How content analysis may complement and extend the insights of discourse analysis: an example of research on constructions of abortion in South African newspapers 1978–2005

Although discourse analysis is a well-established qualitative research methodology, little attention has been paid to how discourse analysis may be enhanced through careful supplementation with the quantification allowed in content analysis. In this article, we report on a research study that involved the use of both Foucauldian discourse analysis (FDA) and directed content analysis based on social constructionist theory and our qualitative research findings. The research focused on the discourses deployed, and the ways in which women were discursively positioned, in relation to abortion in 300 newspaper articles, published in 25 national and regional South African newspapers over 28 years, from 1978 to 2005. While the FDA was able to illuminate the constitutive network of power relations constructing women as subjects of a particular kind, questions emerged that were beyond the scope of the FDA. These questions concerned understanding the relative weightings of various discourses and tracing historical changes in the deployment of these discourses. In this article, we show how the decision to combine FDA and content analysis affected our sampling methodology. Using specific examples, we illustrate the contribution of the FDA to the study. Then, we indicate how subject positioning formed the link between the FDA and the content analysis. Drawing on the same examples, we demonstrate how the content analysis supplemented the FDA through tracking changes over time and providing empirical evidence of the extent to which subject positionings were deployed

Assessing the potential for sea-based macroalgae cultivation and its application for nutrient removal in the Baltic Sea

Marine eutrophication is a pervasive and growing threat to global sustainability. Macroalgal cultivation is a promising circular economy solution to achieve nutrient reduction and food security. However, the location of production hotspots is not well known. In this paper the production potential of macroalgae of high commercial value was predicted across the Baltic Sea region. In addition, the nutrient limitation within and adjacent to macroalgal farms was investigated to suggest optimal site-specific configuration of farms. The production potential of Saccharina latissima was largely driven by salinity and the highest production yields are expected in the westernmost Baltic Sea areas where salinity is >23. The direct and interactive effects of light availability, temperature, salinity and nutrient concentrations regulated the predicted changes in the production of Ulva intestinalis and Fucus vesiculosus. The western and southern Baltic Sea exhibited the highest farming potential for these species, with promising areas also in the eastern Baltic Sea. Macroalgal farming did not induce significant nutrient limitation. The expected spatial propagation of nutrient limitation caused by macroalgal farming was less than 100–250 m. Higher propagation distances were found in areas of low nutrient and low water exchange (e.g. offshore areas in the Baltic Proper) and smaller distances in areas of high nutrient and high water exchange (e.g. western Baltic Sea and Gulf of Riga). The generated maps provide the most sought-after input to support blue growth initiatives that foster the sustainable development of macroalgal cultivation and reduction of in situ nutrient loads in the Baltic Sea.</p

Recording of Cell Action Potentials with AlGaN/GaN Field-Effect Transistor Arrays

An AlGaN/GaN electrolyte gate field-effect transistor array for the detection of electrical cell signals has been realized. The low-frequency noise power spectral density of these devices exhibits a 1/f characteristic with a dimensionless Hooge parameter of 5 X 10(-3). The equivalent gate-input noise under operation conditions has a peak-to-peak amplitude of 15 muV, one order of magnitude smaller than for common silicon-based devices used for extracellular recordings. Extracellular action potentials from a confluent layer of rat heart muscle cells cultivated directly on the nonmetallized gate surface were recorded with a signal amplitude of 75 muV and a signal-to-noise ratio of 5:1. (C) 2005 American Institute of Physics

Surfactant-mediated growth of indium on GaAs(001)

The influence of antimony as surfactant on the growth mode of indium on GaAs(001) has been investigated for deposition at various temperatures. Clean surfaces of (2 × 4) reconstruction were prepared in UHV by thermal desorption of a protective arsenic cap deposited on top of homoepitaxially grown MBE layers. Before In deposition, 2 ML Sb were pre-deposited on top of the clean GaAs surface of part of the samples. The In growth mode was then monitored by AES and compared with that occurring during In growth on GaAs without an Sb interlayer. After removal of the samples from UHV, SEM investigations show regularly shaped, flat In islands oriented along the 〈110〉 substrate directions. In comparison, In islands grown without an Sb interlayer also show a preferential orientation along the 〈110〉 substrate directions, but differ in shape and size. Low-temperature In deposition (120 K) leads to the formation of a continuous In layer, which tears during warm up to room temperature. An exchange between surfactant material and indium during growth is found for both low- and room-temperature In deposition. X-ray diffraction measurements show a strong influence of the Sb surfactant on the crystallinity of the In film