Increasing Beach Recreation Benefits by Using Wetlands to Reduce Contamination

The public swimming beach at Maumee Bay State Park (MBSP) on Lake Erie is often posted for occurrences of unsafe levels of bacteria. The main source of bacteria derives from a drainage ditch that discharges near the beach. We have conducted a comprehensive study to determine the feasibility of using a constructed wetland to filter the ditch water, prior to its entry into Maumee Bay. As part of this study, we administered an on-site non-market valuation survey of beach visitors, in which observed and contingent trips to the beach were used to estimate the potential welfare benefits of the restored wetlands. The data were analyzed using three versions of the multivariate Poisson-lognormal (MPLN) model, a random effects count data model. We conclude version one, with flexible covariance structure and vehicle costs of $0.25 per mile, is the preferred version and use it to estimate an average annual willingness to pay (WTP) of$166 to construct wetlands and improve water quality. The aggregate annual benefit to an estimated 37,300 annual beach visitors is estimated as $6.19 million. The robustness of this estimate to a variety of alternative assumptions is examined.Count data model, Poisson lognormal, on-site sampling, recreation demand, wetland, simulated maximum likelihood, Community/Rural/Urban Development, Environmental Economics and Policy, Public Economics, Q51,

Re-Evaluating Subsidies for Services That Carry no Positive Externalities: A Benefit-Cost Analysis of Convenience Loop Busing versus Walking

This paper seeks to provide a benefit-cost analysis of continuous loop busing service offered by The University of Toledo in Toledo, Ohio. The on-campus busing service is completely subsidized by the university through student fees and provided as a free service to students with less than one-quarter of students currently using the service. Using a contingent valuation survey, we estimate a lower bound mean willingness to pay (WTP) of about $6 per student user per semester. Multiplying by the student body population leads to a total WTP estimate of approximately$37,000 per semester. When compared solely to labor and fuel costs to operate the loop busing, costs outweighed benefits $41,000 to$37,000. This does not include maintenance costs on the buses, pollution from burning diesel fuel, or the opportunity cost incurred when students are riding instead of walking. There are no positive externalities from Toledo on-campus busing since it’s only a convenience service to shuttle students from parking and from building to building. Students use the service when it carries an artificially low cost of zero dollars, for which they could walk in approximately the same amount of time, with walking being an activity that would provide positive externalities to society through the known health benefits from exercise

Valuing Water Quality As a Functionof Water Quality Measures

This paper incorporates a rich set of physical water quality attributes, as well as site and household characteristics, into a model of recreational lake usage in Iowa. Our analysis shows individuals are responsive to physical water quality measures. Willingness-to-pay estimates are reported based on improvements in these measures.

A Semiparametric Smooth Coefficient Estimator for Recreation Demand

We introduce a semiparametric smooth coefficient estimator for recreation demand data that allows more flexible modeling of preference heterogeneity. We show that our sample of visitors each has an individual statistically significant price coefficient estimate leading to clearly nonparametric consumer surplus and willingness to pay (WTP) distributions. We also show mean WTP estimates that are different in economically meaningful ways for every demographic variable we have for our sample of beach visitors. This flexibility is valuable for future researchers who can include any variables of interest beyond the standard demographic variables we have included here. And the richer results, price elasticities, consumer surplus and WTP estimates, are valuable to planners and policymakers who can easily see how all these estimates vary with characteristics of the population of interest

The designability of protein switches by chemical rescue of structure: mechanisms of inactivation and reactivation

This document is the Accepted Manuscript version of a Published Work that appeared in final form in the Journal of the American Chemical Society, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/ja407644b.The ability to selectively activate function of particular proteins via pharmacological agents is a longstanding goal in chemical biology. Recently, we reported an approach for designing a de novo allosteric effector site directly into the catalytic domain of an enzyme. This approach is distinct from traditional chemical rescue of enzymes in that it relies on disruption and restoration of structure, rather than active site chemistry, as a means to achieve modulate function. However, rationally identifying analogous de novo binding sites in other enzymes represents a key challenge for extending this approach to introduce allosteric control into other enzymes. Here we show that mutation sites leading to protein inactivation via tryptophan-to-glycine substitution and allowing (partial) reactivation by the subsequent addition of indole are remarkably frequent. Through a suite of methods including a cell-based reporter assay, computational structure prediction and energetic analysis, fluorescence studies, enzymology, pulse proteolysis, x-ray crystallography and hydrogen-deuterium mass spectrometry we find that these switchable proteins are most commonly modulated indirectly, through control of protein stability. Addition of indole in these cases rescues activity not by reverting a discrete conformational change, as we had observed in the sole previously reported example, but rather rescues activity by restoring protein stability. This important finding will dramatically impact the design of future switches and sensors built by this approach, since evaluating stability differences associated with cavity-forming mutations is a far more tractable task than predicting allosteric conformational changes. By analogy to natural signaling systems, the insights from this study further raise the exciting prospect of modulating stability to design optimal recognition properties into future de novo switches and sensors built through chemical rescue of structure

Brief Report: Long‐Term Functional Engraftment of Mesenchymal Progenitor Cells in a Mouse Model of Accelerated Aging

Age‐related osteoporosis is characterized by a decrease in bone‐forming capacity mediated by defects in the number and function of osteoblasts. An important cellular mechanism that may in part explain osteoblast dysfunction that occurs with aging is senescence of mesenchymal progenitor cells (MPCs). In the telomere‐based Wrn −/− Terc −/− model of accelerated aging, the osteoporotic phenotype of these mice is also associated with a major decline in MPC differentiation into osteoblasts. To investigate the role of MPC aging as a cell‐autonomous mechanism in senile bone loss, transplantation of young wild‐type whole bone marrow into Wrn −/− Terc −/− mutants was performed and the ability of engrafted cells to differentiate into cells of the osteoblast lineage was assessed. We found that whole bone marrow transplantation in Wrn −/− Terc −/− mice resulted in functional engraftment of MPCs up to 42 weeks, which was accompanied by a survival advantage as well as delays in microarchitectural features of skeletal aging. S TEM C ELLS 2013;31:607–611Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96667/1/sc-12-0760_sm_SupplFigure1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96667/2/1294_ftp.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96667/3/sc-12-0760_sm_SupplFigure2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96667/4/sc-12-0760_sm_SupplFigure3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96667/5/sc-12-0760_sm_SupplInform.pd

Frequency Analysis and Sheared Reconstruction for Rendering Motion Blur

International audienceMotion blur is crucial for high-quality rendering but is also very expensive. Our first contribution is a frequency analysis of motion-blurred scenes, including moving objects, specular reflections, and shadows. We show that motion induces a shear in the frequency domain, and that the spectrum of moving scenes is usually contained in a wedge. This allows us to compute adaptive space-time sampling rates, to accelerate rendering. For uniform velocities and standard axis-aligned reconstruction, we show that the product of spatial and temporal bandlimits or sampling rates is constant, independent of velocity. Our second contribution is a novel sheared reconstruction filter that tightly packs the wedge of frequencies in the Fourier domain, and enables even lower sampling rates. We present a rendering algorithm that computes a sheared reconstruction filter per pixel, without any intermediate Fourier representation. This often permits synthesis of motion-blurred images with far fewer rendering samples than standard techniques require

Deconvolution of Images from BLAST 2005: Insight into the K3-50 and IC 5146 Star-Forming Regions

We present an implementation of the iterative flux-conserving Lucy-Richardson (L-R) deconvolution method of image restoration for maps produced by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST). We have analyzed its performance and convergence extensively through simulations and cross-correlations of the deconvolved images with available highresolution maps. We present new science results from two BLAST surveys, in the Galactic regions K3-50 and IC 5146, further demonstrating the benefits of performing this deconvolution. We have resolved three clumps within a radius of 4.'5 inside the star-forming molecular cloud containing K3-50. Combining the well-resolved dust emission map with available multi-wavelength data, we have constrained the Spectral Energy Distributions (SEDs) of five clumps to obtain masses (M), bolometric luminosities (L), and dust temperatures (T). The L-M diagram has been used as a diagnostic tool to estimate the evolutionary stages of the clumps. There are close relationships between dust continuum emission and both 21-cm radio continuum and 12CO molecular line emission. The restored extended large scale structures in the Northern Streamer of IC 5146 have a strong spatial correlation with both SCUBA and high resolution extinction images. A dust temperature of 12 K has been obtained for the central filament. We report physical properties of ten compact sources, including six associated protostars, by fitting SEDs to multi-wavelength data. All of these compact sources are still quite cold (typical temperature below ~ 16 K) and are above the critical Bonner-Ebert mass. They have associated low-power Young Stellar Objects (YSOs). Further evidence for starless clumps has also been found in the IC 5146 region.Comment: 13 pages, 12 Figures, 3 Table