Teaching referents and the warrants used to test the viability of students' mental models: Is there a link?

From a constructivist perspective, learners construct viable knowledge rather than acquire representations of truth. The warrants of authority, coherence, and empirical evidence are identified as means by which the viability of knowledge claims can be established by learners. In this interpretive study, we examined which warrants were invoked by Grade 8 science classroom participants in their daily interactions, and whether these were linked to particular teaching referents. We found that when the teacher embraced a content exposure referent at the expense of constructivism, the warrant of authority dominated interactions. The students' alternative conceptions and mental models were not explored appropriately. Instead, students most frequently were expected to accept the voice of authority uncritically. By such actions students were restrained from meaningful learning. © 1997 John Wiley & Sons, Inc. J Res Sci Teach 34: 223–238, 1997.     

Mapping the literature of dental assisting.

The purpose of this study was to identify core journals and the databases that provide access to these journals for the field of dental assisting. This study was completed as a part of the Medical Library Association (MLA) Nursing and Allied Health Resources Section's project to map the literature of allied health. There were three original journals selected for analysis using the prescribed methodology, Dental Assistant, the journal of the American Dental Assistants Association; Journal of the CDAA, the journal of the Canadian Dental Assistants' Association; and Dental Teamwork, published by the American Dental Association. Dental Teamwork ceased publication in December 1996; however, it was considered a necessary part of the analysis due to its extensive coverage of dental assisting as well as its numerous scientific articles with references. In Dental Assistant, there were 16 source articles, containing 206 citations. In Dental Teamwork, there were 31 source articles with 308 citations. In Journal of the CDAA, there were only 3 source articles with 14 citations. Bradford's Law of Scattering was applied to the journal citations. Four databases, MEDLINE, the Cumulative Index to Nursing and Allied Health Literature, EMBASE/Excerpta Medica, and HEALTH were analyzed for their coverage of these cited journals. This study may encourage the dental assisting profession to take a close look at its existing journals and to consider enhancing the content of these journals or the publication of additional journals in the field. Dental assistants of today need substantive literature that deals with all aspects of their chosen profession in order to meet the challenges of providing dental health care in the future.     

Metalinguistic awareness and reading strategies

Annals of Dyslexia -     

DNA methylation profiling in nanochannels

We report the profiling of the 5-methyl cytosine distribution within single genomic-sized DNA molecules at a gene-relevant resolution. This method linearizes and stretches DNA molecules by confinement to channels with a dimension of about 250×200 nm(2). The methylation state is detected using fluorescently labeled methyl-CpG binding domain proteins (MBD), with high signal contrast and low background. DNA barcodes consisting of methylated and non-methylated segments are generated, with both short and long concatemers demonstrating spatially resolved MBD binding. The resolution of the technique is better than 10 kbp, and single-molecule read-lengths exceeding 140 kbp have been achieved.