SVD-Based Universal Spatial Domain Image Steganalysis

This paper is concerned with the universal (blind) image steganalysis problem and introduces a novel method to detect especially spatial domain steganographic methods. The proposed steganalyzer models linear dependencies of image rows/columns in local neighborhoods using singular value decomposition transform and employs content independency provided by a Wiener filtering process. Experimental results show that the novel method has superior performance when compared with its counterparts in terms of spatial domain steganography. Experiments also demonstrate the reasonable ability of the method to detect discrete cosine transform-based steganography as well as the perturbation quantization method.

Bronzino’s allegory of ‘Venus and Cupid’: An exemplary image for contemporary sexual health promotion?

Recent sexual health promotion strategies have veered between a negative emphasis on the deleterious consequences of sexually transmitted infections, and a more positive, eroticized approach to safer sex. The differences in approach are starkly reflected in the images chosen to illustrate them. We note that there are problems with both approaches. The main purpose of this review is to demonstrate how this dichotomy was transcended by the sixteenth century Florentine Mannerist painter, Agnolo Bronzino, in his allegory on syphilis

Children making sense of science

Abstract This study explored the effects that the incorporation of nature of science (NoS) activities in the primary science classroom had on children’s perceptions and understanding of science. We compared children’s ideas in four classes by inviting them to talk, draw and write about what science meant to them: two of the classes were taught by ‘NoS’ teachers who had completed an elective nature of science (NoS) course in the final year of their Bachelor of Education (B.Ed) degree. The ‘non-NoS’ teachers who did not attend this course taught the other two classes. All four teachers had graduated from the same initial teacher education institution with similar teaching grades and all had carried out the same science methods course during their B.Ed programme. We found that children taught by the teachers who had been NoS-trained developed more elaborate notions of nature of science, as might be expected. More importantly, their reflections on science and their science lessons evidenced a more in-depth and sophisticated articulation of the scientific process in terms of scientists “trying their best” and “sometimes getting it wrong” as well as “getting different answers”. Unlike children from non-NoS classes, those who had engaged in and reflected on NoS activities talked about their own science lessons in the sense of ‘doing science’. These children also expressed more positive attitudes about their science lessons than those from non-NoS classes. We therefore suggest that there is added value in including NoS activities in the primary science curriculum in that they seem to help children make sense of science and the scientific process, which could lead to improved attitudes towards school science. We argue that as opposed to considering the relevance of school science only in terms of children’s experience, relevance should include relevance to the world of science, and NoS activities can help children to link school science to science itself.

Determination of absolute ion yields from a MALDI source through calibration of an image-charge detector

MALDI (matrix-assisted laser desorption/ionization) is one of the most important techniques used to produce large biomolecular ions in the gas phase. Surprisingly, the exact ionization mechanism is still not well understood and absolute values for the ion yields are scarce. This is in part due to the unknown efficiencies of typical detectors, especially for heavy biomolecular ions. As an alternative, charged particles can be non-destructively detected using an image-charge detector where the output voltage signal is proportional to the total charge within the device. In this paper, we report an absolute calibration which provides the voltage output per detected electronic charge in our experimental arrangement. A minimum of 3 x 10(3) ions were required to distinguish the signal above background noise in a single pass through the device, which could be further reduced using filtering techniques. The calibration results have been applied to raw MALDI spectra to measure absolute ion yields of both matrix and analyte ions.

Sense and sensibility: The role of business incubator client advisors in assisting high-technology entrepreneurs to make sense of investment readiness status

For high-technology entrepreneurs, attaining an appropriate level of investment to support new ventures is challenging as substantial investment is usually required prior to revenue generation. Consequently, entrepreneurs must present their firms as investment ready in the context of an uncertain market response and an absence of any trading history. Gaining tenancy within a business incubator can be advantageous to this process given that placement enhances entrepreneurial contact with potential investors whilst professional client advisors (CAs) use their expertise to assist in the development of a credible business plan. However, for the investment proposal to be successful, it must make sense to fund managers despite their lack of technological expertise and product knowledge. Thus, this article explores how incubator CAs and entrepreneurs act in concert to mould innovative ideas into plausible business plans that make sense to venture fund investors. To illustrate this process, we draw upon empirical evidence which suggests that CAs act as sense makers between venture fund managers (VFMs) and high-technology entrepreneurs, yet their role and influence appears undervalued. These findings have implications for entrepreneurial access to much needed funding and also for the identification of investment opportunities for VFMs. © 2011 Taylor & Francis.