513 research outputs found

    Boilerplate and Party Intent

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    In this work we examined optical and defect properties of as-grown and Ni-coated ZnO nanowires (NWs) grown by rapid thermal chemical vapor deposition by means of optically detected magnetic resonance (ODMR). Several grown-in defects are revealed by monitoring visible photoluminescence (PL) emissions and are attributed to Zn vacancies, O vacancies, a shallow (but not effective mass) donor and exchange-coupled pairs of a Zn vacancy and a Zn interstitial. It is also found that the same ODMR signals are detected in the as-grown and Ni-coated NWs, indicating that metal coatings does not significantly affect formation of the aforementioned defects and that the observed defects are located in the bulk of the NWs

    Ensuring Security and Availability through Model-Based Cross-Layer Adaptation

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    Abstract. Situation- and resource-aware security is essential for the process control systems, composed of networked entities with sensors and actuators, that monitor and control the national critical infrastructure. However, security cannot be addressed at a single layer because of the inherent dependencies and tradeoffs among crosscutting concerns. Tech-niques applied at one layer to improve security affect security, timing, and power consumption at other layers. This paper argues for an integrated treatment of security across multiple layers of abstraction (application, middleware, operating system including network stack, and hardware). An important step in realizing this integrated treatment of situation-and resource-aware security is first understanding the cross-layer inter-actions between security policies and then exploiting these interactions to design efficient adaptation strategies (i) to balance security, quality of service, and energy needs, and (ii) to maximize system availability. We propose a novel approach that employs a compositional method within an iterative tuning framework based on lightweight formal methods with dynamic adaptation.

    Knowledge politics and new converging technologies: a social epistemological perspective

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    The ā€œnew converging technologiesā€ refers to the prospect of advancing the human condition by the integrated study and application of nanotechnology, biotechnology, information technology and the cognitive sciences - or ā€œNBICā€. In recent years, it has loomed large, albeit with somewhat different emphases, in national science policy agendas throughout the world. This article considers the political and intellectual sources - both historical and contemporary - of the converging technologies agenda. Underlying it is a fluid conception of humanity that is captured by the ethically challenging notion of ā€œenhancing evolutionā€

    Fiscal and Policy Implications of Selling Pipe Tobacco for Roll-Your-Own Cigarettes in the United States

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    The Federal excise tax was increased for tobacco products on April 1, 2009. While excise tax rates prior to the increase were the same for roll-your-own (RYO) and pipe tobacco, the tax on pipe tobacco was 21.95perpoundlessthanthetaxonRYOtobaccoaftertheincrease.Subsequently,tobaccomanufacturersbeganlabelingloosetobaccoaspipetobaccoandmarketingtheseproductstoRYOconsumersatalowerprice.Retailersrefertotheseproductsasā€œdualpurpose"orā€œdualuse"pipetobacco.DataontobaccotaxcollectionscomesfromtheAlcoholandTobaccoTaxandTradeBureau.Joinpointsoftwarewasusedtoidentifychangesinsalestrends.EstimatesweregeneratedfortheamountofpipetobaccosoldforRYOuseandforFederalandstatetaxrevenuelostthroughAugust2011.Approximately45millionpoundsofpipetobaccohasbeensoldforRYOusefromApril2009toAugust2011,loweringstateandFederalrevenuebyover21.95 per pound less than the tax on RYO tobacco after the increase. Subsequently, tobacco manufacturers began labeling loose tobacco as pipe tobacco and marketing these products to RYO consumers at a lower price. Retailers refer to these products as ā€œdual purpose" or ā€œdual use" pipe tobacco.Data on tobacco tax collections comes from the Alcohol and Tobacco Tax and Trade Bureau. Joinpoint software was used to identify changes in sales trends. Estimates were generated for the amount of pipe tobacco sold for RYO use and for Federal and state tax revenue lost through August 2011.Approximately 45 million pounds of pipe tobacco has been sold for RYO use from April 2009 to August 2011, lowering state and Federal revenue by over 1.3 billion.Marketing pipe tobacco as ā€œdual purpose" and selling it for RYO use provides an opportunity to avoid paying higher cigarette prices. This blunts the public health impact excise tax increases would otherwise have on reducing tobacco use through higher prices. Selling pipe tobacco for RYO use decreases state and Federal revenue and also avoids regulations on flavored tobacco, banned descriptors, prohibitions on shipping, and reporting requirements

    Alterations in vascular function in primary aldosteronism - a cardiovascular magnetic resonance imaging study

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    Introduction: Excess aldosterone is associated with increased cardiovascular risk. Aldosterone has a permissive effect on vascular fibrosis. Cardiovascular magnetic resonance imaging (CMR) allows study of vascular function by measuring aortic distensibility. We compared aortic distensibility in primary aldosteronism (PA), essential hypertension (EH) and normal controls and explored the relationship between aortic distensibility and pulse wave velocity (PWV).<p></p> Methods: We studied PA (n=14) and EH (n=33) subjects and age-matched healthy controls (n=17) with CMR, including measurement of aortic distensibility, and measured PWV using applanation tonometry. At recruitment, PA and EH patients had similar blood pressure and left ventricular mass.<p></p> Results: Subjects with PA had significantly lower aortic distensibilty and higher PWV compared to EH and healthy controls. These changes were independent of other factors associated with reduced aortic distensibility, including aging. There was a significant relationship between increasing aortic stiffness and age in keeping with physical and vascular aging. As expected, aortic distensibility and PWV were closely correlated.<p></p> Conclusion: These results demonstrate that PA patients display increased arterial stiffness compared to EH, independent of vascular aging. The implication is that aldosterone invokes functional impairment of arterial function. The long-term implications of arterial stiffening in aldosterone excess require further study.<p></p&gt

    A Transaction Cost Economizing Approach to Regulation: Understanding the NIMBY Problem and Improving Regulatory Responses

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    This paper develops a transaction cost economic model for regulation and applies the model to environmental siting regulations designed to overcome NIMBY (Not In My Back Yard) political opposition. Negotiations between developers and resistant local communities to site waste facilities, such as landfills or solid waste incinerators, can be characterized as a contracting problem. A rudimentary application of the Coase theorem suggests that developers should be able to compensate communities adequately for hosting a waste facility, but rarely do such negotiations find success. Transaction costs associated with the requisite negotiations, communication, and implementation of the projects preclude efficient bargaining, and thus NIMBY opposition halts the siting of socially necessary and beneficial facilities. Viewing NIMBY disputes as a contracting problem within the world of positive transaction costs therefore reveals the dynamics that foil negotiations between developers and communities. Such a perspective also identifies the role that the theory of the firm can play in understanding how siting regulations overcome those transaction costs and how regulatory regimes can be optimally designed for siting alternative facilities. This paper employs the theory of the firm, specifically transaction cost economics, to articulate the functional purpose of environmental siting regulations and to chart an agenda for regulatory reform. While transaction cost economics traditionally compares mechanisms such as spot markets, contracts, and direct ownership to facilitate economic transactions, we extend transaction cost theory to political transactions between policymakers and initially resistant, though potentially supportive, constituencies. We believe this approach offers a fruitful perspective on regulatory policy. We use it to develop a taxonomy of alternative regulatory regimes and then to propose an overview of regulatory reform for siting socially desirable waste facilities that are either blocked by NIMBY opposition or are unnecessarily shielded from effective negotiations and community participation

    Accelerated Hydrolysis of Aspirin Using Alternating Magnetic Fields

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    The major problem of current drug-based therapy is selectivity. As in other areas of science, a combined approach might improve the situation decisively. The idea is to use the pro-drug principle together with an alternating magnetic field as physical stimulus, which can be applied in a spatially and temporarily controlled manner. As a proof of principle, the neutral hydrolysis of aspirin in physiological phosphate buffer of pH 7.5 at 40 Ā°C was chosen. The sensor and actuator system is a commercially available gold nanoparticle (NP) suspension which is approved for animal usage, stable in high concentrations and reproducibly available. Applying the alternating magnetic field of a conventional NMR magnet system accelerated the hydrolysis of aspirin in solution
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