Fluorescence and photodegradation of Xuan paper: The photostability of traditional Chinese handmade paper

Xuan paper is a type of Chinese handmade paper produced for traditional calligraphy and painting in China since the Tang Dynasty (618–907 AD), and is therefore an important cultural heritage material. In this study, the fluorescence and photochemical properties of Xuan paper were investigated. Xuan paper exhibits auto-fluorescence in the blue spectral range (450–500 nm) and UVA photolysis of the paper resulted in a substantial reduction in the blue fluorescence together with the formation of chromophores absorbing in the visible spectrum, resulting in photoyellowing of the paper. A more significant yellowing of paper was observed when irradiated in the dry state than under wet conditions. The associated photogeneration of hydrogen peroxide and superoxide from three types of Xuan paper samples during irradiation showed a correlation between the yields of reactive oxygen species and their relative yellowing rates. The results are interpreted in terms of sensitised photooxidation via a mechanism of electron transfer involving the fluorophores in their excited singlet states being responsible for the photodegradation of Xuan paper. SEM/EDS analyses were performed on the Xuan paper samples to investigate their morphological and elemental characteristics. Silica-containing fibres characteristic of a special rice straw that grows in siliceous soil were observed in all types of Xuan paper. Micron-sized calcium precipitates possibly formed from the “lime-steaming” manufacture process were shown to protect against the acidification of paper during accelerated thermal ageing.     

Strategies in assessing the need for updating evidence-based guidelines for six clinical topics: an exploration of two search methodologies

BACKGROUND: Because of the expense of updating practice guidelines, recent attention has focused on approaches that can reliably assess any updating required. Shekelle et al. (Journal of the American Medical Association 2001, 286, 1461-7) proposed using limited literature searches with expert involvement to reduce resources used in assessing whether a guideline needs updating. OBJECTIVES: This study compared Shekelle's method and the traditional systematic review method regarding comprehensiveness and effort. METHODS: Two research teams translated critical key questions on screening test treatments and outcomes to Medical Subjects Headings (MeSH) and search strategies. They refined Shekelle's method over three iterations, seeking greater efficiency. Using both methods independently, teams assessed the need to update six topics from the 1996 Guide to Clinical Preventive Services (US Preventive Services Task Force). Outcomes included completeness of study identification, importance of missed studies and effort involved. RESULTS: The revised review approach produced fewer citations than the traditional approach and saved time, identifying fewer eligible studies than the traditional approach. None of the studies missed was rated important by the experts consulted. CONCLUSIONS: The revised review approach provides an acceptable method for judging whether a guideline requires updating. Librarians were an integral part of the research process that streamlined the searches.     

Classroom Questioning with Immediate Electronic Response: Do Clickers Improve Learning?

A number of studies have focused on how students and instructors feel about digital learning technologies. This research is focused on the substantive difference in learning outcomes between traditional classrooms and classrooms using clickers. A randomized block experimental design involving four sections of undergraduate Operations Management classes was used to determine if clicker systems increase student learning of both quantitative and conceptual material in Operations Management. Learning was measured using the difference between the scores on an entrance examination and the final examination. The findings of this research provide evidence that the use of immediate feedback using a technology like clickers can have a positive impact on student learning as measured by test scores.     

Learners and learning contexts: international perspectives on new alignments for the digital age

Educational technology research and development - Twelve papers representing 59 authors from 16 different nations are included in this special issue addressing the theme of ‘Learners and...     

The Civil Rights Commission Must Persist

Columnist George Will and others have questioned the continuing need for a federal civil rights commission, because civil rights protections have been on the books since 1964. The chairman of the Commission, Gerald Reynolds, here responds that practitioners of critical legal theory, advocates of the Akaka-Secession bill, some proponents of diversity, and others like them may make the continued existence of his commission a necessity.     

Creative Arts Personal Pedagogy vs Marketised Higher Education: A battle between values

The ongoing marketisation of higher education in England can be understood both conceptually – in terms of its ideological commitment to competition and accountability; and practically – in terms of the way that it has altered higher education structurally in a variety of ways. Methods of standardisation and quantification offer validation and reward to institutions through criteria aligned with marketised principles, leading to institutions shaping their operations to suit these forms of justification. Historically, many arts subjects have operated conceptually and organisationally outside the traditional higher education paradigm, and pedagogic approaches and values that are attributable to this subject area could clash with marketised understandings of education, which are becoming more prevalent and influential. This article presents analysis of reflections from creative arts educational practitioners working within higher education institutions in England on explorations of an ontology of the creative arts, as well as experiences of the marketisation process. A series of values relating to the concept of ‘the personal’, inherent to the creative arts are discussed and an exploration of how these principles clash with the priorities of the marketised educational economy are articulated. The values and principles that are inherent to educators and practitioners working in the creative arts are competing with ‘marketised’ motives imposed on them by the institutions in which they work.