67 research outputs found

    Differential attraction and repulsion of Staphylococcus aureus and Pseudomonas aeruginosa on molecularly smooth titanium films

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    Magnetron sputtering techniques were used to prepare molecularly smooth titanium thin films possessing an average roughness between 0.18 nm and 0.52 nm over 5 μm × 5 μm AFM scanning areas. Films with an average roughness of 0.52 nm or lower were found to restrict the extent of P. aeruginosa cell attachment, with less than 0.5% of all available cells being retained on the surface. The attachment of S. aureus cells was also limited on films with an average surface roughness of 0.52 nm, however they exhibited a remarkable propensity for attachment on the nano-smoother 0.18 nm average surface roughness films, with the attachment density being almost twice as great as that observed on the nano-rougher film. The difference in attachment behaviour can be attributed to the difference in morphology of the rod-shaped P. aeruginosa compared to the spherical S. aureus cells

    Modelling Temperature Variation of Mushroom Growing Hall Using Artificial Neural Networks

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    The recent developments of computer and electronic systems have made the use of intelligent systems for the automation of agricultural industries. In this study, the temperature variation of the mushroom growing room was modeled by multi-layered perceptron and radial basis function networks based on independent parameters including ambient temperature, water temperature, fresh air and circulation air dampers, and water tap. According to the obtained results from the networks, the best network for MLP was in the second repetition with 12 neurons in the hidden layer and in 20 neurons in the hidden layer for radial basis function network. The obtained results from comparative parameters for two networks showed the highest correlation coefficient (0.966), the lowest root mean square error (RMSE) (0.787) and the lowest mean absolute error (MAE) (0.02746) for radial basis function. Therefore, the neural network with radial basis function was selected as a predictor of the behavior of the system for the temperature of mushroom growing halls controlling system

    The European Solar Telescope

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    The European Solar Telescope (EST) is a project aimed at studying the magnetic connectivity of the solar atmosphere, from the deep photosphere to the upper chromosphere. Its design combines the knowledge and expertise gathered by the European solar physics community during the construction and operation of state-of-the-art solar telescopes operating in visible and near-infrared wavelengths: the Swedish 1m Solar Telescope, the German Vacuum Tower Telescope and GREGOR, the French Télescope Héliographique pour l’Étude du Magnétisme et des Instabilités Solaires, and the Dutch Open Telescope. With its 4.2 m primary mirror and an open configuration, EST will become the most powerful European ground-based facility to study the Sun in the coming decades in the visible and near-infrared bands. EST uses the most innovative technological advances: the first adaptive secondary mirror ever used in a solar telescope, a complex multi-conjugate adaptive optics with deformable mirrors that form part of the optical design in a natural way, a polarimetrically compensated telescope design that eliminates the complex temporal variation and wavelength dependence of the telescope Mueller matrix, and an instrument suite containing several (etalon-based) tunable imaging spectropolarimeters and several integral field unit spectropolarimeters. This publication summarises some fundamental science questions that can be addressed with the telescope, together with a complete description of its major subsystems

    Development of the leaf blades of Acer platanoides in industrially contaminated environment

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    Leaf blades of Norway maple (Acer platanoides L.), growing in heavily polluted industrial area have been studied for anatomical changes developed under the influence of the industrial contamination (with SO2, NxOx, Pb, As). The aim of the examination was to reveal the dynamics in the development of leaf blades and to trace the impact of the contaminated air on the leaf structure of Norway maple. The conducted study registered acceleration of the vegetative growth of the leaf blades that is manifested through approximately two weeks earlier appearance of leaves on the tree, faster linear growth and strengthened the xeromorphic traits in the leaf structure of the tree plants from the contaminated region. The observed changes are regarded as adaptation of the plant to the polluted environment, i.e. as tolerance

    Comparative studies of the leaf morphology and structure of white ash Fraxinus americana L. and London plane tree Platanus acerifolia Willd growing in polluted area

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    The leaf blades of white ash Fraxinus americana L. and London plane tree Platanus acerifolia Willd. growing in heavy polluted industrial areas were studied for morphological and anatomical changes developed under the influence of industrial contamination. The aim of the investigation was to determine and compare the influences of air polluted with SO2, NxOx, Pb, As, Zn, Cu etc. on the morphology and the structure of the leaves of these deciduous trees. Both species are tolerant to environmental changes but with different environmental characteristics and tolerances and they are widely used for planting. Under polluted conditions, the trees strengthened the anatomic xeromorphic characteristics of their leaf structures, which gave them the opportunity to mitigate the stressful conditions of the environment. The observed responses are regarded as adaptive and compensative to the adverse effects of air pollution

    Leaf blade structure and the tolerance of Acer negundo L. (box elder) to the polluted environment

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    Polluted air is a stress factor that contributes to the decline of urban trees. Air pollution may cause short-term (acute) damage, which is immediately visible and long-term (chronic) damage, which can lead to gradual tree decline. Long-term damage may predispose trees to other disorders. The impact of technogenic factors on the leaf’s anatomical structure of Acer negundo L. (Box elder) was studied. The thickness of the upper cuticle is increased when compared to those from an ecologically pure area. A change in the rate of mesophyll tissue is due to the enlargement of the palisade parenchyma. The thickness of lower epidermal cells is decreased. All changes of the leaf blade structure are significant and are in direction of increasing the xerophyte characteristics of the leaves. Box elder is native to much of temperate North America. This is a tree of lowlands and wet hardwood forests. As such, we can assume that the registered changes are adaptive responses of the tree to the contaminated environment and that the tree can be considered to be relatively tolerant

    Growth and development of the leaf blades of Acer tataricum in industrially contaminated environment

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    During one vegetative season, the growth and the development of the leaf blades of Tatarian maple (Acer tataricum L.) from heavily polluted area has been studied. The region under investigation was contaminated mainly with SO2, NxOx, Pb, Zn, and Cu etc. The aim of the study was to compare the growth and the development of the leaf blades of Acer tataricum L. (Tatarian maple) from polluted field with those from non-polluted. Base on this to assess its tolerance to polluted conditions of the atmosphere, as well as to look for adaptive responses. The conducted study registered shorter time of the vegetative growth of the leaf blades in the commencement stages of the vegetative development. The leaves from polluted site had emergence approximately two weeks earlier compared with these from the control area. Faster linear growth of the leaf surfaces in the commencement stages of the development had been noted for the trees from polluted field. The spongy mesophyll had been reduced, as well as the common thickness of the leaf blades of the tree plants from the contaminated region. The observed changes are regarded as adaptation of the plant to the polluted environment, i.e. as tolerance

    Comment on "Infants' Perseverative Search Errors Are Induced by Pragmatic Misinterpretation"

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    Topál et al. (Reports, 26 September 2008, p. 1831) proposed that infants' perseverative search errors can be explained by ostensive cues from the experimenter. We use the dynamic field theory to test the proposal that infants encode locations more weakly when social cues are present. Quantitative simulations show that this account explains infants' performance without recourse to the theory of natural pedagogy
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