Increasing Awareness for the Indigenous in the 21st century: The creation of an Ojibwe Digital Archive

Benjamin P. Fletcher, College \u2709, English Increasing Awareness for the Indigenous in the 21st Century This study is part of a larger project entitled “Ben Franklin and the Lenape Indians,” underway at the Smithsonian Library of Congress maps section, whose purpose is to locate colonial maps of Pennsylvania that depict Lenape villages and place names. Historically, the Lenape are one of the most important tribes of the Eastern US, yet neither the Commonwealth of Pennsylvania nor the federal government recognizes them. Through the use of digital technology—videos of the Lenape’s current Chief Bob Redhawk Ruth, tribal archival records and oral history, as well as historical documents and maps—I hope to clearly identify the Lenape as an integral part of Pennsylvania’s cultural history

Actuatable Membranes based on Polypyrrole-Coated Vertically Aligned Nanostructures

Nanoporous membranes are an enabling technology in a wide variety of applications because of their ability to efficiently and selectively separate molecules. A great deal of effort is concentrated on developing methods of externally controlling membrane selectivity and on integrating the membranes within multi-scale systems. In this dissertation, synthetic nanoporous membranes that fit the described needs are constructed from vertically aligned nanostructures. Vertically aligned carbon nanofibers and anisotropically etched silicon posts are aligned perpendicular to the substrate and act as obstacles to material flow parallel to the surface. The distances between the outer edges of the nanostructures define the pores of the membranes. Transport through the membranes is controlled by physically selecting species as they pass between the vertically aligned nanostructures. Membrane properties such as permeability and porosity are specified by defining the spatial locations of the membrane components. Subsequent physical and chemical modification of the nanostructures enables further tuning of pore sizes and opens up new methods to controllably modulate the permeability of the membranes. In this dissertation, permeability is externally controlled by electrochemical actuation of the conductive polymer, polypyrrole. Vertically aligned membrane components are coated with the actuatable polymer. Upon electrochemical reduction, the polypyrrole coatings swell in volume, increasing the diameters of the membrane components and decreasing the pore sizes of the membranes. Modulating the physical size of the membrane pores enables size selective transport of species and gating of the nanoscale pores

Efficient 3D medical image segmentation

3D Medical imaging techniques have become extremely important tools in patient diagnosis. However, they produce large amounts of data that is difficult to interpret, and can currently only be analysed by highly trained people. Datasets are large – the female Visible Human dataset is around 40 Gb in size. Processing any dataset of this size will obviously be computationally demanding. Currently segmentation of images is a predominantly manual process. Tools that are available allow segmentation to be done on a slice-by-slice basis, often using a flood-fill or region growing approach based on colour or texture space. This report outlines research into an automated texture based segmentation technique. The research compared the effectiveness of using simple and energy efficient DCT (Discrete Cosine Transform) and Haar transforms (in both 2D and 3D forms) as a description of texture at each location within an image. This description was initially used as a vector in feature space, allowing segmentation to be carried out using a Gaussian Mixture Model and some post processing techniques. The transforms were then extended to make them independent of variations in intensity, a common issue in medical imaging. However, although now robust to intensity variations, the results were not of sufficient quality to be useful in a real application. To improve the quality of results, a model based approach based on an AAM (Active Appearance Model) was considered. A traditional AAM uses an intensity based appearance model, which while less computationally demanding than a more complex texture based appearance model, can give poor results when subjected to intensity variations. When complex texture descriptions are used to create the appearance model results are much improved, but this is at the expense of run time, which can make the techniques less practical. A novel combination of mDCT (modified DCT, which is intensity invariant) and an AAM was implemented and tested. When presented with 3D volumes which had been subjected to intensity variations this was seen to generate much better results than a traditional AAM, while maintaining a practical run time. Using this approach the time taken to carry out segmentations was less than 10 minutes (when run in Matlab on a typical datacentre based Linux machine). This showed the process to be practical in terms of quality of results, run time and energy efficiency

Numerical simulation of colloidal dispersion filtration: description of critical flux and comparison with experimental results

During filtration via membrane processes, colloids accumulate at the porous surface leading to fouling phenomena. In this study, a rigorous simulation of momentum and mass transfer using CFD modelling has been developed to describe such an accumulation during cross flow filtration. These simulations integrate detailed modeling of physicochemical properties specific to colloidal dispersions (because of the surface interactions (repulsive and attractive) occurring between the colloids particles). These interactions are accounted for via the experimental variation of the colloidal osmotic pressure with volume fraction (associated with a variation in the diffusion coefficient) which are fitted by a relationship integrated into the CFD code. It contains a description of the colloidal phase transition leading to the formation of a condensed phase (deposit or gel layer) from the accumulated dispersed phase (concentration polarization). It is then possible to determine the critical flux which separates filtration conditions below which mass accumulation is reversible (in the dispersed phase) and above which it is irreversible (in the condensed phase). The computed value of critical flux is compared with that determined experimentally for a dispersion of latex particles

Making Connections:John Darwin and his Histories of Empire

John Darwin and his Histories of Empir

Patient preferences for management of high blood pressure in the UK:A discrete choice experiment

Background: With a variety of potentially effective hypertension management options, it is important to determine how patients value different models of care, and the relative importance of factors in their decision-making process. Aim: To explore patient preferences for the management of hypertension in the UK. Design and setting: Online survey of patients who have hypertension in the UK including an unlabelled discrete choice experiment (DCE). Method: A DCE was developed to assess patient preferences for the management of hypertension based on four attributes: model of care, frequency of blood pressure (BP) measurement, reduction in 5-year cardiovascular risk, and costs to the NHS. A mixed logit model was used to estimate preferences, willingness-to-pay was modelled, and a scenario analysis was conducted to evaluate the impact of changes in attribute levels on the uptake of different models of care. Results: One hundred and sixty-seven participants completed the DCE (aged 61.4 years, 45.0% female, 82.0% >5 years since diagnosis). All four attributes were significant in choice (P<0.05). Reduction in 5-year cardiovascular risk was the main driver of patient preference as evidenced in the scenario and willingness-to-pay analyses. GP management was significantly preferred over self-management. Patients preferred scenarios with more frequent BP measurement, and lower costs to the NHS. Conclusion: Participants had similar preferences for GP management, pharmacist management, and telehealth, but a negative preference for self-management. When introducing new models of care for hypertension to patients, discussion of the potential benefits in terms of risk reduction should be prioritised to maximise uptake

Combination therapy with ciprofloxacin and pentamidine against Multidrug-Resistant Pseudomonas aeruginosa : assessment of in vitro and in vivo efficacy and the role of Resistance-Nodulation-Division (RND) efflux pumps

Funding: This research was funded by the University of St Andrews.The aim of this work was to (i) evaluate the efficacy of a combination treatment of pentamidine with ciprofloxacin against Galleria mellonella larvae infected with an MDR strain of P. aeruginosa and (ii) determine if pentamidine acts as an efflux-pump inhibitor. Resistant clinical isolates, mutant strains overexpressing one of three RND efflux pumps (MexAB-OprM, MexCD-OprJ, and MexEF-OprN), and a strain with the same three pumps deleted were used. MIC assays confirmed that the clinical isolates and the mutants overexpressing efflux pumps were resistant to ciprofloxacin and pentamidine. The deletion of the three efflux pumps induced sensitivity to both compounds. Exposure to pentamidine and ciprofloxacin in combination resulted in the synergistic inhibition of all resistant strains in vitro, but no synergy was observed versus the efflux-pump deletion strain. The treatment of infected G. mellonella larvae with the combination of pentamidine and ciprofloxacin resulted in enhanced efficacy compared with the monotherapies and significantly reduced the number of proliferating bacteria. Our measurement of efflux activity from cells revealed that pentamidine had a specific inhibitory effect on the MexCD-OprJ and MexEF-OprN efflux pumps. However, the efflux activity and membrane permeability assays revealed that pentamidine also disrupted the membrane of all cells. In conclusion, pentamidine does possess some efflux-pump inhibitory activity, in addition to a more general disruptive effect on membrane integrity that accounts for its ability to potentiate ciprofloxacin activity. Notably, the enhanced efficacy of combination therapy with pentamidine and ciprofloxacin versus MDR P. aeruginosa strains in vivo merits further investigation into its potential to treat infections via this pathogen in patients.Publisher PDFPeer reviewe

Stable carbon isotope analysis of Cedrus atlantica pollen as an indicator of moisture availability

Stable carbon isotope analysis of pollen provides potential for reconstruction of past moisture availability in the environment on longer time-scales compared to isotope analysis of plant tissue. Here we show that the carbon isotopic compositions (δ13C) of pollen, sporopollenin, leaf and stem tissues of Cedrus atlantica are strongly related. Untreated pollen δ13C has a significant linear relationship with sporopollenin δ13C (r2 = 0.97, p < 0.0001) which is relatively depleted in 13C by an average 1.5‰. Carbon isotope discrimination (Δ13C) by sporopollenin (derived from pollen δ13C values) is related to mean annual (r2 = 0.54, p < 0.001) and summer precipitation (r2 = 0.63, p < 0.0001). A 100 mm increase in mean annual precipitation results in sporopollenin Δ13C increasing by 0.52‰, or by 1.4‰ per 100 mm summer precipitation. There is a stronger relationship between sporopollenin Δ13C and long-term annual scPDSI (r2 = 0.86, p < 0.0001) and summer scPDSI (r2 = 0.86, p < 0.001) aridity indexes, with reduced Δ13C as aridity increases. These relationships suggest that stable carbon isotope analysis of C. atlantica fossil pollen could be used as a quantitative proxy for the reconstruction of summer moisture availability in Northwest Africa

Koalas use a novel vocal organ to produce unusually low-pitched mating calls

SummaryDuring the breeding season, male koalas produce ‘bellow’ vocalisations that are characterised by a continuous series of inhalation and exhalation sections, and an extremely low fundamental frequency (the main acoustic correlate of perceived pitch) [1]. Remarkably, the fundamental frequency (F0) of bellow inhalation sections averages 27.1 Hz (range: 9.8–61.5 Hz [1]), which is 20 times lower than would be expected for an animal weighing 8 kg [2] and more typical of an animal the size of an elephant (Supplemental figure S1A). Here, we demonstrate that koalas use a novel vocal organ to produce their unusually low-pitched mating calls