Ageing of brazilwood dye in wool – a chromatographic and spectrometric study

Brazilwood was used in this work to dye wool mordanted with different amounts of copper(II) sulfate, alum and iron(II) sulfate. Two different dyeing methods were used: premordanting (MD) and simultaneous mordanting (M+D) procedures. In order to evaluate the influence of the mordant ion in the brazilein chromophore photodegradation, samples were subjected to artificial light ageing. Color measurements were made and, for the first time, LC-DAD-ESI-MS was used for chromophore analysis of the dyed fibers before and after light exposure. Mordant ion quantification was done after fiber acid digestion, by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and flame atomic absorption spectroscopy (FAAS). Mordant metal ion, mordant bath concentration and dyeing procedure were found to have strong influence in the wool fiber hues. Color variation was more pronounced in the alum dyed samples. Overall, mordant quantification showed that the amount of metal ions found in the fibers is very small when compared to the original concentrations of the dyeing bath, being Cu the ion with greater affinity for the wool fibers. MD dyeing procedure yielded fibers with larger amounts of mordant metal ions and higher chromophore peak areas. Higher amounts of brazilein were extracted from wool mordanted with copper(II) sulfate. Finally, chromatographic analysis of the brazilwood dyed samples before and after light exposure resulted in the detection of Type C compound as an outcome of the photodegradation process.     

An integrated approach to develop professional and technical skills for informatics engineering students

Many of the current approaches used in teaching and learning in engineering education are not the most appropriate to prepare students for the challenges they will face in their professional careers. The active involvement of students in their learning process facilitates the development of the technical and professional competencies they need as professionals. This article describes the organisation and impact of a mini-conference and project work – the creation of a software product and its introduction in the market – aimed at the development of professional competencies in general and writing skills in particular. The course was evaluated by assessing the students’ perception of the development of a number of professional competencies through a questionnaire completed by 125 students from two consecutive year groups. The results indicate that the project work and the mini-conference had a positive impact on students’ perceptions of the development of professional competencies.     

Students’ self-grading,professor’s grading and negotiated final grading at three university programmes: analysis of reliability and grade difference ranges and tendencies

This study was undertaken at three teacher education programmes and was designed to determine the following within each programme: (1) the reliability correlations among students’ self‐grade (SSG), the grade granted by the professor (PG) and the negotiated final grade (NFG); (2) the range and frequency of grade differences between SSG and PG; and (3) the tendency of the negotiation on NFG as compared to SSG (i.e. NFG > SSG or NFG < SSG), when SSG was not equal to PG. The samples were made up of three professors and their corresponding student groups (students, n = 100, 34 and 53, respectively), each in a different teacher education programme. The results show that there was a high reliability correlation among SSG, PG and NFG in all three programmes. Furthermore, in these programmes, the grade differences were never higher than 1.5 on a scale of 0 to 10 points; in fact, agreement between DDG and PG was reached 96%, 35.29% and 43.39% of the time), and, when disagreement emerged, it was mainly within a minimum range of 0.1 to 0.5 points. As for the tendency of NFG versus SSG in each programme, slightly higher percentages were obtained for NFG > SSG in Programmes B and C, whereas the opposite (NFG < SSG) was true in Programme A; overall, however, it could be said that both tendencies balanced each other out, being the total percentages in each programme 0%, 41% and 30% for NFG > SSG; and 4%, 23% and 26%, for NFG < SSG, respectively.     

On the role of novelty for search result diversification

Re-ranking the search results in order to promote novel ones has traditionally been regarded as an intuitive diversification strategy. In this paper, we challenge this common intuition and thoroughly investigate the actual role of novelty for search result diversification, based upon the framework provided by the diversity task of the TREC 2009 and 2010 Web tracks. Our results show that existing diversification approaches based solely on novelty cannot consistently improve over a standard, non-diversified baseline ranking. Moreover, when deployed as an additional component by the current state-of-the-art diversification approaches, our results show that novelty does not bring significant improvements, while adding considerable efficiency overheads. Finally, through a comprehensive analysis with simulated rankings of various quality, we demonstrate that, although inherently limited by the performance of the initial ranking, novelty plays a role at breaking the tie between similarly diverse results.     

Sanguine Paint: Production,Characterization, and Adhesion to the Glass Substrate

ABSTRACT

For centuries, the only painting materials used in stained-glass production were grisaille and yellow (silver) stain. At the end of the fifteenth century, stained-glass painters began to use a new material, sanguine. This paint is mainly produced with iron oxide particles, usually haematite, and allowed to obtain a colour that can vary from yellowish to brownish-red due to the nature and particle size of the iron oxide. A translucent sanguine was mostly applied as flesh and hair colour, with an opaque sanguine used for drapery, architectural motifs, and heraldry. The main goal of this study is to investigate the relationship between historic sources on the preparation and use of sanguine from the fifteenth to the nineteenth centuries and the evolution evidenced in the recipes regarding the production method. Representative recipes from several centuries (sixteenth to nineteenth centuries) were selected and reproduced for this study. These reconstructions were thoroughly characterized using X-ray powder diffraction, optical microscopy (OM), and fibre optic reflectance spectroscopy (FORS). The OM and FORS data were correlated with historic sanguine paints applied on historic stained-glass. The similarities and differences between historic and reconstructed paints are presented. The study of reconstructed sanguine’s adhesion to glass using cross-cut testing was also performed, revealing that the adhesion is strongly influenced, not only by the binder, but also by the composition and morphology of the sanguine paint.     

The Profile of a Modern Filipino Librarian: An Examination of Perceived Competencies

ABSTRACT

This research created a profile of a modern LIS professional by discussing the competencies and skills essential in successfully conducting one's duties. Through a series of focus group discussions and interviews, the researcher identified essential competencies modern LIS professionals should possess. Aside from traditional skills such as cataloging and classification; indexing and abstracting; and library management, non-traditional competencies such as communication skills, advocacy skills, teaching skills, and technological skills were revealed to be vital competencies. These were identified and further supported by discussions of actual library work experiences. In the end, a profile was created it was concluded that a modern LIS professional should be pro-active; an effective communicator; well-informed; adaptable; and should advocate causes relevant to the practice of librarianship.     

How to Understand the Gene in the Twenty-First Century?

It is widely acknowledged in the literature on philosophy of biology and, more recently, among biologists themselves that the gene concept is currently in crisis. This crisis concerns the so-called “classical molecular concept”, according to which a gene is a DNA segment encoding one functional product, which can be either a RNA molecule or a polypeptide. In this paper, we first describe three categories of anomalies that challenge this way of understanding genes. Then, we discuss proposals for revising the gene concept so as to accommodate the increasingly known complexity of genomic architecture and dynamics. Our intention is to provide an informative overview of recent proposals concerning how we should conceive of genes, which are probably not very familiar to many science educators and teachers, but can bring relevant contributions to genetics teaching, in particular, to a more critical treatment of genes and their role in living systems.     

Analysis of the Methods and Research Topics in a Sample of the Brazilian Distance Education Publications, 1992 to 2007

Abstract

The objective of this study was to identify the methodological approaches employed in a sample of Brazilian distance education scientific literature and compare with similar publications in the United States. Brazilian sample articles (N = 983) published in several journals and meetings were compared with a sample of articles published in The American Journal of Distance Education (AJDE) from 1987 to 2006. A categorization system based on Gall, Gall, and Borg (2006 Gall, J. P., Gall, M. D. and Borg, W. R. 2007. Educational research: An introduction, Boston: Pearson.  [Google Scholar]) and Lee, Driscoll, and Nelson (2007) Lee, Y. and Driscoll, M. P. 2007. “Trends in research: A content analysis of major journals”. In Handbook of distance education, 2nd, Edited by: Moore, M. G. 31–41. Mahwah, NJ: Erlbaum.  [Google Scholar] was used. The methodological approach employed in the Brazilian sample was predominantly qualitative, and this feature remained largely unchanged over the past seven years. The predominant research method continues to be exploratory, followed by case studies. Of note, the most frequent research topic in AJDE articles was evaluation, contrasting with the predominant topic of management in Brazilian publications.     

Quantity of Group Child Care,Behavior Problems,and Prosocial Behaviors: A Study with Portuguese Preschoolers

Research Findings: Data from a national sample of Portuguese preschool centers were used to examine the relationship between age of start and number of hours in child care and levels of externalizing and prosocial behaviors with peers. Participants were both parents and teachers of 543 children (mean age = 4.5 years, 50.6% girls). Children started child care between 3 and 64 months and were attending child care 1–9 hr per day. The child care centers’ classrooms had adult–child ratios between 5 and 8.7 and group sizes between 15 and 26 children. Externalizing and prosocial behavior with peers was assessed with the Social Competence and Behavior Evaluation Scale–Short Form completed by the 3 adult informants. Control variables included family sociodemographics and education level, maternal parenting style assessed with the Parenting Styles and Dimensions Questionnaire, and maternal stress assessed with the Parenting Experiences questionnaire. Practice or Policy: Both the number of hours per week in child care and an earlier start of center-based child care had modest but significant associations with dimensional scores from teachers’ reports of externalizing behavior but not with mothers’ or fathers’ reports, suggesting that externalizing behavior with peers could be regarded as context specific to peer relationships in group child care. There was no evidence that the quantity of exposure to child care per se could be a substantial risk factor for severe levels of externalizing behavior. Prosocial behavior with peers was not significantly associated with the number of hours in child care or with the age of entry into group child care.