1,881 research outputs found

    Adoption, Maintenance and Diffusion of Stormwater Best Management Practices: Rain Barrels

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    Urbanization increases the volume of stormwater runoff from homes, businesses and other paved areas of the urbanized landscape. Unable to infiltrate into the ground, stormwater is directed to facilities that can easily become overloaded and cause a variety of water quality issues. This study aims to assess urban homeowners’ motivations to adopt and maintain rain barrels, a stormwater best management practice (BMP), and evaluate how this BMP diffuses throughout a community. This research took place in the Great Bend of the Wabash River (Lafayette-West Lafayette, Indiana) and Salt Creek (Valparaiso, Indiana) watersheds and featured a mail survey of 571 residents, site performance evaluations of 130 rain barrels, a “windshield” assessment of 242 rain barrels, and 31 in-person interviews. Our results show that 88% of homeowners in the Great Bend of the Wabash River watershed have maintained their rain barrels after two years and 65% of homeowners in Salt Creek watershed after 5 years. One of the biggest issues homeowners had with maintaining their rain barrels were issues with water pressure. We also found that 94% of rain barrel owners maintain a flower or vegetable garden and their primary motivation for adopting a rain barrel was to reduce water use for their yard or house. Outreach may need to focus more on the importance of maintaining the rain barrels as well as emphasizing the connection between rain barrels and personal gardening

    Hydrodynamic attraction of swimming microorganisms by surfaces

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    Cells swimming in confined environments are attracted by surfaces. We measure the steady-state distribution of smooth-swimming bacteria (Escherichia coli) between two glass plates. In agreement with earlier studies, we find a strong increase of the cell concentration at the boundaries. We demonstrate theoretically that hydrodynamic interactions of the swimming cells with solid surfaces lead to their re-orientation in the direction parallel to the surfaces, as well as their attraction by the closest wall. A model is derived for the steady-state distribution of swimming cells, which compares favorably with our measurements. We exploit our data to estimate the flagellar propulsive force in swimming E. coli

    Delayed triggering of radio Active Galactic Nuclei in gas-rich minor mergers in the local Universe

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    This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © : 2016 [S. S. Shabala, a. Deller, S. Kaviraj, E. Middelberg, R. J. Turner, Y. S. Ting, J. R. Allison, T. A Davis, 'Delayed triggering of radio active galactic nucle in gas-rich minor mergers in the local Universe', MNRAS (2016) 464(4): 4706-4720]. The final, published version is available online via doi: https://doi.org/10.1093/mnras/stw2536 Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.We examine the processes triggering star formation and Active Galactic Nucleus (AGN) activity in a sample of 25 low redshift (z107z 10^7 K) brightness temperature required for an mJIVE-20 detection allows us to unambiguously identify the radio AGN in our sample. We find three such objects. Our VLBI AGN identifications are classified as Seyferts or LINERs in narrow line optical diagnostic plots; mid-infrared colours of our targets and the comparison of Hα\alpha star formation rates with integrated radio luminosity are also consistent with the VLBI identifications. We reconstruct star formation histories in our galaxies using optical and UV photometry, and find that these radio AGN are not triggered promptly in the merger process, consistent with previous findings for non-VLBI samples of radio AGN. This delay can significantly limit the efficiency of feedback by radio AGN triggered in galaxy mergers. We find that radio AGN hosts have lower star formation rates than non-AGN radio-selected galaxies at the same starburst age. Conventional and VLBI radio imaging shows these AGN to be compact on arcsecond scales. Our modeling suggests that the actual sizes of AGN-inflated radio lobes may be much larger than this, but these are too faint to be detected in existing observations. Deep radio imaging is required to map out the true extent of the AGN, and to determine whether the low star formation rates in radio AGN hosts are a result of the special conditions required for radio jet triggering, or the effect of AGN feedback.Peer reviewe

    Outer radiation belt and inner magnetospheric response to sheath regions of coronal mass ejections : a statistical analysis

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    The energetic electron content in the Van Allen radiation belts surrounding the Earth can vary dramatically at several timescales, and these strong electron fluxes present a hazard for spacecraft traversing the belts. The belt response to solar wind driving is, however, largely unpredictable, and the direct response to specific large-scale heliospheric structures has not been considered previously. We investigate the immediate response of electron fluxes in the outer belt that are driven by sheath regions preceding interplanetary coronal mass ejections and the associated wave activity in the inner magnetosphere. We consider the events recorded from 2012 to 2018 in the Van Allen Probes era to utilise the energy- and radial-distance-resolved electron flux observations of the twin spacecraft mission. We perform a statistical study of the events by using the superposed epoch analysis in which the sheaths are superposed separately from the ejecta and resampled to the same average duration. Our results show that the wave power of ultra-low frequency Pc5 and electromagnetic ion cyclotron waves, as measured by a Geostationary Operational Environmental Satellite (GOES), is higher during the sheath than during the ejecta. However, the level of chorus wave power, as measured by the Van Allen Probes, remains approximately the same due to similar substorm activity during the sheath and ejecta. Electron flux enhancements are common at low energies ( 4). It is distinctive that the depletion extends to lower energies at larger distances. We suggest that this L-shell and energy-dependent depletion results from the magnetopause shadowing that dominates the losses at large distances, while the wave-particle interactions dominate closer to the Earth. We also show that non-geoeffective sheaths cause significant changes in the outer belt electron fluxes.Peer reviewe

    Self-Reported Sleep Apnea and Dementia Risk: Findings from the Prevention of Alzheimer\u27s Disease with Vitamin E and Selenium Trial

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    OBJECTIVES: To investigate the association between baseline sleep apnea and risk of incident dementia in the Prevention of Alzheimer\u27s Disease with Vitamin E and Selenium (PREADViSE) study and to explore whether the association depends on apolipoprotein E (APOE) ɛ4 allele status. DESIGN: Secondary analysis based on data collected during PREADViSE. SETTING: Participants were assessed at 128 local clinical study sites during the clinical trial phase and later were followed by telephone from a centralized location. PARTICIPANTS: Men enrolled in PREADViSE (without dementia or other active neurological conditions that affect cognition such as major psychiatric disorders, including depression; N = 7,547). MEASUREMENTS: Participants were interviewed at baseline for sleep apnea. The Memory Impairment Screen (MIS) was administered to each participant annually. Subjects who failed this initial screen were tested with secondary screening tests. Medical history and medication use were determined, and the AD8 dementia screening instrument was used. RESULTS: The effect of self-reported sleep apnea on dementia risk depended on APOE ɛ4 status. When the allele was absent, baseline self-reported sleep apnea was associated with a 66% higher risk of developing dementia (95% confidence interval = 2-170%), whereas self-reported sleep apnea conferred no additional risk for participants with an ɛ4 allele. CONCLUSION: Sleep apnea may increase risk of dementia in the absence of APOE ɛ4. This may help inform prevention strategies for dementia or AD in older men with sleep apnea. Registration: PREADViSE is registered at ClinicalTrials.gov: NCT00040378

    Circulating HPV DNA as a Biomarker for Pre-Invasive and Early Invasive Cervical Cancer: A Feasibility Study

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    BACKGROUND: High-risk HPV infection is responsible for >99% of cervix cancers (CC). In persistent infections that lead to cancer, the tumour breaches the basement membrane, releasing HPV-DNA into the bloodstream (cHPV-DNA). A next-generation sequencing assay (NGS) for detection of plasma HPV circulating DNA (cHPV-DNA) has demonstrated high sensitivity and specificity in patients with locally advanced cervix cancers. We hypothesised that cHPV-DNA is detectable in early invasive cervical cancers but not in pre-invasive lesions (CIN). METHODS: Blood samples were collected from patients with CIN (n = 52) and FIGO stage 1A-1B CC (n = 12) prior to treatment and at follow-up. DNA extraction from plasma, followed by NGS, was used for the detection of cHPV-DNA. RESULTS: None of the patients with pre-invasive lesions were positive for CHPV-DNA. In invasive tumours, plasma from one patient (10%) reached the threshold of positivity for cHPV-DNA in plasma. CONCLUSION: Low detection of cHPV-DNA in early CC may be explained by small tumour size, poorer access to lymphatics and circulation, and therefore little shedding of cHPV-DNA in plasma at detectable levels. The detection rate of cHPV-DNA in patients with early invasive cervix cancer using even the most sensitive of currently available technologies lacks adequate sensitivity for clinical utility

    A New Independent Limit on the Cosmological Constant/Dark Energy from the Relativistic Bending of Light by Galaxies and Clusters of Galaxies

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    We derive new limits on the value of the cosmological constant, Λ\Lambda, based on the Einstein bending of light by systems where the lens is a distant galaxy or a cluster of galaxies. We use an amended lens equation in which the contribution of Λ\Lambda to the Einstein deflection angle is taken into account and use observations of Einstein radii around several lens systems. We use in our calculations a Schwarzschild-de Sitter vacuole exactly matched into a Friedmann-Robertson-Walker background and show that a Λ\Lambda-contribution term appears in the deflection angle within the lens equation. We find that the contribution of the Λ\Lambda-term to the bending angle is larger than the second-order term for many lens systems. Using these observations of bending angles, we derive new limits on the value of Λ\Lambda. These limits constitute the best observational upper bound on Λ\Lambda after cosmological constraints and are only two orders of magnitude away from the value determined by those cosmological constraints.Comment: 5 pages, 1 figure, matches version published in MNRA

    Surface engineering of porous silicon to optimise therapeutic antibody loading and release

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    Open Access Article. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.The proinflammatory cytokine, tumor necrosis factor-α (TNF-α), is elevated in several diseases such as uveitis, rheumatoid arthritis and non-healing chronic wounds. Adding Infliximab, a chimeric IgG1 monoclonal antibody raised against TNF-α, to chronic wound fluid can neutralise human TNF-α, thereby providing a potential therapeutic option for chronic wound healing. However, to avoid the need for repeated application in a clinical setting, and to protect the therapeutic antibody from the hostile environment of the wound, suitable delivery vehicles are required. Porous silicon (pSi) is a biodegradable high surface area material commonly employed for drug delivery applications. In this study, the use of pSi microparticles (pSi MPs) for the controlled release of Infliximab to disease environments, such as chronic wounds, is demonstrated. Surface chemistry and pore parameters for Infliximab loading are first optimised in pSi films and loading conditions are transferred to pSi MPs. Loading regimens exceeding 60 μg of Infliximab per mg of pSi are achieved. Infliximab is released with zero-order release kinetics over the course of 8 days. Critically, the released antibody remains functional and is able to sequester TNF-α over a weeklong timeframe; suitable for a clinical application in chronic wound therapy
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