512 research outputs found

    Oscillation and Repetitive Firing in Squid Axons

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    Space-clamped squid axons treated with low calcium and computed Hodgkin-Huxley (HH) axons were stimulated by steps of superthreshold current from 101 to 400% of the rheobasic value over a temperature range of 5–27°C. The natural frequency of sustained repetitive firing of real and computed axons depended weakly upon stimulus intensity and strongly upon temperature, with a Q10 of 2.7 (experimental) and 2.6 (computed). For real axons, but not the computed axon, the intervals between the first two spikes were shorter than between subsequent spikes. Constant spike frequencies from 75 Hz at low intensities and temperatures to 330 Hz at high intensities and temperatures were soon achieved. Subthreshold and superthreshold responses were sometimes intermixed in a train of responses from a real axon responding to a constant step of current, but not predicted by HH. The time interval following a spike was always longer than that following a subthreshold oscillation in slightly decalcified real axons, as Huxley and FitzHugh also found for computed axons. There was a bias toward spikes at the beginning of the train and toward subthreshold responses later on. Some repeated patterns were found, every second, third, or fourth response being a spike. Neither the HH equations nor the computed or experimental threshold behaviors show a critical temperature to support a membrane phase transition

    Is Money No Object: Can the Government Rely on Financial Considerations Under Charter Section 1

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    Government programs have increasingly been challenged under the Charter on the grounds that they are provided inappropriately to a limited number of beneficiaries and that the benefits provided are set at insufficient levels. Courts have thus been asked to determine how governments should allocate finite resources in a world of infinite need. In this paper, the authors explore the question of the place of financial considerations for the purposes of section 1 of the Charter. In Martin (2003), the government of Nova Scotia attempted to rely on financial considerations in order to justify the exclusion of chronic pain sufferers from the regular compensation scheme provided by the Workers’ Compensation Act. Relying on dicta from the Schachter (1992) and Judges’ Reference (1997) decisions, the Supreme Court dismissed this argument and held that budgetary considerations could not be put forward by governments as a free-standing pressing and substantial objective for the purposes of section 1 of the Charter. However, the Court also acknowledged that “in certain circumstances”, financial considerations may constitute a pressing and substantial objective. The Court found it unnecessary to decide this point in Martin, and the question remains unanswered. Using examples from tort and administrative law, as well as lower court Charter decisions, the authors argue that courts cannot ignore the realities imposed on governments by fiscal limitations. If courts take on a greater role in policy-making, they must give serious consideration not only to arguments based on financial considerations, but also to the financial implications of their decisions

    Merchant differentiation through integrative negotiation in agent-mediated electronic commerce

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    Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 1998.Includes bibliographical references (p. [149]-153).This thesis proposes to fix online shopping by guiding it away from price comparisons and toward value comparisons. Though price comparisons may be adequate for simple products (e.g., books and music), they are inadequate for facilitating transactions of complex products (e.g., computers and automobiles). Consumers often must consider qualities other than price in their buying decisions and merchants usually prefer to differentiate themselves along alternative dimensions such as brand, customer service, delivery time, warranty, and other value-added services. Tete-a-Tete is an agent-mediated comparison shopping system that allows consumers to consider dimensions other than price in their buying decisions for complex products. The system helps shoppers answer two questions: what to buy and who to buy from. Tete-a- Tete's integrative negotiation interaction model (based on bilateral argumentation), together with a decision support module (based on multi-attribute utility theory), create an improved online shopping environment for both consumers and merchants. Consumers gain increased satisfaction as their search costs for complex products are reduced and merchants potentially increase sales as a result of their enhanced differentiation in the marketplace.Robert H. Guttman.S.M

    The Detection of Ionizing Radiation by Plasma Panel Sensors: Cosmic Muons, Ion Beams and Cancer Therapy

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    The plasma panel sensor is an ionizing photon and particle radiation detector derived from PDP technology with high gain and nanosecond response. Experimental results in detecting cosmic ray muons and beta particles from radioactive sources are described along with applications including high energy and nuclear physics, homeland security and cancer therapeuticsComment: Presented at SID Symposium, June 201

    Plasma Panel Sensors for Particle and Beam Detection

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    The plasma panel sensor (PPS) is an inherently digital, high gain, novel variant of micropattern gas detectors inspired by many operational and fabrication principles common to plasma display panels (PDPs). The PPS is comprised of a dense array of small, plasma discharge, gas cells within a hermetically-sealed glass panel, and is assembled from non-reactive, intrinsically radiation-hard materials such as glass substrates, metal electrodes and mostly inert gas mixtures. We are developing the technology to fabricate these devices with very low mass and small thickness, using gas gaps of at least a few hundred micrometers. Our tests with these devices demonstrate a spatial resolution of about 1 mm. We intend to make PPS devices with much smaller cells and the potential for much finer position resolutions. Our PPS tests also show response times of several nanoseconds. We report here our results in detecting betas, cosmic-ray muons, and our first proton beam tests.Comment: 2012 IEEE NS

    Development of a plasma panel radiation detector: recent progress and key issues

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    A radiation detector based on plasma display panel technology, which is the principal component of plasma television displays is presented. Plasma Panel Sensor (PPS) technology is a variant of micropattern gas radiation detectors. The PPS is conceived as an array of sealed plasma discharge gas cells which can be used for fast response (O(5ns) per pixel), high spatial resolution detection (pixel pitch can be less than 100 micrometer) of ionizing and minimum ionizing particles. The PPS is assembled from non-reactive, intrinsically radiation-hard materials: glass substrates, metal electrodes and inert gas mixtures. We report on the PPS development program, including simulations and design and the first laboratory studies which demonstrate the usage of plasma display panels in measurements of cosmic ray muons, as well as the expansion of experimental results on the detection of betas from radioactive sources.Comment: presented at IEEE NSS 2011 (Barcelona

    Greening Real Estate Professionals: A Model for Landowner Engagement through Effective Education for Brokers & Appraisers

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    Real estate brokers, appraisers, and developers are an essential audience for bridging communication with new landowners throughout the Salish Sea watershed. The majority of these professionals share concerns about protecting water quality, ensuring the health of theSalishSeafor recreation and economic vitality, and preventing activities that lead to anthropogenic-caused landslides, flooding and other disasters. Since 1998, WSU Extension has managed a real estate school focused on green topics to engage real estate professionals in these issues critical to their clients and our region\u27s water resources. In recent years, our focus has centered on the topics of Green Stormwater Infrastructure and Understanding Shoreline Processes/Stewardship Activities. Benefits of targeting this audience include: brokers may be or often work with small- to large-scale developers and can influence how development occurs; the sale/transfer of land is often at the nexus of re-development; educated brokers can inform their clientele on options for preventing pollution and undertaking stewardship practices; and appraisers need to incorporate proper valuation of mature vegetation, proper water management, and Green Stormwater Infrastructure for systemic change to occur. This poster will highlight the model of classroom and field-based learning that has been successful; what the audiences value as part of the workshop package; feedback about successes and shortcomings; openness and skepticism of this audience vis Ă  vis environmental issues, including climate change; and assessments of short- and mid-term impacts to increase awareness, understanding and acceptance for green stewardship practices for both stormwater management and living with and on shoreline/bluff properties

    Crosstalk between hemostasis inhibitors and cholesterol biomarkers in multiple sclerosis

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    The individual roles of cholesterol pathway biomarkers (CPB) and hemostasis inhibitors with neuroimaging outcomes were previously investigated in multiple sclerosis (MS). The purpose of this extension study was to investigate potential crosstalk between plasma CPB [total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and apolipoproteins (Apo) ApoA-I, ApoAII, ApoB, ApoC-II and ApoE] and hemostasis inhibitors [heparin cofactor-II (HCII), protein C (PC), protein S (PS), thrombomodulin, ADAMTS13 and PAI-1] in a cohort of 127 MS patients, and 40 healthy individuals (HI). The associations were assessed with regressions. In MS patients, HCII was positively associated with TC, LDL-C, HDL-C and ApoA-I (p=0.028, 0.027, 0.002 and 0.027, respectively) but negatively associated with ApoCII (p=0.018). PC was positively associated with ApoC-II (p=0.001) and ApoB (p=0.016) whereas PS was associated with TC (p=0.024) and ApoE (p=0.003) in MS. The ApoC-II associations were not observed in HI. The negative association between ApoC-II and HCll was an exception amongst other positive associations between CPB and hemostasis inhibitors in MS. CPB do not modulate the PC associations with neurodegeneration in MS

    IL-4Rα Blockade by Dupilumab Decreases Staphylococcus aureus Colonization and Increases Microbial Diversity in Atopic Dermatitis.

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    Dupilumab is a fully human antibody to interleukin-4 receptor α that improves the signs and symptoms of moderate to severe atopic dermatitis (AD). To determine the effects of dupilumab on Staphylococcus aureus colonization and microbial diversity on the skin, bacterial DNA was analyzed from swabs collected from lesional and nonlesional skin in a double-blind, placebo-controlled study of 54 patients with moderate to severe AD randomized (1:1) and treated with either dupilumab (200 mg weekly) or placebo for 16 weeks. Microbial diversity and relative abundance of Staphylococcus were assessed by DNA sequencing of 16S ribosomal RNA, and absolute S. aureus abundance was measured by quantitative PCR. Before treatment, lesional skin had lower microbial diversity and higher overall abundance of S. aureus than nonlesional skin. During dupilumab treatment, microbial diversity increased and the abundance of S. aureus decreased. Pronounced changes were seen in nonlesional and lesional skin. Decreased S. aureus abundance during dupilumab treatment correlated with clinical improvement of AD and biomarkers of type 2 immunity. We conclude that clinical improvement of AD that is mediated by interleukin-4 receptor α inhibition and the subsequent suppression of type 2 inflammation is correlated with increased microbial diversity and reduced abundance of S. aureus
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