901 research outputs found
The Value of "Value Pricing" of Roads: Second-Best Pricing and Product Differentiation
No full textSome road-pricing demonstrations use an approach called "value pr icing", in which travelers can choose between a free but congested roadway and a priced roadway. Recent research has uncovered a potentially serious problem for such demonstrations: in certain models, second-best tolls are far lower than those typically charged, and the welfare gains from profit maximization are small or even negative. That research, however , assumes that all travelers are identical, and it therefore neglects the benefits of product differentiation, by which people with different values of time can choose a suitable cost/quality combination. Using a model with two user groups, we find that accounting for heterogeneity in value of time is important in evaluating constrained policies, and improves the relative performance of policies that offer differential prices. Nevertheless, for most of the reasonable range of heterogeneity, second-best pricing produces far fewer benefits than pricing both roadways optimally, and profit-maximizing tolls are so high that over all welfare is reduced from the no-toll baseline.
The Colorado Trust’s Healthy Communities Initiative: Results and Lessons for Comprehensive Community Initiatives
No full text· This article summarizes how 29 diverse communities throughout Colorado implemented the Colorado Healthy Communities Initiative (CHCI), which was conceived and funded by The Colorado Trust to engage community residents in the development of locally relevant strategies to improve community health.
· In line with the World Health Organization’s Healthy Cities model, CHCI emphasized (a) inclusive, representative planning; (b) a broad definition of “health”; (c) consensus decision making; and (d) capacity building among local stakeholder groups.
· Communities implemented an array of projects (on average, six per community) that extended well beyond traditional health promotion and disease prevention. The most common action projects focused on community problem solving, civic engagement, and youth development. Many of the grantees established projects or new institutions that had a long-term community impact.
· Key success factors for CHCI included (a) a wellspecified planning model, (b) a planning process facilitated by expert consultants, (c) a unifying “healthy community” vision developed at the beginning of the process by diverse stakeholders, (d) a willingness by stakeholders to work collaboratively to define “key performance areas” and then to implement “action projects” to achieve them, and (e) an appropriate level of funding for implementation ($50,000 per site per year).
· The outcomes and impacts of CHCI might have been improved by better anticipating the requirements for sustaining the energy and work initiated during the planning process.
· At the end of the initiative, CHCI provided the funders with a broader, deeper understanding of the requirements, opportunities, and realities associated with promoting “community health.
Author Correction: Transcript expression-aware annotation improves rare variant interpretation
No full textIn this Article, author Marquis P. Vawter was missing from the Genome Aggregation Database Consortium list. They are associated with the affiliation: ‘Department of Psychiatry & Human Behavior, University of California Irvine, Irvine, CA, USA’, and contributed to the generation of the primary data incorporated into the gnomAD resource. The original Article has been corrected online
The Keck Carbon Cycle AMS Laboratory, University of California, Irvine : status report
No full textAuthor Posting. © The Authors. This work is licensed under a Creative Commons Attribution 3.0 License The definitive version was published in Radiocarbon 52 (2010): 301-309.We present a status report of the accelerator mass spectrometry (AMS) facility at the University of California,
Irvine, USA. Recent spectrometer upgrades and repairs are discussed. Modifications to preparation laboratory procedures
designed to improve sample throughput efficiency while maintaining precision of 2–3‰ for 1-mg samples (Santos et al.
2007c) are presented
Microturbulence in DIII-D tokamak pedestal. I. Electrostatic instabilities
No full textGyrokinetic simulations of electrostatic driftwave instabilities in a tokamak edge have been carried out to study the turbulent transport in the pedestal of an H-mode plasma. The simulations use annulus geometry and focus on two radial regions of a DIII-D experiment: the pedestal top with a mild pressure gradient and the middle of the pedestal with a steep pressure gradient. A reactive trapped electron instability with a typical ballooning mode structure is excited by trapped electrons in the pedestal top. In the middle of the pedestal, the electrostatic instability exhibits an unusual mode structure, which peaks at the poloidal angle theta = +/-pi/2. The simulations find that this unusual mode structure is due to the steep pressure gradients in the pedestal but not due to the particular DIII-D magnetic geometry. Realistic DIII-D geometry appears to have a stabilizing effect on the instability when compared to a simple circular tokamak geometry. (C) 2014 AIP Publishing LLC.Physics, Fluids & PlasmasSCI(E)[email protected]
A Notch Sweeter
No full textNotch is a key signaling protein mediating cell-fate decisions during development. In this issue, Acar et al. (2008) describe a new gene called rumi that is required for Notch signaling in Drosophila. This gene encodes an O-glucosyltransferase that attaches glucose sugars to serine residues in the multiple EGF domains of the extracellular region of Notch. This modification by Rumi likely influences Notch folding and trafficking
Intertextual Episodes in Lectures: A Classification from the Perspective of Incidental Learning from Reading
No full textIn a parallel language environment it is important that teaching takes account of both the languages students are expected to work in. Lectures in the mother tongue need to offer access to textbooks in English and encouragement to read. This paper describes a preliminary study for an investigation of the extent to which they actually do so. A corpus of lectures in English for mainly L1 English students (from BASE and MICASE) was examined for the types of reference to reading which occur, classifi ed by their potential usefulness for access and encouragement. Such references were called ‘intertextual episodes’. Seven preliminary categories of intertextual episode were identifi ed. In some disciplines the text is the topic of the lecture rather than a medium for information on the topic, and this category was not pursued further. In the remaining six the text was a medium for information about the topic. Three of them involved management, of texts by the lecturer her/himself, of student writing, or of student reading. The remaining three involved reference to the content of the text either introducing it to students, reporting its content, or, really the most interesting category, relativizing it and thus potentially encouraging critical reading. Straightforward reporting that certain content was in the text at a certain point was the most common type, followed by management of student reading. Relativization was relatively infrequent. The exercise has provided us with categories which can be used for an experimental phase where the effect of different types of reference can be tested, and for observation of the references actually used in L1 lectures in a parallel-language environment
Author Correction: The mutational constraint spectrum quantified from variation in 141,456 humanS
No full textIn this Article, author Marquis P. Vawter was missing from the Genome Aggregation Database Consortium list. They are associated with the affiliation: ‘Department of Psychiatry & Human Behavior, University of California Irvine, Irvine, CA, USA’, and contributed to the generation of the primary data incorporated into the gnomAD resource. In addition, in the legend to Fig. 1, ‘ten’ should have been ‘seven’ in the sentence: “a, Uniform manifold approximation and projection (UMAP)46,47 plot depicting the ancestral diversity of all individuals in gnomAD, using seven principal components.” The original Article has been corrected online
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