17 research outputs found

    Analysis of fluoride in toothpastes on the Belgian market.

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    &lt;p&gt;We developed a method for the quantitative determination of sodium fluoride (NaF), sodium monofluorophosphate (SMFP) and amine fluoride (AmF) in toothpastes on the Belgian market. Samples were suspended in water and the determination was made using anion chromatography with conductivity detection after chemical suppression. The described ion chromatographic method is an easy and reliable isocratic high-performance liquid chromatography method for the determination of total soluble fluoride content in toothpastes. The analytical repeatability and reproducibility, the matrix effects and the method&#039;s decision limit of three different toothpastes containing NaF, SMFP and AmF at a concentration close to the permitted one of 0.15 g % total F are determined. All the samples analysed are in conformity with the Cosmetics Directive 76/768/EC; none exceeds the limit of 0.15 g %.&lt;/p&gt;</p

    Applied machine vision of plants: a review with implications for field deployment in automated farming operations

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    Automated visual assessment of plant condition, specifically foliage wilting, reflectance and growth parameters, using machine vision has potential use as input for real-time variable-rate irrigation and fertigation systems in precision agriculture. This paper reviews the research literature for both outdoor and indoor applications of machine vision of plants, which reveals that different environments necessitate varying levels of complexity in both apparatus and nature of plant measurement which can be achieved. Deployment of systems to the field environment in precision agriculture applications presents the challenge of overcoming image variation caused by the diurnal and seasonal variation of sunlight. From the literature reviewed, it is argued that augmenting a monocular RGB vision system with additional sensing techniques potentially reduces image analysis complexity while enhancing system robustness to environmental variables. Therefore, machine vision systems with a foundation in optical and lighting design may potentially expedite the transition from laboratory and research prototype to robust field tool

    Effects of dexamethasone on the profile of cytokine secretion in human whole blood cell cultures.

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    EXPERIMENTAL OBJECTIVES: The interaction between the endocrine and immune systems is a very intriguing area. Endogenous glucocorticoids, as end-effectors of the hypothalamo-pituitary-adrenal axis, inhibit the immune and inflammatory responses and are used as immunosuppressive drugs in many inflammatory, autoimmune and allergic diseases. The aims of this study were to investigate the effects of dexamethasone on the profile of cytokine secretion in whole blood cell cultures from healthy subjects and to analyse the gender-related sensitivity to dexamethasone on each cytokine secretion. RESULTS: There was a significant inhibition by dexamethasone (from 1 to 100 nM) on the secretion of monokines (IL-1beta, IL-6, IL-8 and TNF alpha) and lymphokines (IL-2, IL-4, IL-10 and IFN gamma), either after LPS or PHA stimulation (P < 0.01). Interleukin 4 and IL-10 were less inhibited than IFN gamma (P < 0.05 at 1 nM, P < 0.01 at 10 nM and P < 0.001 from 100 nM to 10 microM). No gender difference was observed in the rate of inhibition of the secretion of each cytokine. CONCLUSION: This study shows that the inhibition of cytokine secretion by dexamethasone is more marked on Th1-type cytokines than on Th2-type cytokines. These data support the idea that glucocorticoids may induce a shift from the Th1 to Th2 profile of cytokine secretion.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

    Weed detection in 3D images

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    Machine vision has been successfully used for mechanical destruction of weeds between rows of crops. Knowledge of the position of the rows where crops should be growing and the assumption that plants growing outside such positions are weeds may be used in such systems. However for many horticultural crops, the automatic removal of weeds from inside a row or bands of crops in which the weeds are mixed with plants in a random manner is not solved. The aim of this study was to verify that plant height is a discriminating parameter between crop and weed at early growth stages, as weeds and crops grow at different speeds. Plant height was determined by using an active stereoscopy technique, based on a time multiplexing coded structured light developed to take into account the specificities of the small scale scene, namely occlusion and thin objects, internal reflections and high dynamic range. The study was conducted on two carrot varieties sown at commercial density. Different weed species were present at the time of data acquisition. To accurately represent plant height taking into account the ground irregularities, a new parameter called ‘corrected plant height’ was computed. This parameter was the distance between plant pixels and the actual ground level under them obtained by fitting a surface and seen from a reconstructed point of view corresponding to a camera’s optical axis perpendicular to the ridge plane. The overall classification accuracy without correction was 66% whereas it reached 83% by using the corrected plant height
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