57 research outputs found

    The Effect of Charge Display on Cost of Care and Physician Practice Behaviors: A Systematic Review

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    BACKGROUND: While studies have been published in the last 30 years that examine the effect of charge display during physician decision-making, no analysis or synthesis of these studies has been conducted. OBJECTIVE: We aimed to determine the type and quality of charge display studies that have been published; to synthesize this information in the form of a literature review. METHODS: English-language articles published between 1982 and 2013 were identified using MEDLINE, Web of Knowledge, ABI-Inform, and Academic Search Premier. Article titles, abstracts, and text were reviewed for relevancy by two authors. Data were then extracted and subsequently synthesized and analyzed. RESULTS: Seventeen articles were identified that fell into two topic categories: the effect of charge display on radiology and laboratory test ordering versus on medication choice. Seven articles were randomized controlled trials, eight were pre-intervention vs. post-intervention studies, and two interventions had a concurrent control and intervention groups, but were not randomized. Twelve studies were conducted in a clinical environment, whereas five were survey studies. Of the nine clinically based interventions that examined test ordering, seven had statistically significant reductions in cost and/or the number of tests ordered. Two of the three clinical studies looking at medication expenditures found significant reductions in cost. In the survey studies, physicians consistently chose fewer tests or lower cost options in the theoretical scenarios presented. CONCLUSIONS: In the majority of studies, charge information changed ordering and prescribing behavior

    Impact of brain tissue filtering on neurostimulation fields: A modeling study

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    Electrical neurostimulation techniques, such as deep brain stimulation (DBS) and transcranial magnetic stimulation (TMS), are increasingly used in the neurosciences, e.g., for studying brain function, and for neurotherapeutics, e.g., for treating depression, epilepsy, and Parkinson's disease. The characterization of electrical properties of brain tissue has guided our fundamental understanding and application of these methods, from electrophysiologic theory to clinical dosing-metrics. Nonetheless, prior computational models have primarily relied on ex-vivo impedance measurements. We recorded the in-vivo impedances of brain tissues during neurosurgical procedures and used these results to construct MRI guided computational models of TMS and DBS neurostimulatory fields and conductance-based models of neurons exposed to stimulation. We demonstrated that tissues carry neurostimulation currents through frequency dependent resistive and capacitive properties not typically accounted for by past neurostimulation modeling work. We show that these fundamental brain tissue properties can have significant effects on the neurostimulatory-fields (capacitive and resistive current composition and spatial/temporal dynamics) and neural responses (stimulation threshold, ionic currents, and membrane dynamics). These findings highlight the importance of tissue impedance properties on neurostimulation and impact our understanding of the biological mechanisms and technological potential of neurostimulatory methods.United States. Defense Advanced Research Projects Agency (Contract W31P4Q-09-C-0117)National Institute of Neurological Disorders and Stroke (U.S.) (Award R43NS062530)National Institute of Neurological Disorders and Stroke (U.S.) (Award 1R44NS080632

    Performance/mathematics: a dramatisation of mathematical methods

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    This essay conceptualises the notion of performance mathematics in terms of a paradoxical relationship with the constructed notion of truth, which is shared by theatrical and mathematical performance. Specifically, I argue that these two disciplines can and cannot be reconciled with truthfulness. Grounding my comparison on the notion of an axiomatic method common to both disciplines, I argue that theatrical and mathematical performance can speak of truths only when these truths are properly staged or methodologically grounded according to the internal rules and conditions laid out by each discipline. But in the same way that these truths can be constructed, or they can be done, so they can be undone. Arguing that mathematics can be described as a performance of specific outcomes involving abstract objects and functions, I trace a cross-disciplinary comparative analysis of performance elements (especially axioms and functions), drawing on a number of theatre and mathematical theories. Some suggestions are also put forward in terms of the connection between the performance of mathematised texts and computational mathematics, particularly in terms of an inherent poetics and theatricality inside the performance-oriented, mathematised languages of digital computing

    Effects of ocean sprawl on ecological connectivity: impacts and solutions

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    The growing number of artificial structures in estuarine, coastal and marine environments is causing “ocean sprawl”. Artificial structures do not only modify marine and coastal ecosystems at the sites of their placement, but may also produce larger-scale impacts through their alteration of ecological connectivity - the movement of organisms, materials and energy between habitat units within seascapes. Despite the growing awareness of the capacity of ocean sprawl to influence ecological connectivity, we lack a comprehensive understanding of how artificial structures modify ecological connectivity in near- and off-shore environments, and when and where their effects on connectivity are greatest. We review the mechanisms by which ocean sprawl may modify ecological connectivity, including trophic connectivity associated with the flow of nutrients and resources. We also review demonstrated, inferred and likely ecological impacts of such changes to connectivity, at scales from genes to ecosystems, and potential strategies of management for mitigating these effects. Ocean sprawl may alter connectivity by: (1) creating barriers to the movement of some organisms and resources - by adding physical barriers or by modifying and fragmenting habitats; (2) introducing new structural material that acts as a conduit for the movement of other organisms or resources across the landscape; and (3) altering trophic connectivity. Changes to connectivity may, in turn, influence the genetic structure and size of populations, the distribution of species, and community structure and ecological functioning. Two main approaches to the assessment of ecological connectivity have been taken: (1) measurement of structural connectivity - the configuration of the landscape and habitat patches and their dynamics; and (2) measurement of functional connectivity - the response of organisms or particles to the landscape. Our review reveals the paucity of studies directly addressing the effects of artificial structures on ecological connectivity in the marine environment, particularly at large spatial and temporal scales. With the ongoing development of estuarine and marine environments, there is a pressing need for additional studies that quantify the effects of ocean sprawl on ecological connectivity. Understanding the mechanisms by which structures modify connectivity is essential if marine spatial planning and eco-engineering are to be effectively utilised to minimise impacts

    On groups of finite height

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    Characteristics of visits, 2002–2003 and 2008–2009<sup>a</sup>.

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    a<p>Weighted percentages based on the sample that was surveyed.</p>b<p>Variable not available in the 2002 and 2003 databases.</p

    Changes in possible reasons for increased PPI use.

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    <p>Changes in possible reasons for increased PPI use.</p

    Proton pump inhibitors and H<sub>2</sub>-blockers used in the U.S.

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    <p>Proton pump inhibitors and H<sub>2</sub>-blockers used in the U.S.</p
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