elements of a model
This theoretical paper discusses the concept of models for mathematics professional development. After examining the related literature, we propose a definition of this concept that includes four elements: goals, theories, contexts, and structure. We present aspects of professional development that comprise each element
Mind and autism spectrum disorders: A Theory-of-Mind continuum model and typology developed from Theory-of Mind as subjectively experienced and objectively understood
This study defines Theory-of-Mind as the ability to experience one’s own mind and understand the minds of others to the extent necessary to make sense of human behaviour and the world. Since the concept of Theory-of-Mind was first applied to people with ASD (Baron-Cohen, Leslie & Frith, 1985), lack of Theory-of-Mind has been used to explain their cognitive difficulties (National Research Council, 2003), along with social, communicative and imaginative impairments (Frith, Happé & Siddons, 1994). Previous studies have tended to think of Theory-of-Mind in terms of a simple binary of deficit or credit; to exclude the voices of people with ASD; to emphasise the cognitive aspects of Theory-of-Mind over its affective aspects; and to emphasise understanding the minds of others over experiencing one’s own mind. This study aims to address these issues by investigating Theory-of-Mind as subjectively experienced by students with ASD and objectively understood by their teachers. It is the first attempt in the study of Theory-of-Mind to include the voices of individuals with ASD along with the professional views of their teachers. This study takes an interdisciplinary approach, supported by philosophy of mind and special education. A grounded theory approach and a mixed methods research design combine to build and strengthen a theory of Theory-of-Mind. For Theory-of-Mind as subjectively experienced, 20 senior secondary and post secondary school students with ASD from Republic of Korea were interviewed and student-produced documents were reviewed to draw out their inner experiences. The Korean Wechsler Adult Intelligence Scale and the Korean Vineland Social Maturity Scale were employed to assess IQ and social competence. For Theory-of-Mind as objectively understood, their teachers’ beliefs regarding their students with ASD were sought through in-depth interviews, a review of teacher-produced documents and administration of a newly developed Teacher Questionnaire. This study reports differences between Theory-of-Mind as subjectively experienced and objectively observed, and variations within the components of Theory-of-Mind. The role of imagination in Theory-of-Mind and the relationships between Theory-of-Mind components, IQ and social competence are discussed. As a result, a Theory-of-Mind continuum model and Theory-of-Mind Typology is proposed
- …