2,225 research outputs found

    Influence of barium on rectification in rat neocortical neurons

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    The effect of low concentrations of barium on the membrane properties of rat neocortical neurons was studied in vitro. Potassium currents were examined using single-electrode current- and voltage-clamp techniques. Neurons responded to bath application of barium (10–100 ÎŒM) with a membrane depolarization associated with an increase in input resistance. Under voltage clamp conditions, an inward shift in holding current was observed. The effects of barium were rapidly reversible upon washing and persisted in the presence of TTX. The equilibrium potential for the barium-induced inward current was near −110 mV, suggesting that barium inhibited a tonically active potassium conductance. Measurements of current voltage relationships indicated an inward rectification of this conductance between −50 and −130 mV. These results provide strong evidence that barium blocks a persistent potassium ‘leak’ current in neocortical neurons that contributes to the resting potential of these cells

    Variational Calculation for the Equation of State of Nuclear Matter at Finite Temperatures

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    An equation of state (EOS) for uniform nuclear matter is constructed at zero and finite temperatures with the variational method starting from the realistic nuclear Hamiltonian composed of the Argonne V18 and UIX potentials. The energy is evaluated in the two-body cluster approximation with the three-body-force contribution treated phenomenologically so as to reproduce the empirical saturation conditions. The obtained energies for symmetric nuclear matter and neutron matter at zero temperature are in fair agreement with those by Akmal, Pandharipande and Ravenhall, and the maximum mass of the neutron star is 2.2 Msolar. At finite temperatures, a variational method by Schmidt and Pandharipande is employed to evaluate the free energy, which is used to derive various thermodynamic quantities of nuclear matter necessary for supernova simulations. The result of this variational method at finite temperatures is found to be self-consistent.Comment: Revised Versio

    HUD feedback to minimize the risk of cellular phone use and number entry while driving

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    There has been considerable public debate as to whether people should be allowed to use cell phones while driving. In several countries, this debate has led to restrictions on cell phone use while driving. Japanese data suggests that answering a call might be the most dangerous task, followed by dialing. Several questions were therefore selected for further investigation. 1. How does the dialing device and its location affect task time, errors, driving performance, and ratings of workload? 2. How does the location of the display (especially head-up displays) affect those same measures? 3. For various control-display combinations, how are those measures affected by driving workload? The experiment will be comprised of two distinct portions. In the first portion, subjects will drive a simulator on straight roads (implying controlled workload) while dialing a 10-digit telephone number using 6 device configurations with various displays. During the second test portion, participants will drive a simulator on roads with curves of different radii while entering phone numbers for 3 different device combinations. The following device/location configurations will be examined: (1) 10-key keypad on the steering wheel spoke, (2) 10-key keypad on the center console, (3) joystick on the steering wheel spoke, (4) joystick mounted on the center console, (5) hand held 10- key keypad, (6) a cross key on the touch screen, and (7) a 10 key keypad on the touch screen. These devices will be used for 3 display conditions: (1) head up display, (2) monitor mounted in the center console, or (3) no display.Nissan Research Centerhttp://deepblue.lib.umich.edu/bitstream/2027.42/92345/1/102881.pd

    Dark Patterns at Scale: Findings from a Crawl of 11K Shopping Websites

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    Dark patterns are user interface design choices that benefit an online service by coercing, steering, or deceiving users into making unintended and potentially harmful decisions. We present automated techniques that enable experts to identify dark patterns on a large set of websites. Using these techniques, we study shopping websites, which often use dark patterns to influence users into making more purchases or disclosing more information than they would otherwise. Analyzing ~53K product pages from ~11K shopping websites, we discover 1,818 dark pattern instances, together representing 15 types and 7 broader categories. We examine these dark patterns for deceptive practices, and find 183 websites that engage in such practices. We also uncover 22 third-party entities that offer dark patterns as a turnkey solution. Finally, we develop a taxonomy of dark pattern characteristics that describes the underlying influence of the dark patterns and their potential harm on user decision-making. Based on our findings, we make recommendations for stakeholders including researchers and regulators to study, mitigate, and minimize the use of these patterns.Comment: 32 pages, 11 figures, ACM Conference on Computer-Supported Cooperative Work and Social Computing (CSCW 2019

    The Geometry and Moduli of K3 Surfaces

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    These notes will give an introduction to the theory of K3 surfaces. We begin with some general results on K3 surfaces, including the construction of their moduli space and some of its properties. We then move on to focus on the theory of polarized K3 surfaces, studying their moduli, degenerations and the compactification problem. This theory is then further enhanced to a discussion of lattice polarized K3 surfaces, which provide a rich source of explicit examples, including a large class of lattice polarizations coming from elliptic fibrations. Finally, we conclude by discussing the ample and Kahler cones of K3 surfaces, and give some of their applications.Comment: 34 pages, 2 figures. (R. Laza, M. Schutt and N. Yui, eds.

    On the new economic philosophy of crisis management in the European Union

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    This essay attempts to go beyond presenting the bits and pieces of still ongoing crisis management in the EU. Instead it attempts at finding the ‘red thread’ behind a series of politically improvised decisions. Our fundamental research question asks whether basic economic lessons learned in the 1970s are still valid. Namely, that a crises emanating from either structural or regulatory weaknesses cannot and should not be remedied by demand management. Our second research question is the following: Can lacking internal commitment and conviction in any member state be replaced or substituted by external pressure or formalized procedures and sanctions? Under those angles we analyze the project on establishing a fiscal and banking union in the EU, as approved by the Council in December 2012

    Dermatological cancer screening: Evaluation of a new community pharmacy service

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    Background: Skin cancer accounts for one third of all cancers. Prognosis is inversely related to identification stage. Objectives: To describe a novel service, mole scans, performed in community pharmacy, the findings from the first 3.5 years it was in place, and to explore patient acceptability of the service. Methods: Norwegian Boots' pharmacies offer a mole scanning service in cooperation with ScreenCancer. Scans are undertaken within pharmacy consultation rooms. Image interpretation is undertaken remotely by a specialist. Number and result of scans performed from 2010 to 2014 are reported. A satisfaction questionnaire was returned by 10% of participants. Results: A total of 25836 scans were performed on 15777 individuals. Of these, 83.6% had normal scans, 1% had melanoma, and 15.4% had another skin condition. In 2014 the service identified 4.1% of melanoma cases registered in the Norwegian Cancer Registry. Most responders (88%) would use a similar service again. Nearly all (99%) felt the pharmacy was a suitable venue, and 95% would recommend the service to others. In total, 99% of respondents scored their overall satisfaction as “good” or higher. Conclusions: This approach was acceptable among participants who provided feedback. Providing mole scanning through pharmacies enables individuals to obtain a rapid check of moles causing concern, in an acceptable environment with a high level of satisfaction

    Lifespan theorem for constrained surface diffusion flows

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    We consider closed immersed hypersurfaces in R3\R^{3} and R4\R^4 evolving by a class of constrained surface diffusion flows. Our result, similar to earlier results for the Willmore flow, gives both a positive lower bound on the time for which a smooth solution exists, and a small upper bound on a power of the total curvature during this time. By phrasing the theorem in terms of the concentration of curvature in the initial surface, our result holds for very general initial data and has applications to further development in asymptotic analysis for these flows.Comment: 29 pages. arXiv admin note: substantial text overlap with arXiv:1201.657
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