8,345 research outputs found

    Advocacy coalitions involved in California's menu labeling policy debate: Exploring coalition structure, policy beliefs, resources, and strategies.

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    Advocacy coalitions often play an important role in the state health policymaking process, yet little is known about their structure, composition, and behavior. In 2008, California became the first state to enact a menu labeling law. Using the advocacy coalition framework, we examine different facets of the coalitions involved in California's menu labeling policy debate. We use a qualitative research approach to identify coalition members and explore their expressed beliefs and policy arguments, resources, and strategies by analyzing legislative documents (n = 87) and newspaper articles (n = 78) produced between 1999 and 2009. Between 2003 and 2008, six menu labeling bills were introduced in the state's legislature. We found the issue received increasing media attention during this period. We identified two advocacy coalitions involved in the debate-a public health (PH) coalition and an industry coalition. State organizations acted as coalition leaders and participated for a longer duration than elected officials. The structure and composition of each coalition varied. PH coalition leadership and membership notably increased compared to the industry coalition. The PH coalition, led by nonprofit PH and health organizations, promoted a clear and consistent message around informed decision making. The industry coalition, led by a state restaurant association, responded with cost and implementation arguments. Each coalition used various resources and strategies to advance desired outcomes. PH coalition leaders were particularly effective at using resources and employing advocacy strategies, which included engaging state legislators as coalition members, using public opinion polls and information, and leveraging media resources to garner support. Policy precedence and a local policy push emerged as important policymaking strategies. Areas for future research on the state health policymaking process are discussed

    Structural properties of silicon dioxide thin films densified by medium-energy particles

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    Classical molecular-dynamics simulations have been carried out to investigate densification mechanisms in silicon dioxide thin films deposited on an amorphous silica surface, according to a simplified ion-beam assisted deposition (IBAD) scenario. We compare the structures resulting from the deposition of near-thermal (1 eV) SiO2_{2} particles to those obtained with increasing fraction of 30 eV SiO2_{2} particles. Our results show that there is an energy interval - between 12 and 15 eV per condensing SiO2_2 unit on average - for which the growth leads to a dense, low-stress amorphous structure, in satisfactory agreement with the results of low-energy ion-beam experiments. We also find that the crossover between low- and high-density films is associated with a tensile to compressive stress transition, and a simultaneous healing of structural defects of the {\em a-}SiO2_2 network, namely three- and four-fold rings. It is observed, finally, that densification proceeds through significant changes at intermediate length scales (4--10 \AA), leaving essentially unchanged the ``building blocks'' of the network, viz. the Si(O1/2_{1/2})4_{4} tetrahedra. This latter result is in qualitative agreement with the mechanism proposed to explain the irreversible densification of amorphous silica recovered from high pressures (\sim 15--20 GPa).Comment: 12 pages including 10 postscript figures; submitted to Phys. Rev. B; related publications can be found on web site http://www.centrcn.umontreal.ca/~lewi

    Agent-Based Team Aiding in a Time Critical Task

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    In this paper we evaluate the effectiveness of agent-based aiding in support of a time-critical team-planning task for teams of both humans and heterogeneous software agents. The team task consists of human subjects playing the role of military commanders and cooperatively planning to move their respective units to a common rendezvous point, given time and resource constraints. The objective of the experiment was to compare the effectiveness of agent-based aiding for individual and team tasks as opposed to the baseline condition of manual route planning. There were two experimental conditions: the Aided condition, where a Route Planning Agent (RPA) finds a least cost plan between the start and rendezvous points for a given composition of force units; and the Baseline condition, where the commanders determine initial routes manually, and receive basic feedback about the route. We demonstrate that the Aided condition provides significantly better assistance for individual route planning and team-based re-planning

    ARAS: an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes.

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    BackgroundAutomated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing a safe environment for radiation workers but also to ensure accuracy of dispensed radioactivity and an efficient workflow. For this purpose, we have designed ARAS, an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes with particular focus on fluorine-18 ((18)F).MethodsThe key to the system is the combination of a radiation detector measuring radioactivity concentration, in line with a peristaltic pump dispensing known volumes.ResultsThe combined system demonstrates volume variation to be within 5 % for dispensing volumes of 20 μL or greater. When considering volumes of 20 μL or greater, the delivered radioactivity is in agreement with the requested amount as measured independently with a dose calibrator to within 2 % on average.ConclusionsThe integration of the detector and pump in an in-line system leads to a flexible and compact approach that can accurately dispense solutions containing radioactivity concentrations ranging from the high values typical of [(18)F]fluoride directly produced from a cyclotron (~0.1-1 mCi μL(-1)) to the low values typical of batches of [(18)F]fluoride-labeled radiotracers intended for preclinical mouse scans (~1-10 μCi μL(-1))

    In vitro evaluation of In-111-DOTA-anti-bcl-2-PNA-Tyr-3-octreotate in Chronic Lymphocytic Leukemia cells

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    Abstract only availableThe B-cell lymphoma/leukemia-2 (bcl-2) gene is overexpressed in many cancers. This gene increases cell survival by blocking apoptosis, or programmed cell death. The objective of this study was to evaluate radiolabeled peptide nucleic acid (PNA)-peptide conjugates targeting bcl-2 gene expression. DOTA-anti-bcl-2-PNA-Tyr-3-octreotate conjugate was labeled with In-111. Uptake, internalization, and efflux studies were performed in the human chronic lymphocytic leukemia (CLL) cell line Mec-1, which expresses both somatostatin receptors and bcl-2 mRNA. In the conjugate, octreotate is the somatostatin receptor ligand. Receptor and mRNA binding were also evaluated. Internalization of In-111-DOTA-anti-bcl-2-PNA-octreotate increased from 58.29% at 1min to 67.9% at 15min and reached 81% at 4h, whereas the internalized In-111-DOTA-Tyr-3-octreotate in Mec-1 cells started from 31.1% at 1min and gradually increased to 49.28% and 66.1% at 15min and 4h, respectively. Efflux analysis of Mec-1-In-111-DOTA-anti-bcl-2-PNA-Tyr-3-octreotate showed that 84.9% of radioactivity remained in the cells after 1min incubation and 60.0% of cell associated radioactivity was retained 4h later. Analysis of In-111-DOTA-Tyr-3-octreotate showed the cell associated radioactivity dropped from 85.1% at 1min to 69.1% at 4h.The western blot assay study showed a 51.0% bcl-2 protein synthesis inhibition by treatment with DOTA-anti-bcl-2-PNA-Tyr-3-octreotate. As a result, a peptide conjugate, which contains two molecular functions, was developed. These functions are receptor mediated tumor cell delivery and oncogene mRNA targeting. This agent has the potential to be used for detection of tumor bcl-2 expression by non-invasive molecular imaging.Louis Stokes Missouri Alliance for Minority Participatio

    Engineering spin squeezing in a 3D optical lattice with interacting spin-orbit-coupled fermions

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    One of the most important tasks in modern quantum science is to coherently control and entangle many-body systems, and to subsequently use these systems to realize powerful quantum technologies such as quantum-enhanced sensors. However, many-body entangled states are difficult to prepare and preserve since internal dynamics and external noise rapidly degrade any useful entanglement. Here, we introduce a protocol that counterintuitively exploits inhomogeneities, a typical source of dephasing in a many-body system, in combination with interactions to generate metrologically useful and robust many-body entangled states. Motivated by current limitations in state-of-the-art three-dimensional (3D) optical lattice clocks (OLCs) operating at quantum degeneracy, we use local interactions in a Hubbard model with spin-orbit coupling to achieve a spin-locking effect. In addition to prolonging inter-particle spin coherence, spin-locking transforms the dephasing effect of spin-orbit coupling into a collective spin-squeezing process that can be further enhanced by applying a modulated drive. Our protocol is fully compatible with state-of-the-art 3D OLC interrogation schemes and may be used to improve their sensitivity, which is currently limited by the intrinsic quantum noise of independent atoms. We demonstrate that even with realistic experimental imperfections, our protocol may generate 10\sim10--1414 dB of spin squeezing in 1\sim1 second with 102\sim10^2--10410^4 atoms. This capability allows OLCs to enter a new era of quantum enhanced sensing using correlated quantum states of driven non-equilibrium systems.Comment: 20 pages, 12 figure

    Computer graphics interactive workshop for two-dimensional fractals

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    We present in this study an interactive computer graphics workshop for two-dimensional fractals. The workshop enables the user to learn about fractals through experimentation with the generation of Koch-like fractal curves. A variety of Koch-like fractal curves, Julia sets and the Mandelbrot set are presented as examples. Algorithms are presented for creating the Mandelbrot set and for creating Kock-like fractal curves. Keywords and Phrases: fractals, Kock-like Fractal curves, Julia sets, interactive computer graphicsU.S. Army Combat Development Experimentation Center (USACDEC) under MIPR ATEC 46-86 and in part by funds provided through the Commodore Grace Murray Hopper Research Chair in Computer Science at the Naval Postgraduate School.http://archive.org/details/computergraphicsin00masoN0003986WRDQ200N
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