772 research outputs found

    Increased circulating insulin-like growth factor-1 in late-onset Alzheimer's disease

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    Background: Insulin-like growth factor (IGF)-1 has been implicated in the pathogenesis of Alzheimer's disease ( AD). Methods: We compared the level of circulating total and bioavailable IGF-1, by simultaneous measurements of IGF-1 and IGF binding protein ( IGFBP)-3, between 87 patients diagnosed with AD and 126 age and sex matched control subjects without cognitive impairment. Blood samples were collected and IGF-1 and IGFBP-3 measured by ELISA. Subjects were also genotyped for apolipoprotein E. Results: Total circulating IGF-1 levels were significantly raised in the AD group as compared to the control group (p = 0.022). There was no significant difference in the circulating level of IGFBP-3 between the two groups. When the IGF-1 levels were ratioed against IGFBP-3 levels as an indicator of unbound, bioavailable circulating IGF-1, there was a significant increase in the molar IGF-1:IGFBP-3 ratio in the AD subjects (0.181 +/- 0.006) as compared to the controls (0.156 +/- 0.004) (p < 0.001). Logistic regression analysis revealed that an increase in the IGF-1: IGFBP-3 molar ratio increased the risk of AD significantly. Conclusion: The results of increased total and free circulating IGF-1 support the hypothesis that in its early stages late-onset AD reflects a state of resistance to IGF-1

    Molecular dynamics simulation studies of the influence of imidazolium structure on the properties of imidazolium/azide ionic liquids

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    Journal ArticleAtomistic molecular dynamics simulations were performed on 1-butyl-3-methyl-imidazolium azide [bmim][N3], 1-butyl-2,3-dimethylimidazolium azide [bmmim][N3], and 1-butynyl-3-methylimidazolium azide [bumim][N3] ionic liquids. The many-body polarizable APPLE&P force field was augmented with parameters for the azide anion and the bumim cation. Good agreement between the experimentally determined and simulated crystal structure of [bumim][N3] as well as the liquid-state density and ionic conductivity of [bmmim][N3] were found. Methylation of bmim (yielding bmmim) resulted in dramatic changes in ion structuring in the liquid and slowing of ion motion. Conversely, replacing the butyl group of bmim with the smaller 2-butynyl group resulted in an increase of ion dynamics

    An Energy Use and Emissions Inventory of Cedarville University (2003-2013)

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    The rising cost of fossil fuels has been paralleled by an interest in maximizing efficiency and conservation at all levels (individual to corporate). Amidst this the burning of fossil fuels carries with it concerns regarding the contribution of the resulting emissions to climate change. This has generated interest in energy conservation and the use of renewable energy. In this time period Cedarville University has demonstrated a strong interest in managing its energy use (and associated greenhouse gas emissions) with emphasis on cost effectiveness. Thus, the objective of our study is to analyze Cedarville University’s energy use and carbon emissions from 2008 through the end of 2013. We will collect data on all sources of energy use and related emissions including electricity consumption, natural gas for heating, commuting, gasoline consumption, trash output, water use, and paper use. These data will be organized into the Campus Carbon Calculator to determine how much each factor contributes toward the campus’ carbon footprint. We will use the data to analyze the efficiency of the campus’ energy use by investigating energy use and emissions per student and per square foot of building space over the last decade. These data will serve as an update to the energy audit completed in 2008. Furthermore this will serve as a baseline to compare the lasting impact of the campus efficiency upgrades as well as the 2 megawatt solar array installed in March 2013

    Heavily loaded ferrite-polymer composites to produce high refractive index materials at centimetre wavelengths

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    A cold-pressing technique has been developed for fabricating composites composed of a polytetrafluoroethylene-polymer matrix and a wide range of volume-fractions of MnZn-ferrite filler (0%–80%). The electromagnetic properties at centimetre wavelengths of all prepared composites exhibited good reproducibility, with the most heavily loaded composites possessing simultaneously high permittivity (180 ± 10) and permeability (23±2). The natural logarithm of both the relative complex permittivity and permeability shows an approximately linear dependence with the volume fraction of ferrite. Thus, this simple method allows for the manufacture of bespoke materials required in the design and construction of devices based on the principles of transformation optics

    The College News, 1936-04-08, Vol. 22, No. 19

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    Bryn Mawr College student newspaper. Merged with The Haverford News in 1968 to form the Bi-college News (with various titles from 1968 on). Published weekly (except holidays) during the academic year

    Integrated methodologies of economics and socio-economics assessments in ocean renewable energy : private and public perspectives

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    This paper offers a holistic approach to the evaluation of an ocean renewable energy (ORE) technology type or specific project in order to provide a comprehensive assessment of both narrow economic and broader socio-economic performance. This assessment incorporates methods from three pillars areas: Economic - financial returns and efficient use of resources, Social - employment, social and community cohesion and identity, and Environmental - including the physical environment and pollution. These three pillars are then considered in the broader context of governance. In order to structure this evaluation, a novel parameter space model was created, defined by the three pillars and by the scale of the system under assessment. The scale of the system ranged from individual components of an ORE project; to projects comprising of a number of devices; through to a geographic regions in which multiple farms may be deployed. The parameter space consists of an inner circle representing the boundary of interest for a private investor, or a firm, developing an ORE project. The outer circle is characterised by assessment tools typically employed at the broader stakeholder level including economic, social, and environmental methods that can be employed at local, regional or national scale and which are typically employed to inform policy and decision making regarding ORE. Governance sets the stage within which management occurs. Wider impacts to the firm undertaking the project will take into account “externalities” of the project across the three fields. In this model, key methods identified are mapped onto this parameter space and the connectivity explored. The paper demonstrates that the three pillars are inter-connected and each must be considered in any meaningful assessment of ORE sustainability. An integrated assessment approach has the ability to address both the private and the public aspects of an ORE development,. This analysis provides insights on existing best practice, but also reveals the potential for disconnect between an ORE project’s commercial viability and its contribution to environmental and social goals

    Terahertz imaging through emissivity control

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    This is the final version. Available on open access from Optica Publishing Group via the DOI in this recordData availability: Data underlying the results presented in this paper are not publicly available at this time but may be obtained from the authors upon reasonable request.Electromagnetic radiation in the terahertz (THz) frequency band has unique potential for future communication and imaging applications.However, the adoption of THz technologies is hindered by the lack of cost-effective THz sources. Here we demonstrate a way to generate and control THz radiation, via spatio-temporal emissivity modulation. By patterning the optical photoexcitation of a surface-passivated silicon wafer, we locally control the free-electron density, and thereby pattern the wafer's emissivity in the THz part of the electromagnetic spectrum.We show how this unconventional source of controllable THz radiation enables a form of incoherent computational THz imaging.We use it to image various concealed objects, demonstrating that this scheme has the penetrating capability of other THz imaging approaches, without the requirement of femtosecond pulsed laser sources. Furthermore, the incoherent nature of thermal radiation also ensures the obtained images are free of interference artifacts. Our spatio-temporal emissivity control could enable a family of long-wavelength structured illumination, imaging, and spectroscopy systems.Engineering and Physical Sciences Research Council (EPSRC)European Research Council (ERC)Royal Academy of Engineering (RAE

    Evidence for Secretion of a Netrin-1-like Protein by Tetrahymena thermophila

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    Netrin-1 is a pleiotropic signaling molecule with targets in many mammalian cell types. Though first characterized as a chemotactic signal involved in neuronal guidance during development, netrin-1 has since been found to have a regulatory role in angiogenesis, and is also used as a biomarker in certain cancers. Tetrahymena thermophila are free-living protists that rely on chemotactic signals to find food, as well as to escape predators. Chemoattractants cause the cells to swim faster in the forward direction, while chemorepellents cause ciliary reversal, resulting in movement of the cell away from the noxious stimulus. We have previously found that netrin-1 is a chemorepellent in T. thermophila. More recently, we have detected netrin-1 by ELISA in both whole cell extract and secreted protein samples obtained from T. thermophila. In addition, we have immunolocalized netrin-1 staining to the cytosol of T. thermophila using an anti-netrin-1 antibody. We are currently running Western blots to determine the molecular weight of this protein and compare it to its vertebrate counterparts. Further experimentation is needed to determine the physiological role of this protein in T. thermophila
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