There is little information in the conservation literature with respect to artists’ alkyd paints; thus, artists and conservators are somewhat at a loss about how to use and treat alkyds. Recently, analytical methods have been developed to identify the components in these polymers (oil modified polyesters), rates of cross-linking and mechanical properties. Presented in this paper are some of the characterization results of artists’ alkyd paints using THM (thermally assisted hydrolysis and methylation) gas chromatography– mass spectrometry (THM–GC/MS) and Fourier transform infrared spectroscopy–attenuated total reflectance (FTIR–ATR). Four brands of artists’ alkyd paints containing alkyd resin have been analysed; one containing a phthalic anhydride and pentaerythritol based alkyd resin, two containing isophthalic acid and pentaerythritol based alkyd resins, and the final one containing both phthalic anhydride and isophthalic acid and pentaerythritol based resins among the colours studied. 相似文献
The purpose of this paper is to introduce the ‘Do It Yourself’ (DIY) framework as a mode of critical qualitative scholarship. The authors argue that the production and distribution methods used by punks, zine-makers, graffitists, and skateboarders – among others – may support the social justice intentions of critical qualitative inquiry. The use the DIY framework to suggest activism itself is a collaborative process shaped by the frictions between activists and dominant systems, but mediated by the consumers of cultural production. Through examples and case studies, the authors demonstrate how DIY methods support patterns of collaboration that can lead to social change. The paper concludes with a proposal for DIY scholarship that suggests how critical qualitative researchers can amplify the utility of their methods to support social justice. 相似文献
The aims of the present study were: i) to examine the associations of total accelerometer-based sedentary time (ST) and specific-domain self-reported ST (i.e., screen-based, educational-based, social-based, and other-based ST) with adiposity and physical fitness in youth; and ii) to analyse the mediation effect of physical activity (PA) on associations.
This study was conducted with 415 children (9.1 ± 0.4 years) and 853 adolescents (13.6 ± 1.6 years) in Spain during 2011–2012. Total ST and PA were assessed by accelerometry. Leisure-time spent in twelve sedentary behaviours was self-reported. Adiposity and physical fitness was measured following the ALPHA battery for youth.
Total accelerometer-based ST was positively associated with global adiposity score in children, and negatively associated with global physical fitness score in children and adolescents; but relationships were not independent of PA. PA mediated all associations of accelerometer-based and self-reported ST with adiposity or physical fitness in children. Conversely, screen-, educational-, social-, and other-based ST were negatively related to physical fitness in adolescents, independently of PA.
These findings give an impetus to developing effective strategies for specifically promoting PA in children and for increasing PA while reducing ST in adolescents in order to produce improvements on adiposity and physical fitness. 相似文献
ABSTRACTDrawing on a pragmatist approach to pricing, this article discusses the impact of cost-effectiveness analysis (CEA) in the pricing strategies of pharmaceutical companies. Through an analysis of the human papillomavirus (HPV) vaccination, this article illustrates the strategic appropriation of evidence-based medicine (narratives and practices) that pharmaceutical companies have undertaken to enhance the value of their products. While governments are concentrated on the measurement of costs and efficiency (cost-effectiveness), companies attempt to find the threshold of effectiveness that supports their estimation of value. I have called such mode of calculation, price-effectiveness. Pharmaceutical companies engage in different ways with CEA in devising their own price strategies. First, CEA is used as an instrument to raise HPV vaccines as a matter of interest for health authorities. Second, companies produce models to maximise the effectiveness of their products. Third, the expense side of CEA has opened an opportunity to represent some conditions as diseases in order to increase the potential value of the vaccine, expressed in a higher price. Debates and practices of pricing offer a unique opportunity to trace how particular forms of quantification have become the common ground in the demonstration of value in healthcare and the adaptation of companies. 相似文献
Background: Children and adolescents can be distinguished by different typologies (clusters) of physical activity and sedentary behavior. How physical activity ... 相似文献
In the future systems of ambient intelligence will include decision support systems that will automate the process of discrimination
among people that seek entry into environments and to engage in search of the opportunities that are available there. This
article argues that these systems must be subject to active and continuous assessment and regulation because of the ways in
which they are likely to contribute to economic and social inequality. This regulatory constraint must involve limitations
on the collection and use of information about individuals and groups. The article explores a variety of rationales or justifications
for establishing these limits. It emphasizes the unintended consequences that flow from the use of these systems as the most
compelling rationale. 相似文献