850 research outputs found

    Understanding the Impact of Fluid Viscosity on the Growth and Conjugation of Antimicrobial Resistant Donors and Recipients Pairs

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    To combat the spread of antimicrobial resistance (AMR), it is vital to link the behavior of donor and recipient bacteria in dynamic environments to horizontal gene transfer (HGT) potential- specifically, conjugation the primary means of spread of AMR genes. However, HGT is poorly understood under dynamic conditions, such as those in the gut of humans and animals. Most experiments are done under static conditions at viscosities similar to water, but these methods do not accurately represent the higher gut viscosities or movement. Hence, a next step to increase understanding of conjugation is with experiments using generic donor and recipient pairs at different viscosities. Accordingly, it is necessary to establish the relationship between viscosity and bacterial growth in these experiments, for which our hypothesis is that the rate of bacterial growth in fluids with higher viscosities will be lower due to water displacement. To test this hypothesis, experiments were designed to measure the number of donors, recipients and transconjugant bacteria using optical density. Varying concentrations of the thickeners agar and xanthan gum will be used to achieve different viscosity levels in the media. Media of thicknesses closer to that of bodily fluids, which are more alike to pancake syrup or batter, will be evaluated. Concentrations will be tracked at half hour intervals as a means to obtain data and to formulate a growth curve model. Some preliminary results indicate that our hypothesis has a good probability of being correct. Linear growth curve models were applied to the data for comparison purposes

    Growth of thin films of molybdenum and tungsten oxides by combustion CVD using aqueous precursor solutions

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    Using combustion chemical vapour deposition, layers of molybdenum and tungsten oxides have been deposited on glass and silicon at low temperatures. Inexpensive ammonium salts of molybdate and metatungstate ions were used as precursors and were delivered to the coating flame as an aqueous solution using a nebuliser. The resulting films were analysed by scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), Rutherford backscattering (RBS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). These indicate that the films are continuous, moderately smooth and consist of amorphous, disordered molybdenum and tungsten trioxides

    A survey of distribution patterns in the Montana alpine flora

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    Enhanced Bragg reflections from size-matched heterostructure photonic crystal thin films prepared by the Langmuir-Blodgett method

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    The Langmuir-Blodgett method was used to engineer photonic crystal thin films of an AB architecture. Structures were studied by transmittance and reflectance spectroscopies. For an AB structure in which the silica particle diameter B is twice that of A, reflectance features associated with the first order Bragg peak for the ``A'' domain are only observed when the structure is probed from the A side of the structure. Furthermore, this feature is enhanced in intensity compared to that for a structure consisting solely of A particles. These findings are attributed to a matching of first and second order Bragg processes

    Photonic crystal thin films of GaAs prepared by atomic layer deposition

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    Photonic crystal thin films were fabricated via the self-assembly of a lattice of silica spheres on silicon (100) substrates. Progressive infilling of the air spaces within the structure with GaAs was achieved using trimethylgallium and arsine under atomic-layer-deposition conditions. Samples with the highest levels of GaAs infill were subsequently inverted using selective etching. Reflectance spectra are interpreted via the Bragg expression and calculated photonic band structure diagrams. For GaAs infilled and inverted samples, the relative positions of the first and second order Bragg reflections are strongly influenced by the wavelength dependent refractive index

    Highly bioactive silver and silver/titania composite films grown by chemical vapour deposition

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    This paper describes how photocatalytically active films of TiO2, grown by thermal CVD, may be functionally and structurally modified by deposition of nano-structured silver via a novel flame assisted CVD process. The resulting composite films are shown to be highly durable, highly photocatalytically active and are also shown to possess strong antibacterial behaviour. The deposition control, arising from the described approach, offers the potential to control the film nanostructure, which is proposed to be crucial in determining the photo and bio-activity of the combined film structure, and the transparency of the composite films. Furthermore, we show that the resultant films also exhibit “self-regeneration” capability, in that they both kill bacteria present on the film surface and then photo-degrade the residues. Such a dual action significantly reducing the problems of surface deactivation due to build up of contamination. These properties are especially significant when combined with the well-known durability of CVD deposited thin films, offering new opportunities for enhanced application in areas where bioactive surface functionality is sought

    Sight loss, dementia and meaningful activity: A scoping study

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    The prevalence of health conditions causing or contributing to sight loss increases with age (Girdler et al, 2008). Yet, despite this, little research has focused on a population that has both sight loss and dementia, tending instead to focus on each condition in isolation.  Meaningful activity’ has been linked to quality of care and the health and wellbeing of older people (NICE 2013) and better outcomes for individuals with dementia (Wenborn et al. 2008). Regular engagement in meaningful activity has been shown to reduce severe behavioural symptoms of dementia, reduce reliance upon medicated solutions (Menne et al. 2012), slow functional decline associated with dementia and help to address the challenges of social isolation and ‘problematic passivity’, characterised by a decrease in gross motor movement accompanied by apathy and a lack of interaction with the environment (Conti et al. 2008). Loss of opportunities for, or access to, meaningful activities has been linked with depressive symptoms and affective distress in people with Age-related Macular Degeneration (AMD) (Rovner and Casten 2002). The present scoping study was commissioned to explore issues in relation to meaningful activities for people with both dementia and sight loss living in both community and residential settings. The present scoping study was commissioned to explore issues in relation to meaningful activities for people with both dementia and sight loss living in both community and residential settings.  The primary aims of the project were:  • To determine the extent of the evidence base relating to meaningful activity for people with sight loss and dementia, and to summarise what is known;  • To collect data on the availability and use of guidance, training and other relevant resources in this area; and • To provide insights to inform the potential development of new or improved guidelines in this area.  The aims of the research have been addressed through a combination of literature review (including online lateral searches), interviews with expert informants, and survey questionnaire on the provision of meaningful activity distributed to relevant stakeholder groups

    Writing Rock Stars: An After-School Community Partnership in Childhood Literacy

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    This study explains the development, implementation, and preliminary findings of an after-school pilot writing program that drew upon a peer collaborative model and a community literacy perspective. Preliminary findings suggest important benefits of this partnership for young children, parents, and the surrounding community

    Growth and formation of inverse GaP and InP opals

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    Opals consist of an ordered array of SiO2 spheres. This leads to a modulation of the refractive index and hence photonic stop bands behaviour over the visible/IR range of the electro-magnetic spectrum. The exact position of the stop bands depends on the size of the silica spheres. However, the refractive index contrast between the SiO2 spheres and air spaces is not great enough to open up a full photonic band gap (PBG), only the pseudogap. To increase the contrast the air spaces are filled with a material of high refractive index such as InP or GaP. To further increase the contrast the SiO2 is removed leaving a III-V framework as the inverse opal structure. By use of MOCVD we have been able to infill opals with InP and GaP to such a level that has supported the inversion of the composite forming a structure of air holes within a III-V lattice. XRD and Raman confirmed the quality of the III-V infill, while the extent of the infill was studied by SEM and reflectance measurements
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