5,205 research outputs found

    Understanding vision: students’ use of light and optics resources

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    We present a qualitative study designed to examine how students construct an understanding of the human eye and vision from their knowledge of light and optics. As would be expected, vast differences are shown to exist between pre- and post-instruction students in terms of not only resource use, but also willingness to transfer their existing knowledge. However, we have found that appropriate scaffolding can facilitate resource activation and guide students to construct an understanding of vision and vision defects

    Energy planning for Indian nations within the WRAP: A field guide: Working paper series--05-14

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    This paper provides an overview of the process for developing a tribal energy plan. The process includes the following steps: developing a tribal energy vision, energy efficiency programs, renewable energy resource development, electrification programs and energy plan implementation. Working with the Hualapai Tribe in Arizona, the workshop curriculum was presented and led to instantaneous energy efficiency projects. Stemming from the tribal reports from the Western Regional Air Partnership (WRAP), the foremost recommendation for the 237 tribes within the WRAP was to create energy plans. Tribes should begin the process of energy planning due to the following issues: economic development (cost savings, revenue generation, job creation, and profit creation), increasing tribal sovereignty, energy independence, and cultural integrity

    Apparatus for investigating resonance with application to magnetic resonance imaging

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    Citation: Murphy, S., Jones, D. L., Gross, J., & Zollman, D. (2015). Apparatus for investigating resonance with application to magnetic resonance imaging. American Journal of Physics, 83(11), 942-947. doi:10.1119/1.4928177Resonance is typically studied in the context of either a pendulum or a mass on a spring. We have developed an apparatus that enables beginning students to investigate resonant behavior of changing magnetic fields, in addition to the properties of the magnetic field due to a wire and the superposition of magnetic fields. In this resonant system, a compass oscillates at a frequency determined by the compass's physical properties and an external magnetic field. While the analysis is mathematically similar to that of the pendulum, this apparatus has an advantage that the magnetic field is easily controlled, while it is difficult to control the strength of gravity. This apparatus has been incorporated into a teaching module on magnetic resonance imaging. (C) 2015 American Association of Physics Teachers

    Readily accessible sp3-rich cyclic hydrazine frameworks exploiting nitrogen fluxionality

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    Increased molecular complexity correlates with improved chances of success in the drug development process. Here, a strategy for the creation of sp3-rich, non-planar heterocyclic scaffolds suitable for drug discovery is described that obviates the need to generate multiple stereogenic centers with independent control. Asymmetric transfer hydrogenation using a tethered Ru-catalyst is used to efficiently produce a range of enantiopure cyclic hydrazine building blocks (up to 99% ee). Iterative C–N functionalization at the two nitrogen atoms of these compounds produces novel hydrazine and hydrazide based chemical libraries. Wide chemical diversification is possible through variation in the hydrazine structure, use of different functionalization chemistries and coupling partners, and controlled engagement of each nitrogen of the hydrazine in turn. Principal Moment of Inertia (PMI) analysis of this small hydrazine library reveals excellent shape diversity and three-dimensionality. NMR and crystallographic studies confirm these frameworks prefer to orient their substituents in three-dimensional space under the control of a single stereogenic center through exploitation of the fluxional behavior of the two nitrogen atoms

    Spatial sampling heterogeneity limits the detectability of deep time latitudinal biodiversity gradients

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    The latitudinal biodiversity gradient (LBG), in which species richness decreases from tropical to polar regions, is a pervasive pattern of the modern biosphere. Although the distribution of fossil occurrences suggests this pattern has varied through deep time, the recognition of palaeobiogeographic patterns is hampered by geological and anthropogenic biases. In particular, spatial sampling heterogeneity has the capacity to impact upon the reconstruction of deep time LBGs. Here we use a simulation framework to test the detectability of three different types of LBG (flat, unimodal and bimodal) over the last 300 Myr. We show that heterogeneity in spatial sampling significantly impacts upon the detectability of genuine LBGs, with known biodiversity patterns regularly obscured after applying the spatial sampling window of fossil collections. Sampling-standardization aids the reconstruction of relative biodiversity gradients, but cannot account for artefactual absences introduced by geological and anthropogenic biases. Therefore, we argue that some previous studies might have failed to recover the ‘true’ LBG type owing to incomplete and heterogeneous sampling, particularly between 200 and 20 Ma. Furthermore, these issues also have the potential to bias global estimates of past biodiversity, as well as inhibit the recognition of extinction and radiation events

    Validation of text-mining and content analysis techniques using data collected from veterinary practice management software systems in the UK

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    Electronic patient records from practice management software systems have been used extensively in medicine for the investigation of clinical problems leading to the creation of decision support frameworks. To date, technologies that have been utilised for this purpose such as text mining and content analysis have not been employed significantly in veterinary medicine.The aim of this research was to pilot the use of content analysis and text-mining software for the synthesis and analysis of information extracted from veterinary electronic patient records. The purpose of the work was to be able to validate this approach for future employment across a number of practices for the purposes of practice based research. The approach utilised content analysis (Prosuite) and text mining (WordStat) software to aggregate the extracted text. Text mining tools such as Keyword in Context (KWIC) and Keyword Retrieval (KR) were employed to identify specific occurrences of data across the records. Two different datasets were interrogated, a bespoke test dataset that had been set up specifically for the purpose of the research, and a functioning veterinary clinic dataset that had been extracted from one veterinary practice.Across both datasets, the KWIC analysis was found to have a high level of accuracy with the search resulting in a sensitivity of between 85.3–100%, a specificity of between 99.1–99.7%, a positive predictive value between 93.5–95.8% and a negative predictive value between 97.7–100%. The KR search, based on machine learning, was utilised for the clinic-based dataset and was found to perform slightly better than the KWIC analysis.This study is the first to demonstrate the application of content analysis and text mining software for validation purposes across a number of different datasets for the purpose of search and recall of specific information across electronic patient records. This has not been demonstrated previously for small animal veterinary epidemiological research for the purposes of large scale analysis for practice-based research. Extension of this work to investigate more complex diseases across larger populations is required to fully explore the use of this approach in veterinary practice

    Use of clinical vignette questionnaires to investigate the variation in management of keratoconjunctivitis sicca and acute glaucoma in dogs

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    There is little peer-reviewed research assessing therapeutic effectiveness in canine eye disease. Current treatments used in first opinion and ophthalmology referral practices are also somewhat poorly documented. The aim of this study was to investigate the current management of canine keratoconjunctivitis sicca (KCS) and acute primary angle-closure glaucoma (PACG) by veterinary surgeons. Questionnaires using clinical vignettes were administered to a cross section of general practitioners (‘GPs’) and veterinarians engaged in or training for postgraduate ophthalmology practice (’PGs’). Similar treatment recommendations for KCS (topical cyclosporine, lubricant, antibiotic) were given by both groups of veterinarians with the single exception of increased topical antibiotic use by GPs. Treatment of acute glaucoma diverged between groups: PGs were much more likely to recommend topical prostaglandin analogues (PGAs) and a wider array of both topical and systemic treatments were recommended by both groups. Systemic ocular hypotensive agents were suggested infrequently. Our results suggest that treatments may vary substantially in ocular conditions, particularly in conditions for which neither guidelines nor high quality evidence exists. This study highlights the need for novel strategies to address evidence gaps in veterinary medicine, as well as for better evaluation and dissemination of current treatment experience

    A Strategic Approach to Public Health Workforce Development and Capacity Building

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    In February 2010, CDC’s National Center for HIV/AIDS, Viral Hepatitis, Sexually Transmitted Disease (STD), and Tuberculosis (TB) Prevention (NCHHSTP) formally institutionalized workforce development and capacity building (WDCB) as one of six overarching goals in its 2010–2015 Strategic Plan. Annually, workforce team members finalize an action plan that lays the foundation for programs to be implemented for NCHHSTP’s workforce that year. This paper describes selected WDCB programs implemented by NCHHSTP during the last 4 years in the three strategic goal areas: (1) attracting, recruiting, and retaining a diverse and sustainable workforce; (2) providing staff with development opportunities to ensure the effective and innovative delivery of NCHHSTP programs; and (3) continuously recognizing performance and achievements of staff and creating an atmosphere that promotes a healthy work–life balance. Programs have included but are not limited to an Ambassador Program for new hires, career development training for all staff, leadership and coaching for mid-level managers, and a Laboratory Workforce Development Initiative for laboratory scientists. Additionally, the paper discusses three overarching areas—employee communication, evaluation and continuous review to guide program development, and the implementation of key organizational and leadership structures to ensure accountability and continuity of programs. Since 2010, many lessons have been learned regarding strategic approaches to scaling up organization-wide public health workforce development and capacity building. Perhaps the most important is the value of ensuring the high-level strategic prioritization of this issue, demonstrating to staff and partners the importance of this imperative in achieving NCHHSTP’s mission

    Exploring tissue engineering

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    In this Creative Inquiry, we have two main projects. Our first project aims to improve the cell culture process by eliminating the need for trypsin, an enzyme that dissociates cells from the surfaces they grow on, but also compromises cell membrane integrity and can kill cells over time. This will be done by growing cells on solar panels. Induced current via light exposure will repel the proteins from the surface so that the cells can be collected. The second project aims to determine the most viable and reproducible method of culturing cells in 3D geometry. Initial studies were done on fibroblast cells and further studies will focus on mimicking tumors. Various culturing environments, cell lines, and culturing surfaces (such as non-adhering surfaces) will be done to alter the geometries, size, and composition of the 3D geometries. The first project would be useful for pharmaceutical companies who culture large volumes of cells and for researchers who wish to study specific cell membrane proteins while the second project has applications in cancer research

    Effect of Bone Marrow-Derived Mesenchymal Stem Cells on Endotoxin-Induced Oxidation of Plasma Cysteine and Glutathione in Mice

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    Bone marrow-derived mesenchymal stem cells (BMDMSC) are emerging as a therapeutic modality in various inflammatory disease states, including acute lung injury (ALI). A hallmark of inflammation, and a consistent observation in patients with ALI, is a perturbation in the systemic redox environment. However, little is known about the effects of BMDMSC on the systemic redox status. The objective of the present study was to determine whether exogenously infused BMDMSC protect against endotoxin-induced oxidation of plasma cysteine (Cys) and glutathione (GSH) redox states. To determine the effect on the redox state if BMDMSC, mice received endotoxin intraperitoneally (1 mg/kg), followed by intravenous infusion of either 5 × 105 BMDMSC or an equal volume of saline solution. Control mice received intraperitoneal endotoxin followed by 5 × 105 lung fibroblasts given intravenously. Cys, cystine (CySS), GSH, and glutathione disulfide (GSSG) concentrations were determined by HPLC. Results showed sequential preservation of plasma Cys and GSH levels in response to BMDMSC infusion. The data show that BMDMSC infusion leads to a more reducing Cys and GSH redox state. The findings are the first to demonstrate that BMDMSC have antioxidant effects in vivo, and add to our understanding of the systemic effects of BMDMSC in lung injury
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