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Chague-Goff C.,University of New South Wales | Chague-Goff C.,Australian Nuclear Science and Technology Organisation | Andrew A.,Environmental Isotopes Pty. Ltd | Szczucinski W.,ckiewicz University In Poznan | And 2 more authors.
Sedimentary Geology

The geochemical signature of the Tohoku-oki tsunami deposit and underlying soil was assessed two months, five months and seven months after the 11 March 2011 tsunami inundated the Sendai Plain. The extent of the recognisable sand deposit was traced up to 2.9km inland while a mud deposit was found up to 4.65km inland, representing 60% and nearly 95% of the maximum tsunami inundation, respectively. The limit of tsunami inundation was identified 4.85km from the shore using geochemical marine markers (S and Cl) two months after the tsunami, in the absence of any sedimentological evidence. Concentrations of other geochemical markers (K, Ca, Sr) indicative of the marine incursion and associated minerals were found to decrease landward. δ13C and δ15N and C/N ratios suggested a mixture of terrestrial and marine organic sources in the sediment, while δ34S of sulphate reflected the marine source of water soluble salts. The chemical composition of the 869AD Jogan tsunami sand deposit was characterised by high Sr and Rb concentrations and was comparable to that of the Tohoku-oki tsunami deposit, suggesting that the sources of sediment may be similar. Marked decreases in S and Cl with time indicated that rainfall resulted in the leaching of salts from the sandy sediments. However, both S and Cl markers as well as Sr were still well preserved in the muddy sediments and underlying soil beyond the limit of the recognisable sand deposit seven months after the tsunami. This suggests that geochemical indicators may well be useful in identifying the extent of historical and palaeotsunamis by determining the marine origin of fine grained sediments beyond the limit of recognisable sand deposition, in particular when marine microfossils are sparse or lacking as is the case on the Sendai Plain. This would allow researchers to redraw palaeotsunami inundation maps and re-assess the magnitude of events such as the Jogan tsunami and other palaeotsunamis, not only on the Sendai Plain but also elsewhere around the world. This has important implications for tsunami risk assessment, hazard mitigation and preparedness. © 2012 Elsevier B.V. Source

Depondt Ph.,University Pierre and Marie Curie | Levy J.-C.S.,CNRS Materials and Quantum Phenomena Laboratory | Mamica S.,ckiewicz University In Poznan
Journal of Physics Condensed Matter

Langevin simulations at finite temperature of two-dimensional magnetic nanodots were performed using the Landau-Lifshitz equation with exchange and dipolar interactions. In a wide range of temperatures, the dynamics of square samples with one central vortex was studied, focusing on the out-of-plane magnetic component at the vortex-core. This vortex-core undergoes polarization sign reversals in a thermally activated process. In the intervals between polarization flips, the out-of-plane spin components at the vortex-core show oscillations with identifiable frequencies connected with certain eigenfrequencies of the system associated with polarity active modes. The vortex-core positions were also monitored. © 2013 IOP Publishing Ltd. Source

Kozirog A.,University of Lodz | Brycki B.,ckiewicz University In Poznan
Acta Biochimica Polonica

Quaternary ammonium salts (QAS) belong to surfactant commonly used both, in the household and in different branches of industry, primarily in the process of cleaning and disinfection. They have several positive features inter alia effectively limiting the development of microorganisms on many surfaces. In the present work, two compounds were used as biocides: hexamethylene-1,6-bis-(N, N-dimethyl-N-dodecylammonium bromide) that belongs to the gemini surfactant (GS), and its single analogue - dodecyl(trimethyl)ammonium bromide (DTAB). Two fold dilution method was used to determine the minimum concentration of compounds (MIC) which inhibit the growth of bacteria: Staphylococcus aureus (ATCC 6538 and an environmental strain), Pseudomonas aeruginosa (ATCC 85327 and an environmental strain), and yeast Candida albicans (ATCC 11509 and an environmental strain). The viability of cells in liquid cultures with addition of these substances at 1/4 MIC, 1/2 MIC and MIC concentrations were also determined. The obtained results show that DTAB inhibits the growth of bacteria at the concentration of 0.126-1.010 μM/ml, and gemini surfactant is active at 0.036-0.029 μM/ml. Therefore, GS is active at more than 17-70-fold lower concentrations than its monomeric analogue. Strains isolated from natural environment are less sensitive upon testing biocides than the references strains. Both compounds at the MIC value reduced the number of cells of all strains. The use of too low concentration of biocides can limit the growth of microorganisms, but often only for a short period of time in case of special environmental strains. Later on, they can adapt to adverse environmental conditions and begin to evolve defence mechanisms. Source

Wojtera-Kwiczor J.,University of Osnabruck | Wojtera-Kwiczor J.,ckiewicz University In Poznan | Gross F.,University of Osnabruck | Leffers H.-M.,University of Osnabruck | And 3 more authors.
Frontiers in Plant Science

The cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPDH, EC, GapC) plays an important role in glycolysis by providing the cell with ATP and NADH. Interestingly, despite its glycolytic function in the cytosol, GAPDH was reported to possess additional non-glycolytic activities, correlating with its nuclear, or cytoskeletal localization in animal cells. In transiently transformed mesophyll protoplasts from Arabidopsis thaliana colocalization and interaction of the glycolytic enzymes with the mitochondria and with the actin cytoskeleton was visualized by confocal laser scanning microscopy (cLSM) using fluorescent protein fusions and by bimolecular fluorescence complementation, respectively. Yeast two-hybrid screens, dot-blot overlay assays, and co-sedimentation assays were used to identify potential protein-protein interactions between two cytosolic GAPDH isoforms (GapC1, At3g04120; GapC2, At1g13440) from A. thaliana with the neighboring glycolytic enzyme, fructose 1,6-bisphosphate aldolase (FBA6, At2g36460), the mitochondrial porin (VDAC3; At5g15090), and actin in vitro. From these experiments, a mitochondrial association is suggested for both glycolytic enzymes, GAPDH and aldolase, which appear to bind to the outer mitochondrial membrane, in a redox-dependent manner. In addition, both glycolytic enzymes were found to bind to F-actin in co-sedimentation assays, and lead to bundling of purified rabbit actin, as visualized by cLSM. Actin-binding and bundling occurred reversibly under oxidizing conditions. We speculate that such dynamic formation of microcompartments is part of a redox-dependent retrograde signal transduction network for adaptation upon oxidative stress. © 2013 Wojtera-Kwiczor, Groß, Leffers, Kang, Schneider and Scheibe. Source

Chague-Goff C.,University of New South Wales | Chague-Goff C.,Australian Nuclear Science and Technology Organisation | Niedzielski P.,ckiewicz University In Poznan | Wong H.K.Y.,Australian Nuclear Science and Technology Organisation | And 3 more authors.
Sedimentary Geology

Large areas of farmland in the Sendai Plain, Japan, were inundated by the 11 March 2011 Tohoku-oki tsunami and covered by a discontinuous 30-0.2cm thick sediment layer consisting of sand and/or mud and generally thinning and fining inland. Two months after the tsunami, numerous rice paddy fields and depressions remained ponded with brackish or saline water. A series of field surveys in May, August and October 2011 were carried out north of Sendai airport, in order to assess the environmental impact of the tsunami. While evaporation had resulted in elevated conductivity in ponded water in May (up to 68.2mScm-1), rainfall over the next five months led to dilution, although brackish water was still recorded in depressions and on paddy fields. Tsunami sediments, underlying soil and soil beyond the tsunami inundation limit were collected at 43 sites along and near a transect extending over 5km inland, and analysed for grain size, organic content, water leachable ions, acid leachable metals and exchangeable metalloids. Water leachable anion and cation concentrations were elevated in sandy and muddy tsunami deposits and soils particularly in areas, where seawater had stagnated for a longer period of time after the tsunami, with up to 10.5% Cl, 6.6% Na, 2.8% SO4, 440mgkg-1 Br measured in surface sediments (<0.5cm depth). Vertical variations were also recorded, with higher concentrations often measured in the surface samples. A similar trend could be observed for some of the metalloids (As) and metals (Zn, Cu and Ni), although in general, maximum concentrations of metals and metalloids were not much higher than in soils not inundated by the tsunami and were within background levels for uncontaminated Japanese soils.The impact of saltwater inundation was documented in the chemistry of soils underlying tsunami sediments, which were affected by salt contamination down to ~. 15. cm depth, and soils not covered by tsunami deposits. The latter implies that the extent of tsunami inundation may successfully be determined using geochemical markers in absence of any sedimentological evidence. Water leachable ions mostly decreased over time, however, they remained high enough to impact on rice farming, which was completely halted in 2011. Although further work is required to assess the longer term impact of tsunami inundation, flushing of salt with freshwater, as well as the possible removal of sandy/muddy sediments and underlying soil are recommended to allow crop production to resume. © 2012 Elsevier B.V. Source

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