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- Abdul-Ahad, Amir Stefan, et al.
(författare)
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Robust distance-based watermarking for digital image
- 2008
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Ingår i: Proceedings of the 2008 International Conference on Security and Management, SAM 2008. - 160132085X - 9781601320858 ; , s. 404-409
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Konferensbidrag (refereegranskat)abstract
- In this paper, an algorithm is developed to invisibly watermark a cover object (color image) using watermark object (iconic image). The algorithm is based on the distances among the addresses of values of the cover object. These distances use to make the embedding. The order of manipulating these distances are specified by the values of the watermark data which is dealt with serially. The algorithm serves and achieves self encryption key. Each watermark object has its unique pattern of distances at different possible lengths of distance bits. This enhances the complexity of sequential embedding. The algorithm is tested using direct and single level and double level of Two-Dimensional Discrete Wavelet Transform (2D DWT) embeddings. Two important issues are addressed. Firstly is to achieve a high Peak Signal to Noise Ratio (PSNR). The ratio was found to increase with an increasing of distance bits. Secondly is that the watermarked object retains the same properties of cover object. The algorithm shows resisting and withstanding against the most important attacks. Some of these include the lossy compression, blurring, resize and some types of Noise.
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- Ahad, Abdul, et al.
(författare)
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Actin is bundled in activation-tagged tobacco mutants that tolerate aluminum
- 2007
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Ingår i: Planta. - New York : Springer. - 0032-0935 .- 1432-2048. ; 225:2, s. 451-468
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Tidskriftsartikel (refereegranskat)abstract
- A panel of aluminum-tolerant (AlRes) mutants was isolated by protoplast-based T-DNA activation tagging in the tobacco cultivar SR1. The mutants fell into two phenotypic classes: a minority of the mutants were fertile and developed similarly to the wild type (type I), the majority was male-sterile and grew as semi-dwarfs (type II). These traits, along with the aluminum tolerance, were inherited in a monogenic dominant manner. Both types of mutants were characterized by excessive bundling of actin microfilaments and by a strongly increased abundance of actin, a phenotype that could be partially phenocopied in the wild type by treatment with aluminum chloride. The actin bundles could be dissociated into finer strands by addition of exogenous auxin in both types of mutants. However, actin microfilaments and leaf expansion were sensitive to blockers of actin assembly in the wild type and in the mutants of type I, whereas they were more tolerant in the mutants of type II. The mutants of type II displayed a hypertrophic development of vasculature, manifest in form of supernumerary leaf veins and extended xylem layers in stems and petioles. Whereas mutants of type I were characterized by a normal, but aluminum-tolerant polar auxin-transport, auxin-transport was strongly promoted in the mutants of type II. The phenotype of these mutants is discussed in terms of reduced endocytosis leading, concomitantly with aluminum tolerance, to changes in polar auxin transport.
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- Keech, Olivier, et al.
(författare)
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Leaf senescence is accompanied by an early disruption of the microtubule network in Arabidopsis.
- 2010
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Ingår i: Plant Physiology. - : American Society of Plant Biologists. - 0032-0889 .- 1532-2548. ; 154:4, s. 1710-1720
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Tidskriftsartikel (refereegranskat)abstract
- The dynamic assembly and disassembly of microtubules (MTs) is essential for cell function. Although leaf senescence is a well-documented process, the role of the MT cytoskeleton during senescence in plants remains unknown. Here, we show that both natural leaf senescence and senescence of individually darkened Arabidopsis (Arabidopsis thaliana) leaves are accompanied by early degradation of the MT network in epidermis and mesophyll cells, whereas guard cells, which do not senesce, retain their MT network. Similarly, entirely darkened plants, which do not senesce, retain their MT network. While genes encoding the tubulin subunits and the bundling/stabilizing MT-associated proteins (MAPs) MAP65 and MAP70-1 were repressed in both natural senescence and dark-induced senescence, we found strong induction of the gene encoding the MT-destabilizing protein MAP18. However, induction of MAP18 gene expression was also observed in leaves from entirely darkened plants, showing that its expression is not sufficient to induce MT disassembly and is more likely to be part of a Ca(2+)-dependent signaling mechanism. Similarly, genes encoding the MT-severing protein katanin p60 and two of the four putative regulatory katanin p80s were repressed in the dark, but their expression did not correlate with degradation of the MT network during leaf senescence. Taken together, these results highlight the earliness of the degradation of the cortical MT array during leaf senescence and lead us to propose a model in which suppression of tubulin and MAP genes together with induction of MAP18 play key roles in MT disassembly during senescence.
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| 9. |
- Keech, Olivier, et al.
(författare)
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The different fate of mitochondria and chloroplasts during dark-induced senescence in Arabidopsis leaves
- 2007
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Ingår i: Plant, Cell and Environment. - Oxford : Blackwell Scientific Publications Ltd. - 0140-7791 .- 1365-3040. ; 30:12, s. 1523-1534
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Tidskriftsartikel (refereegranskat)abstract
- Senescence is an active process allowing the reallocation of valuable nutrients from the senescing organ towards storage and/or growing tissues. Using Arabidopsis thaliana leaves from both whole darkened plants (DPs) and individually darkened leaves (IDLs), we investigated the fate of mitochondria and chloroplasts during dark-induced leaf senescence. Combining in vivo visualization of fates of the two organelles by three-dimensional reconstructions of abaxial parts of leaves with functional measurements of photosynthesis and respiration, we showed that the two experimental systems displayed major differences during 6 d of dark treatment. In whole DPs, organelles were largely retained in both epidermal and mesophyll cells. However, while the photosynthetic capacity was maintained, the capacity of mitochondrial respiration decreased. In contrast, IDLs showed a rapid decline in photosynthetic capacity while maintaining a high capacity for mitochondrial respiration throughout the treatment. In addition, we noticed an unequal degradation of organelles in the different cell types of the senescing leaf. From these data, we suggest that metabolism in leaves of the whole DPs enters a ‘stand-by mode’ to preserve the photosynthetic machinery for as long as possible. However, in IDLs, mitochondria actively provide energy and carbon skeletons for the degradation of cell constituents, facilitating the retrieval of nutrients. Finally, the heterogeneity of the degradation processes involved during senescence is discussed with regard to the fate of mitochondria and chloroplasts in the different cell types.
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| 10. |
- Khan, Abdul Ahad, et al.
(författare)
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Algal biochar : A natural solution for the removal of Congo red dye from textile wastewater
- 2024
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Ingår i: Journal of the Taiwan Institute of Chemical Engineers / Elsevier. - : Elsevier. - 1876-1070 .- 1876-1089.
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Tidskriftsartikel (refereegranskat)abstract
- The present study was aimed at synthesizing algae-derived biochar to examine its effectiveness and adsorption capacity to remove Congo red dye. The independent variables such as dye concentration, adsorbent dose, and adsorption time were optimized by using a central composite design (CCD). An adsorption experiment was conducted to evaluate equilibrium using a detailed experimental design and characterized through XRD, TGA, SEM, EDX, and FTIR analysis. This paper also focuses on evaluating non-linear adsorption isotherm and kinetics to describe the adsorption mechanism along with applying an Artificial neural network to validate the removal efficiency. The maximum Congo red removal efficiency (96.14 %) and maximum adsorption capacity of algal biochar (186.94 mg/g) were achieved with the optimized parameters of 1 mg/L of dye concentration, 0.1 g of adsorbent dose, and 240 min of contact time. Adsorption behavior was well described by Langmuir isotherm and Pseudo-nth order. A multilayer perceptron (MLP) MLP 2–5–1 structure best validates the response. Overall, the study sheds light that Algal-derived biochar is a potential material for the elimination of Congo red dye and contributes to achieving sustainable development goals.
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