5,600 research outputs found

    Probabilistic modeling of one dimensional water movement and leaching from highway embankments containing secondary materials

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    Predictive methods for contaminant release from virgin and secondary road construction materials are important for evaluating potential long-term soil and groundwater contamination from highways. The objective of this research was to describe the field hydrology in a highway embankment and to investigate leaching under unsaturated conditions by use of a contaminant fate and transport model. The HYDRUS2D code was used to solve the Richards equation and the advection–dispersion equation with retardation. Water flow in a Minnesota highway embankment was successfully modeled in one dimension for several rain events after Bayesian calibration of the hydraulic parameters against water content data at a point 0.32 m from the surface of the embankment. The hypothetical leaching of Cadmium from coal fly ash was probabilistically simulated in a scenario where the top 0.50 m of the embankment was replaced by coal fly ash. Simulation results were compared to the percolation equation method where the solubility is multiplied by the liquid-to-solid ratio to estimate total release. If a low solubility value is used for Cadmium, the release estimates obtained using the percolation/equilibrium model are close to those predicted from HYDRUS2D simulations (10–4–10–2 mg Cd/kg ash). If high solubility is used, the percolation equation over predicts the actual release (0.1–1.0 mg Cd/kg ash). At the 90th percentile of uncertainty, the 10-year liquid-to-solid ratio for the coal fly ash embankment was 9.48 L/kg, and the fraction of precipitation that infiltrated the coal fly ash embankment was 92%. Probabilistic modeling with HYDRUS2D appears to be a promising realistic approach to predicting field hydrology and subsequent leaching in embankments

    Improved Lower-Arm Prosthesis

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    Over the past few decades, innovations in myoelectric sensing in upper limb prostheses have given systems the ability to read, detect, and emulate fine motor control in an increasingly realistic manner. However, the practical impact that these scientific accomplishments yield is significantly limited by the lack of adoption witnessed by patients who are given such prosthetics. Some people see the device as a burden rather than an improvement. To address this issue, we propose the development of an improved lower arm prosthesis. This prosthesis is intended to encourage patient adoption and retention by emphasizing simplicity and comfort over technical precision. Our project has the ability to change one’s lifestyle. It’s significance can change a person’s life from living with one hand to now being able to use both. The importance to us as a group is not only to build a successful hand and learn something from it but also to make it successful, i.e. comfortable, reliable and low cost. We believe that we can positively impact an amputees life. The design of this prosthetic will be centered around: less weight, comfort, and low cost. An electromyographic (EMG) sensing system will be incorporated into our design. This system measures the electric signals emitted from the muscles of the user’s upper¬limb during attempted movement. Based on these read¬in micro¬voltages, a ZYBO Zynq¬7000 development board will be used to electrically control motors that manipulate string¬based tendons which control the hand. The comfort of the prosthesis will be optimized through the use of an adjustable elbow brace¬like attachment outfitted with breathable materials. We plan to construct a functioning hand that has an easy adaptability learning curve for the user.https://scholarscompass.vcu.edu/capstone/1046/thumbnail.jp

    Finding AGN in Deep X-ray Flux States with Swift

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    We report on our ongoing project of finding Active Galactic Nuclei (AGN) that go into deep X-ray flux states detected by Swift. Swift is performing an extensive study on the flux and spectral variability of AGN using Guest Investigator and team fill-in programs followed by triggering XMM_Newton for deeper follow-up observations. So far this program has been very successful and has led to a number of XMM-Newton follow up observations, including Mkn 335, PG 0844+349, and RX J2340.8-5329. Recent analysis of new Swift AGN observations reveal several AGN went into a very low X-ray flux state, particularly Narrow-Line Seyfert 1 galaxies. One of these is RX J2317-4422, which dropped by a factor of about 60 when compared to the ROSAT All-Sky Survey.Comment: 6 pages, 3 figures, Proceedings of the "10 Years of Swift" Meeting held in Rome in December 2014. Submitted to Po

    Visual enhancement of touch and the bodily self

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    We experience our own body through both touch and vision. We further see that others’ bodies are similar to our own body, but we have no direct experience of touch on others’ bodies. Therefore, relations between vision and touch are important for the sense of self and for mental representation of one’s own body. For example, seeing the hand improves tactile acuity on the hand, compared to seeing a non-hand object. While several studies have demonstrated this visual enhancement of touch (VET) effect, its relation to the ‘bodily self’, or mental representation of one’s own body remains unclear. We examined whether VET is an effect of seeing a hand, or of seeing my hand, using the rubber hand illusion. In this illusion, a prosthetic hand which is brushed synchronously—but not asynchronously—with one’s own hand is felt to actually be one’s hand. Thus, we manipulated whether or not participants felt like they were looking directly at their hand, while holding the actual stimulus they viewed constant. Tactile acuity was measured by having participants judge the orientation of square-wave gratings. Two characteristic effects of VET were observed: (1) cross-modal enhancement from seeing the hand was inversely related to overall tactile acuity, and (2) participants near sensory threshold showed significant improvement following synchronous stroking, compared to asynchronous stroking or no stroking at all. These results demonstrate a clear functional relation between the bodily self and basic tactile perception

    Quantum dynamics under coherent and incoherent effects of a spin bath in the Keldysh formalism: application to a spin swapping operation

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    We develop the Keldysh formalism for the polarization dynamics of an open spin system. We apply it to the swapping between two qubit states in a model describing an NMR cross-polarization experiment. The environment is a set of interacting spins. For fast fluctuations in the environment, the analytical solution shows effects missed by the secular approximation of the Quantum Master Equation for the density matrix: a frequency decrease depending on the system-environment escape rate and the quantum quadratic short time behavior. Considering full memory of the bath correlations yields a progressive change of the swapping frequency.Comment: 16 pages, 3 figures, final for

    Rapid enhancement of touch from non-informative vision of the hand

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    Processing in one sensory modality may modulate processing in another. Here we investigate how simply viewing the hand can influence the sense of touch. Previous studies showed that non-informative vision of the hand enhances tactile acuity, relative to viewing an object at the same location. However, it remains unclear whether this Visual Enhancement of Touch (VET) involves a phasic enhancement of tactile processing circuits triggered by the visual event of seeing the hand, or more prolonged, tonic neuroplastic changes, such as recruitment of additional cortical areas for tactile processing. We recorded somatosensory evoked potentials (SEPs) evoked by electrical stimulation of the right middle finger, both before and shortly after viewing either the right hand, or a neutral object presented via a mirror. Crucially, and unlike prior studies, our visual exposures were unpredictable and brief, in addition to being non-informative about touch. Viewing the hand, as opposed to viewing an object, enhanced tactile spatial discrimination measured using grating orientation judgements, and also the P50 SEP component, which has been linked to early somatosensory cortical processing. This was a trial-specific, phasic effect, occurring within a few seconds of each visual onset, rather than an accumulating, tonic effect. Thus, somatosensory cortical modulation can be triggered even by a brief, non-informative glimpse of one’s hand. Such rapid multisensory modulation reveals novel aspects of the specialised brain systems for functionally representing the body

    The Grizzly, August 31, 2006

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    Rebirth of Zack\u27s • Internet Outage on Campus • Changes to Parking on Campus • Class of 2010 Moves In • Sex at Ursinus • Getting to Know Ursinus • Local Dining Delights • Experiencing the Journey • Opinions: Save the Moderates; Opinions Editors Opinions on Opinions; Election Projections • Talent and Experience Lead Bears Into 2006 Season • Field Hockey Looks to Continue Dominance in CChttps://digitalcommons.ursinus.edu/grizzlynews/1715/thumbnail.jp

    Single-mitosis dissection of acute and chronic DNA mutagenesis and repair

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    How chronic mutational processes and punctuated bursts of DNA damage drive evolution of the cancer genome is poorly understood. Here, we demonstrate a strategy to disentangle and quantify distinct mechanisms underlying genome evolution in single cells, during single mitoses and at single-strand resolution. To distinguish between chronic (reactive oxygen species (ROS)) and acute (ultraviolet light (UV)) mutagenesis, we microfluidically separate pairs of sister cells from the first mitosis following burst UV damage. Strikingly, UV mutations manifest as sister-specific events, revealing mirror-image mutation phasing genome-wide. In contrast, ROS mutagenesis in transcribed regions is reduced strand agnostically. Successive rounds of genome replication over persisting UV damage drives multiallelic variation at CC dinucleotides. Finally, we show that mutation phasing can be resolved to single strands across the entire genome of liver tumors from F1 mice. This strategy can be broadly used to distinguish the contributions of overlapping cancer relevant mutational processes

    The Grizzly, August 30, 2007

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    Ursinus Opens the New Building on the Block • Ursinus Battles U.S. News: Interview with President Strassburger • Sex at Ursinus • Who are the New RDs? • Spotlight: Student Emergency Response Volunteers (SERV) • Fresh Faces at Ursinus • Opinions: Freeganism: The New, Gentle Face of Anarchy; Global Warming: Modern Day Witch Hunt • Dubble Vision: Football Forecast • Ready, Set, Go Bears!https://digitalcommons.ursinus.edu/grizzlynews/1740/thumbnail.jp

    In search of phylogenetic congruence between molecular and morphological data in bryozoans with extreme adult skeletal heteromorphy

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    peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=tsab20© Crown Copyright 2015. This document is the author's final accepted/submitted version of the journal article. You are advised to consult the publisher's version if you wish to cite from it
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