Advancing image quantification methods and tools for analysis of nanoparticle electrokinetics

Image processing methods and techniques for high-throughput quantification of dielectrophoretic (DEP) collections onto planar castellated electrode arrays are developed and evaluated. Fluorescence-based dielectrophoretic spectroscopy is an important tool for laboratory investigations of AC electrokinetic properties of nanoparticles. This paper details new, first principle, theoretical and experimental developments of geometric feature recognition techniques that enable quantification of positive dielectrophoretic (pDEP) nanoparticle collections onto castellated arrays. As an alternative to the geometric-based method, novel statistical methods that do not require any information about array features, are also developed using the quantile and standard deviation functions. Data from pDEP collection and release experiments using 200 nm diameter latex nanospheres demonstrates that pDEP quantification using the statistic-based methods yields quantitatively similar results to the geometric-based method. The development of geometric- and statistic-based quantification methods enables high-throughput, supervisor-free image processing tools critical for dielectrophoretic spectroscopy and automated DEP technology development

Real-time dielectrophoretic signaling and image quantification methods for evaluating electrokinetic properties of nanoparticles

Real-time image signaling and quantification methods are described that allow easy-to-use, fast extraction of the electrical properties of nanoparticles. Positive dielectrophoretic (pDEP) collection rate analysis enables the dielectric properties of very small samples of nanoparticles to be accurately quantified. Advancing earlier work involving dual-cycle pulsed pDEP [1] collection experiments, we report the development of a statistical image quantification method that significantly advances the evaluation of nanoparticle dielectric properties. Compared with traditional methods that require information about the geometry of the electrode array to be entered for semiautomated quantification [2], the new statistical approach described does not require a priori knowledge of device geometry. The efficacy of the statistical method is experimentally demonstrated using 200 nm diameter latex nanospheres, suspended in low conductivity medium, that are attracted by pDEP onto planar castellated electrode arrays with 5-micron-sized features. The method is shown to yield estimates for the nanoparticle conductivity and surface conductance, inline image mS/m and inline image nS, that concur closely with those obtained using traditional geometric methods previously reported [1]. Consequently, the statistical method is accurate, fast, robust, supervisor-free, and useful for determining nanoparticle electrokinetic parameters

Characterising the Fermentation Capabilities of Gut Microbial Populations from Different Breeds of Cattle and Sheep Grazing Heathland

Previous studies have demonstrated differences in the diet composition of sheep and cattle when grazing heather moorland, and such differences may in turn lead to differences in rumen fermentation characteristics and associated adaptation to diet. To investigate this further an in vitro gas production experiment was conducted using inocula from different breeds of cattle and sheep grazing heathland

The Effect of Dry Matter Content and Inoculation with Lactic Acid Bacteria on the Residual Water Soluble Carbohydrate Content of Silages Prepared from a High Sugar Grass Cultivar

The introduction of new perennial ryegrass cultivars bred for high water soluble carbohydrate (WSC) content has created opportunities for improving the quality of grass silage, by not only providing adequate WSC for a good fermentation, but also sufficient to leave a higher residual level of WSC in the mature silage. High WSC silages have the potential to provide readily available energy during the early stages of rumen fermentation to balance energy and nitrogen supply and optimise rumen microbial growth. (Merry et al. 2002). The aim was to examine the effect of wilting and silage inoculants on the residual WSC content of grass silage

Ways to Reduce Peak Electrical Demand in South Louisiana

This study analyses alternatives for coping with the peak electrical demand of hot summer afternoons. Economic and Political aspects, as well as technical feasibility, are included. It is concluded that South Louisiana may indeed be able to trim peak demand to 5% below what is anticipated by 1980 , thus making one of the coal fired stations scheduled then unnecessary. However, the contingencies (Natural Gas Shortage, Another Oil Embargo) would make a coal-fired station very desirable

Rigor and Ethics in the World of Big-team Qualitative Data: Experiences From Research in International Development

In the large international projects where many qualitative researchers work, generating qualitative Big Data, data sharing represents the status quo. This is rarely acknowledged, even though the ethical implications are considerable and span both process and product. I argue that big-team qualitative researchers can strengthen claims to rigor in analysis (the product) by drawing on a growing body of knowledge about how to do credible secondary analysis. Since this necessitates a full account of how the research and the analysis are done (the process), I consider the structural disincentives for providing these. Debates around credibility and rigor are not new to qualitative research in international development, but they intensify when new actors such as program evaluators and quantitative researchers use qualitative methods on a large scale. In this context, I look at the utility of guidelines used by these actors to ensure the quality of qualitative research. I ask whether these offer pragmatic suggestions to improve its quality, recognizing the common and hierarchized separation between the generation and interpretation of data, or conversely, whether they set impossible standards and fail to recognize the differences between and respective strengths of qualitative and quantitative research

Exploring rationales for branding a university: Should we be seeking to measure branding in UK universities?

Although branding is now widespread among UK universities, the application of branding principles in the higher education sector is comparatively recent and may be controversial for internal audiences who question its suitability and efficiency. This paper seeks to investigate how and whether the effectiveness of branding activity in the higher education sector should be evaluated and measured, through exploratory interviews with those who often drive it; UK University marketing professionals. Conclusions suggest that university branding is inherently complex and therefore application of commercial approaches may be over simplistic. Whilst marketing professionals discuss challenges they do not necessarily have a consistent view of the objectives of branding activity although all were able to clearly articulate branding objectives for their university, including both qualitative and, to some extent, quantitative metrics. Some measures of the real value of branding activity are therefore suggested but a key debate is perhaps whether the objectives and role of branding in higher education needs to be clarified, and a more consistent view of appropriate metrics reached? Various challenges in implementing branding approaches are also highlighted

Confluence up to Garbage

No abstract available