52 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 ÎŒm × 5 ÎŒm 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

    Associations between maternal urinary iodine assessment, dietary iodine intakes and neurodevelopmental outcomes in the child: A Systematic Review

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    Abstract Objective Mild to moderate iodine deficiency during pregnancy has been associated with adverse neurodevelopmental outcomes in offspring. Few research studies to date combine assessment of urinary iodine (UIC and/or ICr), biomarkers that best reflect dietary intake, with reported dietary intake of iodine rich foods in their assessment of iodine deficiency. Thus, a systematic review was conducted to incorporate both these important measures. Design Using PRISMA guidelines, a comprehensive search was conducted in three electronic databases (EMBASEÂź, MedLineÂź and Web of ScienceÂź) from January 1970–March 2021. Quality assessment was undertaken using the Newcastle Ottawa Scale. Eligible studies included reported assessment of iodine status through urinary iodine (UIC and/or ICr) and/or dietary intake measures in pregnancy alongside neurodevelopmental outcomes measured in the children. Data extracted included study author, design, sample size, country, gestational age, child age at testing, cognitive tests, urinary iodine assessment (UIC in ÎŒg/L and/or ICr in ÎŒg/g), dietary iodine intake assessment and results of associations for the assessed cognitive outcomes. Results Twelve studies were included with nine reporting women as mild-moderately iodine deficient based on World Health Organization (WHO) cut-offs for urinary iodine measurements < 150 Όg/l, as the median UIC value in pregnant women. Only four of the nine studies reported a negative association with child cognitive outcomes based on deficient urinary iodine measurements. Five studies reported urinary iodine measurements and dietary intakes with four of these studies reporting a negative association of lower urinary iodine measurements and dietary iodine intakes with adverse offspring neurodevelopment. Milk was identified as the main dietary source of iodine in these studies. Conclusion The majority of studies classified pregnant women to be mild-moderately iodine deficient based on urinary iodine assessment (UIC and/or ICr) and/or dietary intakes, with subsequent offspring neurodevelopment implications identified. Although a considerable number of studies did not report an adverse association with neurodevelopmental outcomes, these findings are still supportive of ensuring adequate dietary iodine intakes and urinary iodine monitoring throughout pregnancy due to the important role iodine plays within foetal neurodevelopment. This review suggests that dietary intake data may indicate a stronger association with cognitive outcomes than urinary iodine measurements alone. The strength of this review distinguishes results based on cognitive outcome per urinary iodine assessment strategy (UIC and/or ICr) with dietary data. Future work is needed respecting the usefulness of urinary iodine assessment (UIC and/or ICr) as an indicator of deficiency whilst also taking account of dietary intakes

    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 TĂ©lescope HĂ©liographique pour l’Étude du MagnĂ©tisme et des InstabilitĂ©s 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

    Stabilization of a Modified Slotine-Li Adaptive Robot Controller by Robust Fixed Point Transformations

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    The \u201cAdaptive Slotine-Li Robot Controller (ASLRC)\u201d of the nineties of the past century was designed by a sophisticated process based on the use of Lyapunov\u2019s 2 nd method. In the possession of the exact analytical form of the system model it generally can achieve global asymptotic stability by learning the system\u2019s exact dynamic parameters. However, it is not robust to friction effects and unknown external disturbances. In contrast to that the adaptive controllers designed by the use of \u201cRobust Fixed Point Transformations (RFPT)\u201d are only locally stable, work on the mathematical basis of Banach\u2019s Fixed Point Theorem, cannot learn the system\u2019s analytical model parameters but they are very robust to modeling deficiencies (e.g. abandoned friction effects) and unknown external forces. In this paper it is shown that by evading the use of Lyapunov function in the adaptive control design an appropriate modification of the ASLRC can be elaborated that is able to properly learn the exact model parameters if external disturbances are missing. It can be combined with the RFPT-based controller that makes it robust to formal modeling inconsistencies and external forces, though in this case it cannot learn the appropriate system parameters. It is also shown that the symbiosis with the RFPT-based method does not disturb the parameter identification process if modeling inconsistencies and disturbances are absent

    Hybrid MS-BIEM for seismic site response phenomena: case study of Sofia

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    The study presents and solves the 2-D elastodynamic model for seismic in-plane wave propagation in laterally inhomogeneous geological profiles imbedded in a vertically inhomogeneous half-space in which an earthquake source is buried. To this end, an efficient hybrid modal summation- boundary integral equation method (MSM-BIEM) is developed and applied. The MSM is used as a tool for simulating wave propagation from the source position to the multilayered laterally inhomogeneous geological profile where the BIEM is applied. The proposed model and the hybrid tool are used to investigate the phenomena of site effects. In fact, such a methodology has the potential to investigate the combined effects of different physical phenomena like surface topography, lateral inhomogeneity and the existence of water saturation in soils on the estimation of site effects. The model and hybrid computational tool developed are applied to contribute to the seismic risk analysis of the Bulgarian capital Sofia
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