91 resultados para 325-M0055A


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Despite calls that the school science curriculum should develop among students an ability to understand and respond critically to science-related media reports, very little research has been directed toward an important matter relevant to that aim, namely, how children and young people, untutored, react to science in the news. This study sought, in the context of media coverage of the debate surrounding the planetary status of Pluto, to explore this issue. A questionnaire, completed by 350 students aged between eight and 18, showed just over half of the children and young people were able to write relevantly about the subject though it was the gist not the detail of the story they recounted. There was evidence, nonetheless, that this media-acquired information functioned as active rather than passive knowledge. Students demonstrated relatively few misconceptions and those presented were predominately pre-existing rather than media-derived. As with the wider public, many of the children and young people held strong opinions on Pluto's loss of planethood. Such responses diminished with age, however, with older students expressing a degree of indifference. The paper concludes with a discussion of some implications of the research findings for science instruction.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Studies in sensory neuroscience reveal the critical importance of accurate sensory perception for cognitive development. There is considerable debate concerning the possible sensory correlates of phonological processing, the primary cognitive risk factor for developmental dyslexia. Across languages, children with dyslexia have a specific difficulty with the neural representation of the phonological structure of speech. The identification of a robust sensory marker of phonological difficulties would enable early identification of risk for developmental dyslexia and early targeted intervention. Here, we explore whether phonological processing difficulties are associated with difficulties in processing acoustic cues to speech rhythm. Speech rhythm is used across languages by infants to segment the speech stream into words and syllables. Early difficulties in perceiving auditory sensory cues to speech rhythm and prosody could lead developmentally to impairments in phonology. We compared matched samples of children with and without dyslexia, learning three very different spoken and written languages, English, Spanish, and Chinese. The key sensory cue measured was rate of onset of the amplitude envelope (rise time), known to be critical for the rhythmic timing of speech. Despite phonological and orthographic differences, for each language, rise time sensitivity was a significant predictor of phonological awareness, and rise time was the only consistent predictor of reading acquisition. The data support a language-universal theory of the neural basis of developmental dyslexia on the basis of rhythmic perception and syllable segmentation. They also suggest that novel remediation strategies on the basis of rhythm and music may offer benefits for phonological and linguistic development.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Jellyfish are one of the most abundant and conspicuous members of our coastal marine fauna and are now known to play major trophic roles in marine systems. However, little is known about the movements and behaviour of individuals. We equipped individual compass jellyfish (Chrysaora hysoscella) (n = 15) off the Dingle coast, Ireland, with miniature time-depth recorders to log their depth over periods of a few hours. Vertical movements were extensive, with all jellyfish changing their depth during tracking. A range of vertical movements were seen including initial diving from the surface down to a maximum of 29.6 m after device attachment, some jellyfish remaining near the bottom, some moving up and down in mid-water and some moving back near the surface. These results show that jellyfish actively reposition themselves in the water column over small time-scales and open the way for more extensive studies equipping jellyfish with electronic tags.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Voice over IP (VoIP) has experienced a tremendous growth over the last few years and is now widely used among the population and for business purposes. The security of such VoIP systems is often assumed, creating a false sense of privacy. This paper investigates in detail the leakage of information from Skype, a widely used and protected VoIP application. Experiments have shown that isolated phonemes can be classified and given sentences identified. By using the dynamic time warping (DTW) algorithm, frequently used in speech processing, an accuracy of 60% can be reached. The results can be further improved by choosing specific training data and reach an accuracy of 83% under specific conditions. The initial results being speaker dependent, an approach involving the Kalman filter is proposed to extract the kernel of all training signals.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objective. The authors examined bidirectional relations between youth exposure to sectarian and nonsectarian antisocial behavior and mothers' efforts to control youths' exposure to community violence in Belfast, Northern Ireland. Design. Mother-child dyads (N = 773) were interviewed in their homes twice over 2 years regarding youths' exposure to sectarian and nonsectarian community antisocial behavior and mothers' use of control strategies, including behavioral and psychological control. Results. Youths' exposure to nonsectarian antisocial behavior was related to increases in mothers' use of behavioral and psychological control strategies over time, controlling for earlier levels of these constructs. Reflecting bidirectional relations, mothers' behavioral control strategies were associated with youths' reduced exposure to nonsectarian and sectarian antisocial behavior over time, whereas psychological control was not related to reduced exposure. Conclusion. Only nonsectarian community violence was associated longitudinally with mothers' increased use of control strategies, and only behavioral control strategies were effective in reducing youths' exposure to community antisocial behavior, including sectarian and nonsectarian antisocial behavior.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We describe a detailed depth-and time-dependent model of the molecular cloud associated with the ultracompact H II region G 34.3+0.15. Previous work on observations of NH3 and CS indicates that the molecular cloud has three distinct physical components:- an ultracompact hot core, a compact hot core and an extended halo. We have used the physical parameters derived from these observations as input to our detailed chemical kinetic modelling. The results of the model calculations are discussed with reference to the different chemistries occuring in each component and are compared with abundances derived from our recent spectral line survey of G 34.3+0.15 (Paper I).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The dyes Nile Blue (C I Basic Blue 12) and Thionine (C I 52000) were examined in both ionic and neutral forms in different solvents using NMR and UV-visible spectroscopy to firmly establish the structures of the molecules and to assess the nature and extent of their aggregation H-1 and C-13 NMR assignments and chemical shift data were used together with nuclear Overhauser effect information to propose a self-assembly structure These data were supplemented with variable temperature dilution and diffusion-based experimental results using H-1 NMR spectroscopy thereby enabling extended aggregate structures to be assessed in terms of the relative strength of self-association and the extent to which extended aggregates could form (C) 2010 Elsevier Ltd All rights reserved